Can antioxidant-rich spices counteract the effects of a high-fat meal?

A High Antioxidant Spice Blend Attenuates Postprandial Insulin and Triglyceride Responses and Increases Some Plasma Measures of Antioxidant Activity in Healthy, Overweight Men

There is much interest in the potential of dietary antioxidants to attenuate in vivo oxidative stress, but little characterization of the time course of plasma effects exists. Culinary spices have demonstrated potent in vitro antioxidant properties. The objective of this study was to examine whether adding 14 g of a high antioxidant spice blend to a 5060-kJ (1200 kcal) meal exerted significant postprandial effects on markers of plasma antioxidant status and metabolism. Healthy overweight men (n = 6) consumed a control and spiced meal in a randomized crossover design with 1 wk between testing sessions. Blood was sampled prior to the meal and at 30-min intervals for 3.5 h (total of 8 samples). Mixed linear models demonstrated a treatment × time interaction (P < 0.05) for insulin and TG, corresponding with 21 and 31% reductions in postprandial levels with the spiced meal, respectively. Adding spices to the meal significantly increased the ferric reducing antioxidant power, such that postprandial increases following the spiced meal were 2-fold greater than after the control meal (P = 0.009). The hydrophilic oxygen radical absorbance capacity (ORAC) of plasma also was increased by spices (P = 0.02). There were no treatment differences in glucose, total thiols, lipophilic ORAC, or total ORAC. The incorporation of spices into the diet may help normalize postprandial insulin and TG and enhance antioxidant defenses.

Effect of dietary antioxidants on postprandial endothelial dysfunction induced by a high-fat meal in healthy subjects.

BACKGROUND: Persons following current dietary guidelines have a lower risk of mortality from coronary heart disease. OBJECTIVE: The objective was to compare the short-term effect of a high-fat meal and a high-carbohydrate meal, with and without dietary antioxidants, on vasomotor, antiplatelet, and hemostatic functions of the endothelium in healthy subjects. DESIGN: In an observer-blinded, randomized crossover study, 25 (13 men and 12 women) healthy subjects were given each of 3 meals in random order at 1-wk intervals: a high-fat meal (760 kcal), an isoenergetic high-carbohydrate meal, and a high-fat meal with dietary antioxidants from vegetables (865 kcal). Endothelial functions, as assessed by hemodynamic and rheologic responses to L-arginine--the natural precursor of nitric oxide--were evaluated before and 4 h after each meal. RESULTS: Unlike the high-carbohydrate meal, the high-fat meal increased the plasma concentrations of triacylglycerol (P < 0.01); both meals activated hemostasis. The high-carbohydrate meal did not modify blood pressure, and platelet aggregation decreased in response to the L-arginine load (-7.1 +/- 2.3 mm Hg and -8.5 +/- 4.5%, respectively). After the high-fat meal, the decrease in blood pressure in response to L-arginine was reduced (-1 +/- 0.8 mm Hg), and platelet aggregation showed a paradoxical increase (4.1 +/- 2.1%; P < 0.01 compared with the high-carbohydrate meal). The high-fat meal with antioxidants partially restored the vascular response to L-arginine. CONCLUSION: Compared with a high-carbohydrate meal, a high-fat meal can modify endothelial functions toward a more atherogenetic profile, which is partially prevented by dietary antioxidants.

The Okinawan diet: health implications of a low-calorie, nutrient-dense, antioxidant-rich dietary pattern low in glycemic load.

Residents of Okinawa, the southernmost prefecture of Japan, are known for their long average life expectancy, high numbers of centenarians, and accompanying low risk of age-associated diseases. Much of the longevity advantage in Okinawa is thought to be related to a healthy lifestyle, particularly the traditional diet, which is low in calories yet nutritionally dense, especially with regard to phytonutrients in the form of antioxidants and flavonoids. Research suggests that diets associated with a reduced risk of chronic diseases are similar to the traditional Okinawan diet, that is, vegetable and fruit heavy (therefore phytonutrient and antioxidant rich) but reduced in meat, refined grains, saturated fat, sugar, salt, and full-fat dairy products. Many of the characteristics of the diet in Okinawa are shared with other healthy dietary patterns, such as the traditional Mediterranean diet or the modern DASH (Dietary Approaches to Stop Hypertension) diet. Features such as the low levels of saturated fat, high antioxidant intake, and low glycemic load in these diets are likely contributing to a decreased risk for cardiovascular disease, some cancers, and other chronic diseases through multiple mechanisms, including reduced oxidative stress. A comparison of the nutrient profiles of the three dietary patterns shows that the traditional Okinawan diet is the lowest in fat intake, particularly in terms of saturated fat, and highest in carbohydrate intake, in keeping with the very high intake of antioxidant-rich yet calorie-poor orange-yellow root vegetables, such as sweet potatoes, and green leafy vegetables. Deeper analyses of the individual components of the Okinawan diet reveal that many of the traditional foods, herbs, or spices consumed on a regular basis could be labeled "functional foods" and, indeed, are currently being explored for their potential health-enhancing properties.

The total antioxidant content of more than 3100 foods, beverages, spices, herbs and supplements used worldwide

Background A plant-based diet protects against chronic oxidative stress-related diseases. Dietary plants contain variable chemical families and amounts of antioxidants. It has been hypothesized that plant antioxidants may contribute to the beneficial health effects of dietary plants. Our objective was to develop a comprehensive food database consisting of the total antioxidant content of typical foods as well as other dietary items such as traditional medicine plants, herbs and spices and dietary supplements. This database is intended for use in a wide range of nutritional research, from in vitro and cell and animal studies, to clinical trials and nutritional epidemiological studies. Methods We procured samples from countries worldwide and assayed the samples for their total antioxidant content using a modified version of the FRAP assay. Results and sample information (such as country of origin, product and/or brand name) were registered for each individual food sample and constitute the Antioxidant Food Table. Results The results demonstrate that there are several thousand-fold differences in antioxidant content of foods. Spices, herbs and supplements include the most antioxidant rich products in our study, some exceptionally high. Berries, fruits, nuts, chocolate, vegetables and products thereof constitute common foods and beverages with high antioxidant values. Conclusions This database is to our best knowledge the most comprehensive Antioxidant Food Database published and it shows that plant-based foods introduce significantly more antioxidants into human diet than non-plant foods. Because of the large variations observed between otherwise comparable food samples the study emphasizes the importance of using a comprehensive database combined with a detailed system for food registration in clinical and epidemiological studies. The present antioxidant database is therefore an essential research tool to further elucidate the potential health effects of phytochemical antioxidants in diet.

Could a vegetarian diet reduce exercise-induced oxidative stress? A review of the literature.

Oxidative stress is a natural physiological process that describes an imbalance between free radical production and the ability of the antioxidant defence system of the body to neutralize free radicals. Free radicals can be beneficial as they may promote wound healing and contribute to a healthy immune response. However, free radicals can have a detrimental impact when they interfere with the regulation of apoptosis and thus play a role in the promotion of some cancers and conditions such as cardiovascular disease. Antioxidants are molecules that reduce the damage associated with oxidative stress by counteracting free radicals. Regular exercise is a vital component of a healthy lifestyle, although it can increase oxidative stress. As a typical vegetarian diet comprises a wide range of antioxidant-rich foods, it is plausible that the consumption of these foods will result in an enhanced antioxidant system capable of reducing exercise-induced oxidative stress. In addition, a relationship between a vegetarian diet and lower risks of cardiovascular disease and some cancers has been established. This review explores the current available evidence linking exercise, vegetarians, antioxidants, and oxidative stress.

Açai Palm Fruit (Euterpe oleracea Mart.) Pulp Improves Survival of Flies on a High Fat Diet

Reducing oxidative damage is thought to be an effective aging intervention. Açai, a fruit indigenous to the Amazon, is rich in phytochemicals that possesses high anti-oxidant activities, and has anti-inflammatory, anti-cancer and anti-cardiovascular disease properties. However, little is known about its potential anti-aging properties especially at the organismal level. Here we evaluated the effect of açai pulp on modulating lifespan in Drosophila melanogaster. We found that açai supplementation at 2% in the food increased the lifespan of female flies fed a high fat diet compared to the non-supplemented control. We measured transcript changes induced by açai for age-related genes. Although transcript levels of most genes tested were not altered, açai increased the transcript level of l(2)efl, a small heat-shock-related protein, and two detoxification genes, gstD1 and mtnA, while decreasing the transcript level of phosphoenolpyruvate carboxykinase (Pepck), a key gene involved in gluconeogenesis. Furthermore, açai increased the lifespan of oxidative stressed females caused by sod1 RNAi. This suggests that açai improves survival of flies fed a high fat diet through activation of stress response pathways and suppression of Pepck expression. Açai has the potential to antagonize the detrimental effect of fat in the diet and alleviate oxidative stress in aging.

Postprandial metabolic events and fruit-derived phenolics: a review of the science.

There is increasing evidence that the postprandial state is an important contributing factor to chronic disease. The role of fruit phenolic compounds to protect health and lower disease risk through their actions in mitigating fed-state metabolic and oxidative stressors is of interest and the topic of the present paper. Two main questions are posed: first, what is the role of plant foods, specifically fruits rich in complex and simple phenolic compounds in postprandial metabolic management; and second, does the evidence support consuming these fruits with meals as a practical strategy to preserve health and lower risk for disease? This review provides an overview of the postprandial literature, specifically on the effect of fruits and their inherent phenolic compounds in human subjects on postprandial lipaemia, glycaemia/insulinaemia and associated events, such as oxidative stress and inflammation. Among the identified well-controlled human trials using a postprandial paradigm, >50 % of the trials used wine or wine components and the remaining used various berries. Notwithstanding the need for more research, the collected data suggest that consuming phenolic-rich fruits increases the antioxidant capacity of the blood, and when they are consumed with high fat and carbohydrate 'pro-oxidant and pro-inflammatory' meals, they may counterbalance their negative effects. Given the content and availability of fat and carbohydrate in the Western diet, regular consumption of phenolic-rich foods, particularly in conjunction with meals, appears to be a prudent strategy to maintain oxidative balance and health.

Omega-3 fatty acids and antioxidants in edible wild plants.

Human beings evolved on a diet that was balanced in the omega-6 and omega-3 polyunsaturated fatty acids (PUFA), and was high in antioxidants. Edible wild plants provide alpha-linolenic acid (ALA) and higher amounts of vitamin E and vitamin C than cultivated plants. In addition to the antioxidant vitamins, edible wild plants are rich in phenols and other compounds that increase their antioxidant capacity. It is therefore important to systematically analyze the total antioxidant capacity of wild plants and promote their commercialization in both developed and developing countries. The diets of Western countries have contained increasingly larger amounts of linoleic acid (LA), which has been promoted for its cholesterol-lowering effect. It is now recognized that dietary LA favors oxidative modification of low density lipoprotein (LDL) cholesterol and increases platelet response to aggregation. In contrast, ALA intake is associated with inhibitory effects on the clotting activity of platelets, on their response to thrombin, and on the regulation of arachidonic acid (AA) metabolism. In clinical studies, ALA contributed to lowering of blood pressure, and a prospective epidemiological study showed that ALA is inversely related to the risk of coronary heart disease in men. Dietary amounts of LA as well as the ratio of LA to ALA appear to be important for the metabolism of ALA to longer-chain omega-3 PUFAs. Relatively large reserves of LA in body fat. as are found in vegans or in the diet of omnivores in Western societies, would tend to slow down the formation of long-chain omega-3 fatty acids from ALA. Therefore, the role of ALA in human nutrition becomes important in terms of long-term dietary intake. One advantage of the consumption of ALA over omega-3 fatty acids from fish is that the problem of insufficient vitamin E intake does not exist with high intake of ALA from plant sources.

Acute effects of high-fat meals enriched with walnuts or olive oil on postprandial endothelial function.

OBJECTIVES: We sought to investigate whether the addition of walnuts or olive oil to a fatty meal have differential effects on postprandial vasoactivity, lipoproteins, markers of oxidation and endothelial activation, and plasma asymmetric dimethylarginine (ADMA). BACKGROUND: Compared with a Mediterranean diet, a walnut diet has been shown to improve endothelial function in hypercholesterolemic patients. We hypothesized that walnuts would reverse postprandial endothelial dysfunction associated with consumption of a fatty meal. METHODS: We randomized in a crossover design 12 healthy subjects and 12 patients with hypercholesterolemia to 2 high-fat meal sequences to which 25 g olive oil or 40 g walnuts had been added. Both test meals contained 80 g fat and 35% saturated fatty acids, and consumption of each meal was separated by 1 week. Venipunctures and ultrasound measurements of brachial artery endothelial function were performed after fasting and 4 h after test meals. RESULTS: In both study groups, flow-mediated dilation (FMD) was worse after the olive oil meal than after the walnut meal (p = 0.006, time-period interaction). Fasting, but not postprandial, triglyceride concentrations correlated inversely with FMD (r = -0.324; p = 0.024). Flow-independent dilation and plasma ADMA concentrations were unchanged, and the concentration of oxidized low-density lipoproteins decreased (p = 0.051) after either meal. The plasma concentrations of soluble inflammatory cytokines and adhesion molecules decreased (p < 0.01) independently of meal type, except for E-selectin, which decreased more (p = 0.033) after the walnut meal. CONCLUSIONS: Adding walnuts to a high-fat meal acutely improves FMD independently of changes in oxidation, inflammation, or ADMA. Both walnuts and olive oil preserve the protective phenotype of endothelial cells.

Are free fatty acids effective taste stimuli in humans? Presented at the symposium "The Taste for Fat: New Discoveries on the Role of Fat in Sensor...

The popularity of low- and reduced-fat foods has increased as consumers seek to decrease their energy consumption. Fat replacers may be used in fat-reduced products to maintain their sensory properties. However, these ingredients have been largely formulated to replicate nongustatory properties of fats to foods and have only achieved moderate success. There is increasing evidence that fats also activate the taste system and uniquely evoke responses that may influence product acceptance. Work supporting a taste component of fat has prompted questions about whether fat constitutes an additional "primary" or "basic" taste quality. This review briefly summarizes this evidence, focusing on human studies, when possible. Effective stimuli, possible receptors, and physiological changes due to oral fat exposure are discussed. Some studies suggest that there are fatty acid tasters and nontasters and if verified could have implications for targeted product development. © 2011 Institute of Food Technologists®

Fostering antioxidant defences: up-regulation of antioxidant genes or antioxidant supplementation?

Vitamins have traditionally been considered as food components that are required in the normal diet to prevent deficiencies. However, a newer concept of the function of vitamins in nutrition has taken them beyond simply prevention of deficiency symptoms. This concept considers that many vitamins, when taken in relatively large doses, have important functions beyond preventing deficiencies. Linus Pauling was instrumental in putting forward this concept, particularly for vitamin C. Thus, relatively high intakes of vitamins, and in particular vitamins C and E which are antioxidants, are considered to be healthy for the human population. This may be true in some special situations such as, for instance, the prevention of Alzheimer's disease progression. However, recent epidemiological evidence has not supported the claim that antioxidant vitamins increase well-being and prolong life span. In fact, vitamin supplementation may be even detrimental and reduce life span. A new concept that we would like to put forward is that nutrients up-regulate the endogenous antioxidant defences. This is particularly true in the case of phytoestrogens for example, which bind to oestrogen receptors and eventually up-regulate the expression of antioxidant genes. In this review we discuss the pros and cons of antioxidant vitamin supplementation and also the possibility that the ingestion of some nutrients may be very effective in increasing antioxidant defences by up-regulating the activity of antioxidant enzymes which are normally present in the cell.

The postprandial effect of components of the Mediterranean diet on endothelial function.

OBJECTIVES: This study investigated the postprandial effect of components of the Mediterranean diet on endothelial function, which may be an atherogenic factor. BACKGROUND: The Mediterranean diet, containing olive oil, pasta, fruits, vegetables, fish, and wine, is associated with an unexpectedly low rate of cardiovascular events. The Lyon Diet Heart Study found that a Mediterranean diet, which substituted omega-3-fatty-acid-enriched canola oil for the traditionally consumed omega-9 fatty-acid-rich olive oil, reduced cardiovascular events. METHODS: We fed 10 healthy, normolipidemic subjects five meals containing 900 kcal and 50 g fat. Three meals contained different fat sources: olive oil, canola oil, and salmon. Two olive oil meals also contained antioxidant vitamins (C and E) or foods (balsamic vinegar and salad). We measured serum lipoproteins and glucose and brachial artery flow-mediated vasodilation (FMD), an index of endothelial function, before and 3 h after each meal. RESULTS: All five meals significantly raised serum triglycerides, but did not change other lipoproteins or glucose 3 h postprandially. The olive oil meal reduced FMD 31% (14.3 +/- 4.2% to 9.9 +/- 4.5%, p = 0.008). An inverse correlation was observed between postprandial changes in serum triglycerides and FMD (r = -0.47, p < 0.05). The remaining four meals did not significantly reduce FMD. CONCLUSIONS: In terms of their postprandial effect on endothelial function, the beneficial components of the Mediterranean and Lyon Diet Heart Study diets appear to be antioxidant-rich foods, including vegetables, fruits, and their derivatives such as vinegar, and omega-3-rich fish and canola oils.

Vegan proteins may reduce risk of cancer, obesity, and cardiovascular disease by promoting increased glucagon activity.

Amino acids modulate the secretion of both insulin and glucagon; the composition of dietary protein therefore has the potential to influence the balance of glucagon and insulin activity. Soy protein, as well as many other vegan proteins, are higher in non-essential amino acids than most animal-derived food proteins, and as a result should preferentially favor glucagon production. Acting on hepatocytes, glucagon promotes (and insulin inhibits) cAMP-dependent mechanisms that down-regulate lipogenic enzymes and cholesterol synthesis, while up-regulating hepatic LDL receptors and production of the IGF-I antagonist IGFBP-1. The insulin-sensitizing properties of many vegan diets--high in fiber, low in saturated fat--should amplify these effects by down-regulating insulin secretion. Additionally, the relatively low essential amino acid content of some vegan diets may decrease hepatic IGF-I synthesis. Thus, diets featuring vegan proteins can be expected to lower elevated serum lipid levels, promote weight loss, and decrease circulating IGF-I activity. The latter effect should impede cancer induction (as is seen in animal studies with soy protein), lessen neutrophil-mediated inflammatory damage, and slow growth and maturation in children. In fact, vegans tend to have low serum lipids, lean physiques, shorter stature, later puberty, and decreased risk for certain prominent 'Western' cancers; a vegan diet has documented clinical efficacy in rheumatoid arthritis. Low-fat vegan diets may be especially protective in regard to cancers linked to insulin resistance--namely, breast and colon cancer--as well as prostate cancer; conversely, the high IGF-I activity associated with heavy ingestion of animal products may be largely responsible for the epidemic of 'Western' cancers in wealthy societies. Increased phytochemical intake is also likely to contribute to the reduction of cancer risk in vegans. Regression of coronary stenoses has been documented during low-fat vegan diets coupled with exercise training; such regimens also tend to markedly improve diabetic control and lower elevated blood pressure. Risk of many other degenerative disorders may be decreased in vegans, although reduced growth factor activity may be responsible for an increased risk of hemorrhagic stroke. By altering the glucagon/insulin balance, it is conceivable that supplemental intakes of key non-essential amino acids could enable omnivores to enjoy some of the health advantages of a vegan diet. An unnecessarily high intake of essential amino acids--either in the absolute sense or relative to total dietary protein--may prove to be as grave a risk factor for 'Western' degenerative diseases as is excessive fat intake.

Effect of a single high-fat meal on endothelial function in healthy subjects.

Although there is a well-established relation between serum cholesterol and coronary artery disease risk, individual and national variations in this association suggest that other factors are involved in atherogenesis. High-fat diet associated triglyceride-rich lipoproteins have also been suggested to be atherogenic. To assess the direct effect of postprandial triglyceride-rich lipoproteins on endothelial function, an early factor in atherogenesis--10 healthy, normocholesterolemic volunteers--were studied before and for 6 hours after single isocaloric high- and low-fat meals (900 calorie; 50 and 0 g fat, respectively). Endothelial function, in the form of flow-mediated vasoactivity, was assessed in the brachial artery using 7.5-MHz ultrasound as percent arterial diameter change 1 minute after 5 minutes of upper-arm arterial occlusion. Serum lipoproteins and glucose were determined before eating and 2 and 4 hours postprandially. Serum triglycerides increased from 94 +/- 55 mg/dl preprandially to 147 +/- 80 mg/dl 2 hours after the high-fat meal (p = 0.05). Flow-dependent vasoactivity decreased from 21 +/- 5% preprandially to 11 +/- 4%, 11 +/- 6%, and 10 +/- 3% at 2, 3, and 4 hours after the high-fat meal, respectively (all p <0.05 compared with low-fat meal data). No changes in lipoproteins or flow-mediated vasoactivity were observed after the low-fat meal. Fasting low-density lipoprotein cholesterol correlated inversely (r = -0.47, p = 0.04) with preprandial flow-mediated vasoactivity, but triglyceride level did not. Mean change in postprandial flow-mediated vasoactivity at 2, 3, and 4 hours correlated with change in 2-hour serum triglycerides (r = -0.51, p = 0.02). These results demonstrate that a single high-fat meal transiently impairs endothelial function. These findings identify a potential process by which a high-fat diet may be atherogenic independent of induced changes in cholesterol.

High-antioxidant potatoes: acute in vivo antioxidant source and hypotensive agent in humans after supplementation to hypertensive subjects.

Potatoes have the highest daily per capita consumption of all vegetables in the U.S. diet. Pigmented potatoes contain high concentrations of antioxidants, including phenolic acids, anthocyanins, and carotenoids. In a single-dose study six to eight microwaved potatoes with skins or a comparable amount of refined starch as cooked biscuits was given to eight normal fasting subjects; repeated samples of blood were taken over an 8 h period. Plasma antioxidant capacity was measured by ferric reducing antioxidant power (FRAP). A 24 h urine was taken before and after each regimen. Urine antioxidant capacity due to polyphenol was measured by Folin reagent after correction for nonphenolic interferences with a solid phase (Polyclar) procedure. Potato caused an increase in plasma and urine antioxidant capacity, whereas refined potato starch caused a decrease in both; that is, it acted as a pro-oxidant. In a crossover study 18 hypertensive subjects with an average BMI of 29 were given either six to eight small microwaved purple potatoes twice daily or no potatoes for 4 weeks and then given the other regimen for another 4 weeks. There was no significant effect of potato on fasting plasma glucose, lipids, or HbA1c. There was no significant body weight increase. Diastolic blood pressure significantly decreased 4.3%, a 4 mm reduction. Systolic blood pressure decreased 3.5%, a 5 mm reduction. This blood pressure drop occurred despite the fact that 14 of 18 subjects were taking antihypertensive drugs. This is the first study to investigate the effect of potatoes on blood pressure. Thus, purple potatoes are an effective hypotensive agent and lower the risk of heart disease and stroke in hypertensive subjects without weight gain.

Atherosclerosis and oxidant stress: the end of the road for antioxidant vitamin treatment?

Extensive experimental data have revealed a central role for oxidative stress in atherogenesis and suggested a potential role for 'antioxidant' treatment in cardiovascular disease (CVD) [1-11]. Experimental data, however, have not translated into clinical benefit: most antioxidant vitamin trials have failed to reduce cardiovascular morbidity and mortality [12]. Moreover, recent clinical trials have suggested that mono-therapy with certain antioxidant vitamins like vitamin E may, in fact, be detrimental [13]. As a result of the disappointing outcome of 'antioxidant' vitamin trials, some authors have questioned both the utility of 'antioxidant' treatment in CVD and the supposedly central role of oxidative stress in atherogenesis [14-19]. Other investigators, however, sustain that the beneficial effects of lipid lowering and anti-hypertensive treatment are at least, in part, due to their 'antioxidant' properties, in addition to their specific pharmacological properties [20, 21]. Oxidant stress plays a pivotal role in atherogenesis, however, the clinical promise of antioxidant vitamins has failed to translate into clinical benefit. Increasing evidence suggests that more rigorous clinical trial designs are necessary to effectively divulge antioxidant utility and that a multifaceted antioxidant approach to atherosclerosis may yield the most clinical reward. This article reviews currently available evidence on the role of oxidant stress in atherosclerosis, analyzes the results of large anti-oxidant trials, and suggests ways to investigate the true role of antioxidant treatment in the clinical setting.

Insights into the beneficial effect of caloric/ dietary restriction for a healthy and prolonged life

Over the last several years, new evidence has kept pouring in about the remarkable effect of caloric restriction (CR) on the conspicuous bedfellows- aging and cancer. Through the use of various animal models, it is now well established that by reducing calorie intake one can not only increase life span but, also, lower the risk of various age related diseases such as cancer. Cancer cells are believed to be more dependent on glycolysis for their energy requirements than normal cells and, therefore, can be easily targeted by alteration in the energy-metabolic pathways, a hallmark of CR. Apart from inhibiting the growth of transplantable tumors, CR has been also shown to inhibit the development of spontaneous, radiation, and chemically induced tumors. The question regarding the potentiality of the anti-tumor effect of CR in humans has been in part answered by the resistance of a cohort of women, who had suffered from anorexia in their early life, to breast cancer. However, human research on the beneficial effect of CR is still at an early stage and needs further validation. Though the complete mechanism of the anti-tumor effect of CR is far from clear, the plausible involvement of nutrient sensing pathways or IGF-1 pathways proposed for its anti-aging action cannot be overruled. In fact, cancer cell lines, mutant for proteins involved in IGF-1 pathways, failed to respond to CR. In addition, CR decreases the levels of many growth factors, anabolic hormones, inflammatory cytokines, and oxidative markers that are deregulated in several cancers. In this review, we discuss the anti-tumor effect of CR, describing experiments done in vitro in tumor models and in vivo in mouse models in which the tumor was induced by means of radiation or chemical exposure, expressing oncogenes or deleting tumor suppression genes. We also discuss the proposed mechanisms of CR anti-tumor action. Lastly, we argue the necessity of gene expression studies in cancerous versus normal cells upon CR.

Bioavailability of herbs and spices in humans as determined by ex vivo inflammatory suppression and DNA strand breaks.

OBJECTIVE: The aim of this work was to determine the bioavailability of herbs and spices after human consumption by measuring the ability to protect lymphocytes from an oxidative injury and by examining the impact on inflammatory biomarkers in activated THP-1 cells. METHODS: Ten to 12 subjects in each of 13 groups consumed a defined amount of herb or spice for 7 days. Blood was drawn from subjects before consumption and 1 hour after taking the final herb or spice capsules. Subject serum and various extractions of the herbs and spices were analyzed for antioxidant capacity by oxygen radical absorbance capacity (ORAC) analysis or by 1,1-diphenyl-2-picrylhydrzyl (DPPH). Subject peripheral blood mononuclear cells (PBMCs) in medium with10% autologous serum were incubated with hydrogen peroxide to induce DNA strand breaks. Subject serum was also used to treat activated THP-1 cells to determine relative quantities of 3 inflammatory cytokine (tumor necrosis factor-α [TNF-α], interleukin-1α [IL-1α], and IL-6) mRNAs. RESULTS: Herbs and spices that protected PBMCs against DNA strand breaks were paprika, rosemary, ginger, heat-treated turmeric, sage, and cumin. Paprika also appeared to protect cells from normal apoptotic processes. Of the 3 cytokine mRNAs studied (TNF-α, IL-1α, and IL-6), TNF-α was the most sensitive responder to oxidized LDL-treated macrophages. Clove, ginger, rosemary, and turmeric were able to significantly reduce oxidized LDL-induced expression of TNF-α. Serum from those consuming ginger reduced all three inflammatory biomarkers. Ginger, rosemary, and turmeric showed protective capacity by both oxidative protection and inflammation measures. CONCLUSIONS: DNA strand breaks and inflammatory biomarkers are a good functional measure of a food's bioavailability.

Mitochondrial and nuclear DNA damage induced by curcumin in human hepatoma G2 cells.

Curcumin is extensively used as a spice and pigment and has anticarcinogenic effects that could be linked to its antioxidant properties. However, some studies suggest that this natural compound possesses both pro- and antioxidative effects. In this study, we found that curcumin induced DNA damage to both the mitochondrial and nuclear genomes in human hepatoma G2 cells. Using quantitative polymerase chain reaction and immunocytochemistry staining of 8-hydroxydeoxyguanosine, we demonstrated that curcumin induced dose-dependent damage in both the mitochondrial and nuclear genomes and that the mitochondrial damage was more extensive. Nuclear DNA fragments were also evident in comet assays. The mechanism underlies the elevated level of reactive oxygen species and lipid peroxidation generated by curcumin. The lack of DNA damage at low doses suggested that low levels of curcumin does not induce DNA damage and may play an antioxidant role in carcinogenesis. But at high doses, we found that curcumin imposed oxidative stress and damaged DNA. These data reinforce the hypothesis that curcumin plays a conflicting dual role in carcinogenesis. Also, the extensive mitochondrial DNA damage might be an initial event triggering curcumin-induced cell death.

Hazelnut-enriched diet improves cardiovascular risk biomarkers beyond a lipid-lowering effect in hypercholesterolemic subjects.

BACKGROUND: Tree nuts, particularly almonds, walnuts, and pistachios, have been shown to possess cardioprotective effects. However, there is little information on the effects of hazelnut consumption on cardiovascular risk markers. METHODS: The antiatherogenic effect of hazelnut before and after consumption in hypercholesterolemic subjects was investigated. Twenty-one hypercholesterolemic volunteers (18 men and 3 women) were recruited in a double control sandwich model intervention study with a single group and three isoenergetic diet periods. These were control diet I (4 weeks), hazelnut-enriched diet (4 weeks; hazelnut contributing 18%-20% of the total daily energy intake), and control diet period II (4 weeks). The cardiovascular risk biomarkers such as endothelial function, using flow-mediated dilation (FMD) technique, low-density lipoprotein (LDL) oxidation products and inflammatory markers such as high-sensitivity C-reactive protein (hs-CRP), soluble intercellular adhesion molecule-1, and soluble vascular cell adhesion molecule-1 (sVCAM-1) as well as lipids and lipoprotein levels were monitored. RESULTS: Consumption of a hazelnut-enriched diet significantly improved FMD (56.6%), total cholesterol (-7.8%), triacylglycerol (-7.3%), LDL-cholesterol (-6.17%), and high-density lipoprotein cholesterol (6.07%) compared with the control diet I. Oxidized-LDL, hs-CRP, and sVCAM-1 levels were significantly lower in the group ingesting a hazelnut-enriched diet compared with the control diets I and II. Modest correlations between sVCAM-1 and FMD and between sVCAM-1 and hs-CRP were observed (r = -0.49, P < .025; r = 0.66, P < .001, respectively). CONCLUSION: Hazelnut-enriched diets may exert antiatherogenic effect by improving endothelial function, preventing LDL oxidation, and inflammatory markers, in addition to their lipid and lipoprotein-lowering effects. These beneficial effects appeared to be reversible after 4 weeks on a hazelnut-free diet. Therefore, hazelnut may be incorporated into daily diet without change in total caloric intake for sustained health benefit. Copyright © 2013 National Lipid Association. All rights reserved.

Phytochemicals and their impact on adipose tissue inflammation and diabetes.

Type 2 diabetes mellitus is an inflammatory disease and the mechanisms that underlie this disease, although still incompletely understood, take place in the adipose tissue of obese subjects. Concurrently, the prevalence of obesity caused by Western diet's excessive energy intake and the lack of exercise escalates, and is believed to be causative for the chronic inflammatory state in adipose tissue. Overnutrition itself as an overload of energy may induce the adipocytes to secrete chemokines activating and attracting immune cells to adipose tissue. But also inflammation-mediating food ingredients like saturated fatty acids are believed to directly initiate the inflammatory cascade. In addition, hypoxia in adipose tissue as a direct consequence of obesity, and its effect on gene expression in adipocytes and surrounding cells in fat tissue of obese subjects appears to play a central role in this inflammatory response too. In contrast, revisiting diet all over the world, there are also some natural food products and beverages which are associated with curative effects on human health. Several natural compounds known as spices such as curcumin, capsaicin, and gingerol, or secondary plant metabolites catechin, resveratrol, genistein, and quercetin have been reported to provide an improved health status to their consumers, especially with regard to diabetes, and therefore have been investigated for their anti-inflammatory effect. In this review, we will give an overview about these phytochemicals and their role to interfere with inflammatory cascades in adipose tissue and their potential for fighting against inflammatory diseases like diabetes as investigated in vivo. Copyright © 2012 Elsevier Inc. All rights reserved.

Several culinary and medicinal herbs are important sources of dietary antioxidants.

We assessed the contribution of culinary and medicinal herbs to the total intake of dietary antioxidants. Our results demonstrate that there is more than a 1000-fold difference among antioxidant concentrations of various herbs. Of the dried culinary herbs tested, oregano, sage, peppermint, garden thyme, lemon balm, clove, allspice and cinnamon as well as the Chinese medicinal herbs Cinnamomi cortex and Scutellariae radix all contained very high concentrations of antioxidants (i.e., >75 mmol/100 g). In a normal diet, intake of herbs may therefore contribute significantly to the total intake of plant antioxidants, and be an even better source of dietary antioxidants than many other food groups such as fruits, berries, cereals and vegetables. In addition, the herbal drug, Stronger Neo-Minophagen C, a glycyrrhizin preparation used as an intravenous injection for the treatment of chronic hepatitis, boosts total antioxidant intake. It is tempting to speculate that several of the effects due to these herbs are mediated by their antioxidant activities.

Manipulating antioxidant intake in asthma: a randomized controlled trial.

BACKGROUND: Antioxidant-rich diets are associated with reduced asthma prevalence in epidemiologic studies. We previously showed that short-term manipulation of antioxidant defenses leads to changes in asthma outcomes. OBJECTIVE: The objective was to investigate the effects of a high-antioxidant diet compared with those of a low-antioxidant diet, with or without lycopene supplementation, in asthma. DESIGN: Asthmatic adults (n = 137) were randomly assigned to a high-antioxidant diet (5 servings of vegetables and 2 servings of fruit daily; n = 46) or a low-antioxidant diet (≤2 servings of vegetables and 1 serving of fruit daily; n = 91) for 14 d and then commenced a parallel, randomized, controlled supplementation trial. Subjects who consumed the high-antioxidant diet received placebo. Subjects who consumed the low-antioxidant diet received placebo or tomato extract (45 mg lycopene/d). The intervention continued until week 14 or until an exacerbation occurred. RESULTS: After 14 d, subjects consuming the low-antioxidant diet had a lower percentage predicted forced expiratory volume in 1 s and percentage predicted forced vital capacity than did those consuming the high-antioxidant diet. Subjects in the low-antioxidant diet group had increased plasma C-reactive protein at week 14. At the end of the trial, time to exacerbation was greater in the high-antioxidant than in the low-antioxidant diet group, and the low-antioxidant diet group was 2.26 (95% CI: 1.04, 4.91; P = 0.039) times as likely to exacerbate. Of the subjects in the low-antioxidant diet group, no difference in airway or systemic inflammation or clinical outcomes was observed between the groups that consumed the tomato extract and those who consumed placebo. CONCLUSIONS: Modifying the dietary intake of carotenoids alters clinical asthma outcomes. Improvements were evident only after increased fruit and vegetable intake, which suggests that whole-food interventions are most effective. This trial was registered at http://www.actr.org.au as ACTRN012606000286549.

Anti-proliferative activity and chemoprotective effects towards DNA oxidative damage of fresh and cooked Brassicaceae.

Epidemiological evidence shows that regular consumption of Brassicaceae is associated with a reduced risk of cancer and heart disease. Cruciferous species are usually processed before eating and the real impact of cooking practices on their bioactive properties is not fully understood. We have evaluated the effect of common cooking practices (boiling, microwaving, and steaming) on the biological activities of broccoli, cauliflower and Brussels sprouts. Anti-proliferative and chemoprotective effects towards DNA oxidative damage of fresh and cooked vegetable extracts were evaluated by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium and Comet assays on HT-29 human colon carcinoma cells. The fresh vegetable extracts showed the highest anti-proliferative and antioxidant activities on HT-29 cells (broccoli>cauliflower = Brussels sprouts). No genotoxic activity was detected in any of the samples tested. The cooking methods that were applied influenced the anti-proliferative activity of Brassica extracts but did not alter considerably the antioxidant activity presented by the raw vegetables. Raw, microwaved, boiled (except broccoli) and steamed vegetable extracts, at different concentrations, presented a protective antioxidative action comparable with vitamin C (1 mm). These data provide new insight into the influence of domestic treatment on the quality of food, which could support the recent epidemiological studies suggesting that consumption of cruciferous vegetables, mainly cooked, may be related to a reduced risk of developing cancer.

Black pepper and its pungent principle-piperine: a review of diverse physiological effects.

Black pepper (Piper nigrum) is one of the most widely used among spices. It is valued for its distinct biting quality attributed to the alkaloid, piperine. Black pepper is used not only in human dietaries but also for a variety of other purposes such as medicinal, as a preservative, and in perfumery. Many physiological effects of black pepper, its extracts, or its major active principle, piperine, have been reported in recent decades. Dietary piperine, by favorably stimulating the digestive enzymes of pancreas, enhances the digestive capacity and significantly reduces the gastrointestinal food transit time. Piperine has been demonstrated in in vitro studies to protect against oxidative damage by inhibiting or quenching free radicals and reactive oxygen species. Black pepper or piperine treatment has also been evidenced to lower lipid peroxidation in vivo and beneficially influence cellular thiol status, antioxidant molecules and antioxidant enzymes in a number of experimental situations of oxidative stress. The most far-reaching attribute of piperine has been its inhibitory influence on enzymatic drug biotransforming reactions in the liver. It strongly inhibits hepatic and intestinal aryl hydrocarbon hydroxylase and UDP-glucuronyl transferase. Piperine has been documented to enhance the bioavailability of a number of therapeutic drugs as well as phytochemicals by this very property. Piperine's bioavailability enhancing property is also partly attributed to increased absorption as a result of its effect on the ultrastructure of intestinal brush border. Although initially there were a few controversial reports regarding its safety as a food additive, such evidence has been questionable, and later studies have established the safety of black pepper or its active principle, piperine, in several animal studies. Piperine, while it is non-genotoxic, has in fact been found to possess anti-mutagenic and anti-tumor influences.

Relationship of dietary fat to glucose metabolism.

The relationship between dietary fat and glucose metabolism has been recognized for at least 60 years. In experimental animals, high fat diets result in impaired glucose tolerance. This impairment is associated with decreased basal and insulin-stimulated glucose metabolism. Impaired insulin binding and/or glucose transporters has been related to changes in the fatty acid composition of the membrane induced by dietary fat modification. In humans, high-fat diets, independent of fatty acid profile, have been reported to result in decreased insulin sensitivity. Saturated fat, relative to monounsaturated and polyunsaturated fat, appears to be more deleterious with respect to fat-induced insulin insensitivity. Some of the adverse effects induced by fat feeding can be ameliorated with omega-3 fatty acid. Epidemiological data in humans suggest that subjects with higher intakes of fat are more prone to develop disturbances in glucose metabolism, type 2 diabetes or impaired glucose tolerance, than subjects with lower intakes of fat. Inconsistencies in the data may be attributable to clustering of high intakes of dietary fat (especially animal fat) with obesity and inactivity. Metabolic studies suggest that higher-fat diets containing a higher proportion of unsaturated fat result in better measures of glucose metabolism than high-carbohydrate diet. Clearly, the area of dietary fat and glucose metabolism has yet to be fully elucidated.

Multitargeting by turmeric, the golden spice: From kitchen to clinic.

Although much has been published about curcumin, which is obtained from turmeric, comparatively little is known about turmeric itself. Turmeric, a golden spice obtained from the rhizome of the plant Curcuma longa, has been used to give color and taste to food preparations since ancient times. Traditionally, this spice has been used in Ayurveda and folk medicine for the treatment of such ailments as gynecological problems, gastric problems, hepatic disorders, infectious diseases, and blood disorders. Modern science has provided the scientific basis for the use of turmeric against such disorders. Various chemical constituents have been isolated from this spice, including polyphenols, sesquiterpenes, diterpenes, triterpenoids, sterols, and alkaloids. Curcumin, which constitutes 2-5% of turmeric, is perhaps the most-studied component. Although some of the activities of turmeric can be mimicked by curcumin, other activities are curcumin-independent. Cell-based studies have demonstrated the potential of turmeric as an antimicrobial, insecticidal, larvicidal, antimutagenic, radioprotector, and anticancer agent. Numerous animal studies have shown the potential of this spice against proinflammatory diseases, cancer, neurodegenerative diseases, depression, diabetes, obesity, and atherosclerosis. At the molecular level, this spice has been shown to modulate numerous cell-signaling pathways. In clinical trials, turmeric has shown efficacy against numerous human ailments including lupus nephritis, cancer, diabetes, irritable bowel syndrome, acne, and fibrosis. Thus, a spice originally common in the kitchen is now exhibiting activities in the clinic. In this review, we discuss the chemical constituents of turmeric, its biological activities, its molecular targets, and its potential in the clinic. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of spiced food on metabolic rate.

Since the time of Lavoisier it has been known that the ingestion of food in animals and man produces an increase in oxygen consumption. This increase in metabolic rate was originally called 'specific dynamic action' (SDA) and is now widely referred to as the thermic effect (TE) of food or diet-induced thermogenesis (DIT) (Rothwell & Stock, 1981). Much of the early work on the thermic effect was confined to the type and amount of food, notably the macronutrients--proteins, fats and carbohydrates. Later, it was shown that certain minor constituents of the diet such as caffeine and associated methylxanthines (Zahorska-Markrewicz, 1980; Jung et al., 1981) in tea and coffee could also have a profound effect on metabolic rate. The consumption of alcohol was also shown to increase metabolic rate (Rosenberg & Durnin, 1978). The work described in this paper reports the effect of another minor constituent of food, spices, on metabolic rate. Although the use of spices in our food has steadily increased with time little information exists on their effect on the metabolic rate. It has been estimated that approximately 40 different spices are used in our diet today. This communication reports the effect of chilli (red pepper, capsicum annuum) and mustard (Brassica juncea).

Antioxidant, antimutagenic, and antitumor effects of pine needles (Pinus densiflora).

Pine needles (Pinus densiflora Siebold et Zuccarini) have long been used as a traditional health-promoting medicinal food in Korea. To investigate their potential anticancer effects, antioxidant, antimutagenic, and antitumor activities were assessed in vitro and/or in vivo. Pine needle ethanol extract (PNE) significantly inhibited Fe(2+)-induced lipid peroxidation and scavenged 1,1-diphenyl- 2-picrylhydrazyl radical in vitro. PNE markedly inhibited mutagenicity of 2-anthramine, 2-nitrofluorene, or sodium azide in Salmonella typhimurium TA98 or TA100 in Ames tests. PNE exposure effectively inhibited the growth of cancer cells (MCF-7, SNU-638, and HL-60) compared with normal cell (HDF) in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. In in vivo antitumor studies, freeze-dried pine needle powder supplemented (5%, wt/wt) diet was fed to mice inoculated with Sarcoma-180 cells or rats treated with mammary carcinogen, 7,12-dimethylbenz[a]anthracene (DMBA, 50 mg/kg body weight). Tumorigenesis was suppressed by pine needle supplementation in the two model systems. Moreover, blood urea nitrogen and aspartate aminotransferase levels were significantly lower in pine needle-supplemented rats in the DMBA-induced mammary tumor model. These results demonstrate that pine needles exhibit strong antioxidant, antimutagenic, and antiproliferative effects on cancer cells and also antitumor effects in vivo and point to their potential usefulness in cancer prevention.

Vegetarian diets and public health: biomarker and redox connections.

Vegetarian diets are rich in antioxidant phytochemicals. However, they may not act as antioxidants in vivo, and yet still have important signaling and regulatory functions. Some may act as pro-oxidants, modulating cellular redox tone and oxidizing redox sensitive sites. In this review, evidence for health benefits of vegetarian diets is presented from different perspectives: epidemiological, biomarker, evolutionary, and public health, as well as antioxidant. From the perspective of molecular connections between diet and health, evidence of a role for plasma ascorbic acid as a biomarker for future disease risk is presented. Basic concepts of redox-based cell signaling are presented, and effects of antioxidant phytochemicals on signaling, especially via redox tone, sulfur switches and the Antioxidant Response Element (ARE), are explored. Sufficient scientific evidence exists for public health policy to promote a plant-rich diet for health promotion. This does not need to wait for science to provide all the answers as to why and how. However, action and interplay of dietary antioxidants in the nonequilibrium systems that control redox balance, cell signaling, and cell function provide rich ground for research to advance understanding of orthomolecular nutrition and provide science-based evidence to advance public health in our aging population.

Consumption of eggs with meals increases the susceptibility of human plasma and low-density lipoprotein to lipid peroxidation.

Consumption of eggs for a long period was shown to result in hypercholesterolemia and is generally restricted for this reason. In the present study we analyzed the effect of eggs consumption for 3 weeks on lipoprotein atherogenicity. Consumption of 2 eggs per day with the meals, for 3 weeks resulted in a minor elevation in plasma glucose and urea concentrations. Plasma cholesterol concentration increased by 11% (p < 0.05) as a result of increased plasma low-density lipoprotein (LDL) cholesterol levels. Plasma triglycerides decreased by 13% (p < 0.01), but there were no significant alterations in plasma apolipoproteins A-I or B-100 concentrations. Plasma high-density lipoprotein (HDL) cholesterol decreased by 11% (p < 0.05). There was a 13% reduction, though not significant, in the cholesterol efflux from J-774 A.1 macrophages by HDL that was derived after eggs consumption in comparison to HDL that was obtained at baseline. The susceptibility of plasma [using 100 mM of 2,2' azobis 2-amidinopropane (AAPH)] as well as that of LDL (using 10 microM of copper ions) to lipid peroxidation was increased by 42% and 34%, respectively, as measured by the thiobarbituric acid reactive substance (TBARS) assay (p < 0.01). Kinetic analysis of LDL oxidation by copper ions revealed a 37% reduction in the lag time required for the initiation of LDL oxidation after 3 weeks of eggs consumption. The total plasma fatty acids concentration increased from 2.2 +/- 0.5 to 3.2 +/- 0.6 mg/ml. The plasma antioxidants, vitamin E and carotenoids were not significantly affected by eggs consumption. We conclude that eggs consumption, in addition to its hypercholesterolemic effect, increases plasma and LDL oxidizability, a phenomenon which was shown to enhance the progression of atherosclerosis. The atherogenic properties may contribute to the accelerated atherosclerosis prevalent in populations with high cholesterol intake.

Antioxidant supplements for prevention of gastrointestinal cancers: a systematic review and meta-analysis.

BACKGROUND: Oxidative stress can cause cancer. Our aim was to establish whether antioxidant supplements reduce the incidence of gastrointestinal cancer and mortality. METHODS: With the Cochrane Collaboration methodology, we reviewed all randomised trials comparing antioxidant supplements with placebo for prevention of gastrointestinal cancers. We searched electronic databases and reference lists (February, 2003). Outcome measures were incidence of gastrointestinal cancers, overall mortality, and adverse effects. Outcomes were analysed with fixed-effect and random-effects model meta-analyses and were reported as relative risk with 95% CIs. FINDINGS: We identified 14 randomised trials (n=170,525). Trial quality was generally high. Heterogeneity of results was low to moderate. Neither the fixed-effect (relative risk 0.96, 95% CI 0.88-1.04) nor random-effects meta-analyses (0.90, 0.77-1.05) showed significant effects of supplementation with beta-carotene, vitamins A, C, E, and selenium (alone or in combination) versus placebo on oesophageal, gastric, colorectal, pancreatic, and liver cancer incidences. In seven high-quality trials (n=131727), the fixed-effect model showed that antioxidant significantly increased mortality (1.06, 1.02-1.10), unlike the random-effects meta-analysis (1.06, 0.98-1.15). Low-quality trials showed no significant effect of antioxidant supplementation on mortality. The difference between the mortality estimates in high-quality and low-quality trials was significant (Z=2.10, p=0.04 by test of interaction). beta-carotene and vitamin A (1.29, 1.14-1.45) and beta-carotene and vitamin E (1.10, 1.01-1.20) significantly increased mortality, whereas beta-carotene alone only tended to increase mortality (1.05, 0.99-1.11). In four trials (three with unclear or inadequate methodology), selenium showed significant beneficial effect on the incidence of gastrointestinal cancer. INTERPRETATION: We could not find evidence that antioxidant supplements can prevent gastrointestinal cancers; on the contrary, they seem to increase overall mortality. The potential preventive effect of selenium should be studied in adequate randomised trials.

Effects of tomato extract on human platelet aggregation in vitro.

Among all fruits tested in vitro for their anti-platelet property, tomato had the highest activity followed by grapefruit, melon, and strawberry, whereas pear and apple had little or no activity. Tomato extract (20-50 microl of 100% juice) inhibited both ADP- and collagen-induced aggregation by up to 70% but could not inhibit arachidonic acid-induced platelet aggregation and concomitant thromboxane synthesis under similar experimental conditions. The anti-platelet components (MW <1000 Da) in tomatoes are water soluble, heat stable and are concentrated in the yellow fluid around the seeds. The active fractions were separated using gel filtration and HPLC. The aqueous fraction (110 000 xg supernatant) of tomatoes containing anti-platelet activity was subjected to gel filtration column chromatography (Biogel P2 column). The activity was fractionated into two peaks, peak-3 and peak-4 (major peak). Subsequently, peak-4 was further purified by HPLC using a reversed-phase column. NMR and mass spectroscopy studies indicated that peak F2 (obtained from peak 4) contained adenosine and cytidine. Deamination of peak F2 with adenosine deaminase almost completely abolished its anti-platelet activity, confirming the presence of adenosine in this fraction. In comparison, deamination of peak-4 resulted in only partial loss of inhibitory activity while the activity of peak-3 remained unaffected. These results indicate that tomatoes contain anti-platelet compounds in addition to adenosine. Unlike aspirin, the tomato-derived compounds inhibit thrombin-induced platelet aggregation. All these data indicate that tomato contains very potent anti-platelet components, and consuming tomatoes might be beneficial both as a preventive and therapeutic regime for cardiovascular disease.

Evolution of dietary antioxidants.

Oxygen is vital for most organisms but, paradoxically, damages key biological sites. Oxygenic threat is met by antioxidants that evolved in parallel with our oxygenic atmosphere. Plants employ antioxidants to defend their structures against reactive oxygen species (ROS; oxidants) produced during photosynthesis. The human body is exposed to these same oxidants, and we have also evolved an effective antioxidant system. However, this is not infallible. ROS breach defences, oxidative damage ensues, accumulates with age, and causes a variety of pathological changes. Plant-based, antioxidant-rich foods traditionally formed the major part of the human diet, and plant-based dietary antioxidants are hypothesized to have an important role in maintaining human health. This hypothesis is logical in evolutionary terms, especially when we consider the relatively hypoxic environment in which humans may have evolved. In this paper, the human diet is discussed briefly in terms of its evolutionary development, different strategies of antioxidant defence are outlined, and evolution of dietary antioxidants is discussed from the perspectives of plant need and our current dietary requirements. Finally, possibilities in regard to dietary antioxidants, evolution, and human health are presented, and an evolutionary cost-benefit analysis is presented in relation to why we lost the ability to make ascorbic acid (vitamin C) although we retained an absolute requirement for it.

Resolving the Coronary Artery Disease Epidemic Through Plant-Based Nutrition.

The world's advanced countries have easy access to plentiful high-fat food; ironically, it is this rich diet that produces atherosclerosis. In the world's poorer nations, many people subsist on a primarily plant-based diet, which is far healthier, especially in terms of heart disease. To treat coronary heart disease, a century of scientific investigation has produced a device-driven, risk factor-oriented strategy. Nevertheless, many patients treated with this approach experience progressive disability and death. This strategy is a rear-guard defensive one. In contrast, compelling data from nutritional studies, population surveys, and interventional studies support the effectiveness of a plant-based diet and aggressive lipid lowering to arrest, prevent, and selectively reverse heart disease. In essence, this is an offensive strategy. The single biggest step toward adopting this strategy would be to have United States dietary guidelines support a plant-based diet. An expert committee purged of industrial and political influence is required to assure that science is the basis for dietary recommendations. (c)2001 CHF, Inc.

Effects of increasing amounts of dietary cholesterol on postprandial lipemia and lipoproteins in human subjects.

Our aim was to determine the effects of increasing amounts of dietary cholesterol (0-710 mg) on the postprandial plasma lipid responses and lipoprotein changes in normolipidemic human subjects. Ten subjects were fed five different test meals in a random order: one meal did not contain fat or cholesterol while the four others contained a fixed amount of lipids (45 g) and 0, 140, 280, and 710 mg cholesterol, respectively. Fasting and post-meal blood samples were obtained for 7 h. Large and small triglyceride-rich lipoproteins (TRL), low density (LDL), and high density (HDL) lipoproteins were isolated. Compared to the no-fat, no-cholesterol meal, the fat-enriched meals raised (P < 0.05) plasma triglycerides, phospholipids, and free cholesterol and lowered cholesteryl esters postprandially. The meals containing zero or 140 mg cholesterol generally elicited comparable postprandial plasma and lipoprotein lipid responses. The meals providing 280 or 710 mg cholesterol significantly increased postprandial plasma phospholipids and large TRL triglycerides and decreased plasma esterified cholesterol. The lipid composition of the large TRLs and the concentrations of the small TRL lipid components were not altered postprandially by cholesterol intake. On the other hand, LDL free cholesterol increased after 3 h, LDL cholesteryl esters dropped after 3 and 7 h, HDL cholesteryl esters dropped after 3 h, and HDL phospholipids increased 7 h after ingesting meals highly enriched in cholesterol. Blood insulin, apoA-I and apoB were not altered postprandially by cholesterol intake. Thus, the data show that ingesting more than 140 mg cholesterol per meal significantly alters the postprandial lipoprotein response in healthy subjects.

Role of antioxidants in cancer therapy.

Oxidative stress is a key component in linking environmental toxicity to the multistage carcinogenic process. Reactive oxygen species (ROS) are generated in response to both endogenous and exogenous stimuli. To counterbalance ROS-mediated injury, an endogenous antioxidants defense system exists; however, when oxidation exceeds the control mechanisms, oxidative stress arises. Chronic and cumulative oxidative stress induces deleterious modifications to a variety of macromolecular components, such as DNA, lipids, and proteins. A primary mechanism of many chemotherapy drugs against cancer cells is the formation of ROS, or free radicals. Radiotherapy is based on the fact that ionizing radiation destroys tumor cells. Radiotherapy induces direct lesions in the DNA or biological molecules, which eventually affect DNA. Free radicals produced by oncology therapy are often a source of serious side effects as well. The objective of this review is to provide information about the effects of antioxidants during oncology treatments and to discuss the possible events and efficacy. Much debate has arisen about whether antioxidant supplementation alters the efficacy of cancer chemotherapy. There is still limited evidence in both quality and sample size, suggesting that certain antioxidant supplements may reduce adverse reactions and toxicities. Significant reductions in toxicity may alleviate dose-limiting toxicities so that more patients are able to complete prescribed chemotherapy regimens and thus, in turn, improve the potential for success in terms of tumor response and survival. Copyright © 2013 Elsevier Inc. All rights reserved.

Effect of dietary patterns on measures of lipid peroxidation: results from a randomized clinical trial.

BACKGROUND: Free radical-mediated oxidative damage to lipids is thought to be an important process in the pathogenesis of atherosclerosis. Although previous studies have demonstrated a beneficial impact of antioxidant vitamin supplements on lipid peroxidation, the effect of dietary patterns on lipid peroxidation is unknown. METHODS AND RESULTS: During the 3-week run-in period of a randomized trial, 123 healthy individuals were fed a control diet, low in fruits, vegetables, and dairy products, with 37% of calories from fat. Participants were then randomized to consume for 8 weeks: (1) the control diet, (2) a diet rich in fruits and vegetables but otherwise similar to the control diet, and (3) a combination diet rich in fruits, vegetables, and low-fat dairy products and reduced in fat. Serum oxygen radical-absorbing capacity, malondialdehyde (an in vitro measure of lipid peroxidation), and breath ethane (an in vivo measure of lipid peroxidation) were measured at the end of run-in and intervention periods. Between run-in and intervention, mean (95% CI) change in oxygen radical-absorbing capacity (U/mL) was -35 (-93, 13) in the control diet, 26 (-15, 67) in the fruits and vegetables diet (P=0.06 compared with control), and 19 (-22, 54) in the combination diet (P=0.10 compared with control). Median (interquartile range) change in ethane was 0.84 (0.10, 1.59) in the control diet, 0.02 (-0.61, 0.83) in the fruits and vegetables diet (P=0.04 compared with control), and -1.00 (-1.97, 0.25) in the combination diet (P=0.005 compared with control). Change in malondialdehyde did not differ between diets. CONCLUSIONS: This study demonstrates that modification of diet can favorably affect serum antioxidant capacity and protect against lipid peroxidation.

Effects of Açai (Euterpe oleracea Mart.) berry preparation on metabolic parameters in a healthy overweight population: A pilot study

Background The purpose of this study was to evaluate the effect of açai fruit pulp on risk factors for metabolic disorders in overweight subjects. The açaí palm (Euterpe oleracea Mart.), which is native to South America, produces a small, black-purple fruit which is edible. The fruit has recently become popular as a functional food due to its antioxidant potential. Although several studies have been conducted in vitro and with animals, little is known about the potential health benefits in humans aside from an increase in plasma anti-oxidant capacity. Metabolic syndrome is a condition which is defined by a cluster of risk factors for cardiovascular disease and/or type-2 diabetes. Preliminary studies indicate that a reduction in reactive oxygen species can assist in the normalization of the metabolic pathways involved in this syndrome. Methods This was an open label pilot study conducted with 10 overweight adults (BMI ≥ 25 kg/m2 and ≤ 30 kg/m2) who took 100 g açai pulp twice daily for 1 month. The study endpoints included levels of fasting plasma glucose, insulin, cholesterol, triglycerides, exhaled (breath) nitric oxide metabolites (eNO) and plasma levels of high sensitivity C-reactive protein (hs-CRP). The response of blood glucose, blood pressure and eNO to a standardized meal was determined at baseline and following the 30 day treatment. Results Compared to baseline, there were reductions in fasting glucose and insulin levels following the 30 day treatment (both p < 0.02). There was also a reduction in total cholesterol (p = 0.03), as well as borderline significant reductions in LDL-cholesterol and the ratio of total cholesterol to HDL-cholesterol (both p = 0.051). Compared to baseline, treatment with açai ameliorated the post-prandial increase in plasma glucose following the standardized meal, measured as the area under the curve (p = 0.047). There was no effect on blood pressure, hs-CRP or eNO. Conclusion In this uncontrolled pilot study, consumption of açai fruit pulp reduced levels of selected markers of metabolic disease risk in overweight adults, indicating that further studies are warranted.

Curcumin and cancer: an "old-age" disease with an "age-old" solution.

Cancer is primarily a disease of old age, and that life style plays a major role in the development of most cancers is now well recognized. While plant-based formulations have been used to treat cancer for centuries, current treatments usually involve poisonous mustard gas, chemotherapy, radiation, and targeted therapies. While traditional plant-derived medicines are safe, what are the active principles in them and how do they mediate their effects against cancer is perhaps best illustrated by curcumin, a derivative of turmeric used for centuries to treat a wide variety of inflammatory conditions. Curcumin is a diferuloylmethane derived from the Indian spice, turmeric (popularly called "curry powder") that has been shown to interfere with multiple cell signaling pathways, including cell cycle (cyclin D1 and cyclin E), apoptosis (activation of caspases and down-regulation of antiapoptotic gene products), proliferation (HER-2, EGFR, and AP-1), survival (PI3K/AKT pathway), invasion (MMP-9 and adhesion molecules), angiogenesis (VEGF), metastasis (CXCR-4) and inflammation (NF-kappaB, TNF, IL-6, IL-1, COX-2, and 5-LOX). The activity of curcumin reported against leukemia and lymphoma, gastrointestinal cancers, genitourinary cancers, breast cancer, ovarian cancer, head and neck squamous cell carcinoma, lung cancer, melanoma, neurological cancers, and sarcoma reflects its ability to affect multiple targets. Thus an "old-age" disease such as cancer requires an "age-old" treatment.

Anti-aromatase chemicals in red wine.

Estrogen synthesized in situ plays a more important role in breast cancer cell proliferation than does circulating estrogen. Aromatase is the enzyme that converts androgen to estrogen and is expressed at a higher level in breast cancer tissue than in surrounding noncancer tissue. A promising route of chemoprevention against breast cancer may be through the suppression of in situ estrogen formation using aromatase inhibitors. A diet high in fruits and vegetables may reduce the incidence of breast cancer, because they contain phytochemicals that can act as aromatase inhibitors. In our previous studies, we found that grapes and wine contain potent phytochemicals that can inhibit aromatase. We show that red wine was more effective than white wine in suppressing aromatase activity. Interestingly, our results from white wine studies suggest a weak inductive effect of alcohol on aromatase activity. On the other hand, the potent effect of anti-aromatase chemicals in red wine overcomes the weak inductive effect of alcohol in wine. Several purification procedures were performed on whole red wine to separate active aromatase inhibitors from non-active compounds. These techniques included liquid-liquid extraction, silica gel chromatography, various solid phase extraction (SPE) columns, and high performance liquid chromatography. An active Pinot Noir red wine SPE C18 column fraction (20% acetonitrile:water) was more effective than complete Pinot Noir wine in suppressing aromatase assay. This red wine extract was further analyzed in a transgenic mouse model in which aromatase was over-expressed in mammary tissue. Our gavaged red wine extract completely abrogated aromatase-induced hyperplasia and other neoplastic changes in mammary tissue. These results suggest that red wine or red wine extract may be a chemopreventive diet supplement for postmenopausal women who have a high risk of breast cancer. Further research is underway to purify and characterize the active compounds in red wine that are responsible for the inhibition of aromatase.

Evidence for a human-specific mechanism for diet and antibody-mediated inflammation in carcinoma progression

Patients with cancer have circulating heterophile antibodies that agglutinate animal red cells via recognition of the mammalian cell surface sialic acid N-glycolylneuraminic acid (Neu5Gc), which was long considered an oncofetal antigen in humans. However, humans are genetically deficient in Neu5Gc production and instead metabolically accumulate Neu5Gc from dietary sources, particularly red meats and milk products. Moreover, mice with a human-like defect showed no alternate pathway for Neu5Gc synthesis and even normal humans express anti-Neu5Gc antibodies. We show here that human tumors accumulate Neu5Gc that is covalently attached to multiple classes of glycans. The paradox of human tumor Neu5Gc accumulation in the face of circulating anti-Neu5Gc antibodies was hypothesized to be due to facilitation of tumor progression by the resulting low-grade chronic inflammation. Indeed, murine tumors expressing human-like levels of Neu5Gc show accelerated growth in syngeneic mice with a human-like Neu5Gc deficiency, coincident with the induction of anti-Neu5Gc antibodies and increased infiltration of inflammatory cells. Transfer of polyclonal monospecific syngeneic mouse anti-Neu5Gc serum also enhanced growth of transplanted syngeneic tumors bearing human-like levels of Neu5Gc, with tumors showing evidence for antibody deposition, enhanced angiogenesis and chronic inflammation. These effects were suppressed by a cyclooxygenase-2 inhibitor, a drug type known to reduce human carcinoma risk. Finally, affinity-purified human anti-Neu5Gc antibodies also accelerate growth of Neu5Gc-containing tumors in Neu5Gc-deficient mice. Taken together, the data suggest that the human propensity to develop diet-related carcinomas is contributed to by local chronic inflammation, resulting from interaction of metabolically-accumulated dietary Neu5Gc with circulating anti-Neu5Gc antibodies.

Chronic effects of a high-fat diet enriched with virgin olive oil and a low-fat diet enriched with alpha-linolenic acid on postprandial endothelial...

Traditional cardiovascular risk factors are associated with endothelial dysfunction. The vascular endothelium plays a key role in local vascular tone regulation and can be modulated by dietary fat. We propose to determine the chronic effect of three diets with different fat compositions on postprandial endothelial function and inflammatory biomarkers. Twenty healthy men followed three 4-week diets in a randomised cross-over design: a Western diet, rich in saturated fat (22% SFA, 12% MUFA and 0.4% alpha-linolenic acid (ALA), all fractions are % of energy); a Mediterranean diet, rich in MUFA ( < 10 % SFA, 24 % MUFA and 0.4% ALA); a low-fat diet enriched in ALA ( < 10% SFA, 12% MUFA and 2% ALA). At the end of each dietary period all subjects underwent a postprandial study. Plasma concentrations of lipid parameters, soluble intercellular cell-adhesion molecule-1, soluble vascular cell-adhesion molecule-1 (sVCAM-1), nitrates and nitrites (NOx) and endothelial function studied by laser Doppler were examined at 0, 2, 4, 6 and 8 h. The endothelium-dependent vasodilatory response was greater 4 h after the ingestion of the MUFA-rich diet than after the SFA or ALA low-fat diets (P = 0.031). The 4 h postprandial plasma sVCAM-1 levels were lower after the MUFA meals than after the ALA low-fat diet (P = 0.043). The bioavailability of NOx was higher following the MUFA diet than after the SFA and ALA low-fat diets (P = 0.027). We found no differences in the other parameters measured. Chronic ingestion of a Mediterranean diet avoids the postprandial deterioration of endothelial function associated with Westernised diets in healthy individuals.

Impaired endothelial function following a meal rich in used cooking fat.

OBJECTIVES: The purpose of this study was to test the hypothesis that intake of used cooking fat is associated with impaired endothelial function. BACKGROUND: Diets containing high levels of lipid oxidation products may accelerate atherogenesis, but the effect on endothelial function is unknown. METHODS: Flow-mediated endothelium-dependent dilation and glyceryl trinitrate-induced endothelium-independent dilation of the brachial artery were investigated in 10 men. Subjects had arterial studies before and 4 h after three test meals: 1) a meal (fat 64.4 g) rich in cooking fat that had been used for deep frying in a fast food restaurant; 2) the same meal (fat 64.4 g) rich in unused cooking fat, and 3) a corresponding low fat meal (fat 18.4 g) without added fat. RESULTS: Endothelium-dependent dilation decreased between fasting and postprandial studies after the used fat meal (5.9 +/- 2.3% vs. 0.8 +/- 2.2%, p = 0.0003), but there was no significant change after the unused fat meal (5.3 +/- 2.1% vs. 6.0 +/- 2.5%) or low fat meal (5.3 +/- 2.3% vs. 5.4 +/- 3.3%). There was no significant difference in endothelium-independent dilation after any of the meals. Plasma free fatty acid concentration did not change significantly during any of the meals. The level of postprandial hypertriglyceridemia was not associated with change in endothelial function. CONCLUSIONS: Ingestion of a meal rich in fat previously used for deep frying in a commercial fast food restaurant resulted in impaired arterial endothelial function. These findings suggest that intake of degradation products of heated fat contribute to endothelial dysfunction.

A wholly nutritional 'multifocal angiostatic therapy' for control of disseminated cancer.

A great deal of effort is now being devoted to the development of new drugs that hopefully will control the spread of inoperable cancer by safely inhibiting tumor-evoked angiogenesis. However, there is growing evidence that certain practical nutritional measures have the potential to slow tumor angiogenesis, and it is reasonable to anticipate that, by combining several measures that work in distinct but complementary ways to impede the angiogenic process, a clinically useful 'multifocal angiostatic therapy' (MAT) might be devised. Several measures which might reasonably be included in such a protocol are discussed below, and include: a low-fat, low-glycemic index vegan diet, which may down-regulate the systemic IGF-I activity that supports angiogenesis; supplemental omega-3-rich fish oil, which has been shown to inhibit endothelial expression of Flk-1, a functionally crucial receptor for VEGF, and also can suppress tumor production of pro-angiogenic eicosanoids; high-dose selenium, which has recently been shown to inhibit tumor production of VEGF; green tea polyphenols, which can suppress endothelial responsiveness to both VEGF and fibroblast growth factor; and high-dose glycine, whose recently reported angiostatic activity may reflect inhibition of endothelial cell mitosis, possibly mediated by activation of glycine-gated chloride channels. In light of evidence that tumor-evoked angiogenesis has a high requirement for copper, copper depletion may have exceptional potential as an angiostatic measure, and is most efficiently achieved with the copper-chelating drug tetrathiomolybdate. If logistical difficulties make it difficult to acquire this experimental drug, high-dose zinc supplementation can achieve a slower depletion of the body's copper pool, and in any case can be used as maintenance therapy to maintain an adequate level of copper depletion. A provisional protocol is offered for a nutritionally based MAT entailing a vegan diet and supplemental intakes of fish oil, selenium, green tea polyphenols, glycine, and zinc. Inasmuch as cox-2 is overexpressed in many cancers, and cAMP can boost tumor production of various angiogenic factors as well as autogenous growth factors, adjunctive use of cox-2-specific NSAIDS may be warranted in some cases.

Cocoa, Blood Pressure, and Cardiovascular Health.

High blood pressure is an important risk factor for cardiovascular disease and cardiovascular events worldwide. Clinical and epidemiological studies suggest that cocoa-rich products reduce the risk of cardiovascular disease. According to this, cocoa has a high content in polyphenols, especially flavanols. Flavanols have been described to exert favorable effects on endothelium-derived vasodilation via the stimulation of nitric oxide-synthase, the increased availability of l-arginine, and the decreased degradation of NO. Cocoa may also have a beneficial effect by protecting against oxidative stress alterations and via decreased platelet aggregation, decreased lipid oxidation, and insulin resistance. These effects are associated with a decrease of blood pressure and a favorable trend toward a reduction in cardiovascular events and strokes. Previous meta-analyses have shown that cocoa-rich foods may reduce blood pressure. Long-term trials investigating the effect of cocoa products are needed to determine whether or not blood pressure is reduced on a chronic basis by daily ingestion of cocoa. Furthermore, long-term trials investigating the effect of cocoa on clinical outcomes are also needed to assess whether cocoa has an effect on cardiovascular events. A 3 mmHg systolic blood pressure reduction has been estimated to decrease the risk of cardiovascular and all-cause mortality. This paper summarizes new findings concerning cocoa effects on blood pressure and cardiovascular health, focusing on putative mechanisms of action and "nutraceutical " viewpoints.

Supplementation of a western diet with golden kiwifruits (Actinidia chinensis var.'Hort 16A':) effects on biomarkers of oxidation damage and antioxidant protection

Background The health positive effects of diets high in fruits and vegetables are generally not replicated in supplementation trials with isolated antioxidants and vitamins, and as a consequence the emphasis of chronic disease prevention has shifted to whole foods and whole food products. Methods We carried out a human intervention trial with the golden kiwifruit, Actinidia chinensis, measuring markers of antioxidant status, DNA stability, plasma lipids, and platelet aggregation. Our hypothesis was that supplementation of a normal diet with kiwifruits would have an effect on biomarkers of oxidative status. Healthy volunteers supplemented a normal diet with either one or two golden kiwifruits per day in a cross-over study lasting 2 × 4 weeks. Plasma levels of vitamin C, and carotenoids, and the ferric reducing activity of plasma (FRAP) were measured. Malondialdehyde was assessed as a biomarker of lipid oxidation. Effects on DNA damage in circulating lymphocytes were estimated using the comet assay with enzyme modification to measure specific lesions; another modification allowed estimation of DNA repair. Results Plasma vitamin C increased after supplementation as did resistance towards H2O2-induced DNA damage. Purine oxidation in lymphocyte DNA decreased significantly after one kiwifruit per day, pyrimidine oxidation decreased after two fruits per day. Neither DNA base excision nor nucleotide excision repair was influenced by kiwifruit consumption. Malondialdehyde was not affected, but plasma triglycerides decreased. Whole blood platelet aggregation was decreased by kiwifruit supplementation. Conclusion Golden kiwifruit consumption strengthens resistance towards endogenous oxidative damage.

Fat intake modulates cerebral blood flow in homeostatic and gustatory brain areas in humans.

BACKGROUND: The hypothalamus is the central homeostatic control region of the brain and, therefore, highly influenced by nutrients such as glucose and fat. Immediate and prolonged homeostatic effects of glucose ingestion have been well characterized. However, studies that used stimulation with fat have mainly investigated immediate perceptional processes. Besides homeostatic processes, the gustatory cortex, including parts of the insular cortex, is crucial for the processing of food items. OBJECTIVE: The aim of this study was to investigate the effect of high- compared with low-fat meals on the hypothalamus and the insular cortex. DESIGN: Eleven healthy men participated in a single-blinded, functional MRI study of high- and low-fat meals on 2 measurement days. Cerebral blood flow (CBF) was measured before and 30 and 120 min after intake of high- and low-fat yogurts. Hunger was rated and blood samples were taken before each CBF measurement. RESULTS: High-fat yogurt induced a pronounced decrease in CBF in the hypothalamus, and the corresponding CBF change correlated positively with the insulin change. Furthermore, insular activity increased after 120 min in the low-fat condition only. The CBF change in both regions correlated positively in the high-fat condition. CONCLUSIONS: The decrease in hypothalamic activity and the interaction with the insular cortex elicited by fat may contribute to an efficient energy homeostasis. Therefore, fat might be a modulator of homeostatic and gustatory brain regions and their interaction. This trial was registered at clinicaltrials.gov as NCT01516021.

Diet and risk of ischemic heart disease in India.

BACKGROUND: Ischemic heart disease (IHD) is a leading cause of death in India. Dietary changes could reduce risk, but few studies have addressed the association between diet and IHD risk in India. OBJECTIVE: The goal was to address the association between diet and IHD risk among Indians in New Delhi (northern India) and Bangalore (southern India). DESIGN: We collected data from 350 cases of acute myocardial infarction and 700 controls matched on the basis of age, sex, and hospital as part of a hospital-based case-control study in 8 hospitals. Long-term dietary intake was assessed by using food-frequency questionnaires developed for New Delhi and Bangalore. We used conditional logistic regression to control for the matching factors and other predictors of risk. RESULTS: We observed a significant and dose-dependent inverse association between vegetable intake and IHD risk. The inverse association was stronger for green leafy vegetables; in multivariate analysis, persons consuming a median of 3.5 servings/wk had a 67% lower relative risk (RR: 0.33; 95% CI: 0.17, 0.64; P for trend = 0.0001) than did those consuming 0.5 servings/wk. Controlling for other dietary covariates did not alter the association. Cereal intake was also associated with a lower risk. Use of mustard oil, which is rich in alpha-linolenic acid, was associated with a lower risk than was use of sunflower oil [for use in cooking: RR: 0.49 (95% CI: 0.24, 0.99); for use in frying, RR: 0.29 (95% CI: 0.13, 0.64)]. CONCLUSION: Diets rich in vegetables and use of mustard oil could contribute to the lower risk of IHD among Indians.

Impairment of endothelial function--a possible mechanism for atherosclerosis of a high-fat meal intake.

INTRODUCTION: Endothelial dysfunction is known to occur in patients with coronary artery disease. Flow-mediated dilation of the brachial artery using Doppler ultrasound is a non-invasive technique for the assessment of endothelial function. The objective of the study was to use the above method to evaluate the pathophysiology of high-fat (HF) intake on endothelial function in a local population. A popular local dish "nasi-lemak", a source of high saturated fat content from coconut milk, was chosen to represent a local high-fat meal (LHF). In addition, the effects of a Western high-fat (WHF) ("McDonald's") meal and a low-fat (LF) meal control on endothelial function were studied. MATERIALS AND METHODS: The study population consisted of 10 healthy male non-smoker (mean age 22 +/- 2 years) with normal body mass index, normal fasting sugar and lipid profiles. Nitric oxide dependent flow-mediated dilation and nitric oxide independent (GTN) dilation was assessed by Doppler flow in the brachial artery before and 4 hours after each meal on separate occasions by 2 experienced sonographers blinded to the type of meals. RESULTS: The baseline brachial artery size, baseline vessel flow and increase in flow after cuff deflation were similar for each of the six arterial studies. In response to reactive hyperaemia after cuff deflation, the endothelium-dependent dilation was significantly different between the meals. There was a marked decrease in endothelium-dependent dilation after the WHF meal compared to the LF meal (8.6 +/- 2.2% vs. -0.8 +/- 1.1%, P < 0.006). There was also a marked decrease in endothelium-dependent dilation after the LHF meal compared to the LF meal (7.7 +/- 2.1% vs. -0.8 +/- 1.1%, P < 0.001). When comparing between the two HF meals, the change in endothelium-dependent dilation was not significant (7.7 vs. 8.6%, P = 0.678). GTN-induced dilation was not significantly different before and after the LF, WHF or LHF (0.1 +/- 0.5% vs. 0.2 +/- 0.9% vs. 1.3 +/- 0.5%, P = 0.094). CONCLUSION: The results suggest that in a local population, impairment of endothelial function is a possible mechanism in the pathophysiology of atherosclerosis from HF intake, beyond just affecting lipid levels. This effect is observed after both a LHF and a WHF meal intake. This technique to study endothelial function may be a useful non-invasive screening tool in the study of other HF diet choices and provides further information for the education of the influence of dietary choices on atherosclerosis.

Higher bioaccessibility of iron and zinc from food grains in the presence of garlic and onion.

Bioavailability of micronutrients iron and zinc is particularly low from plant foods. Hence there is a need to evolve a food-based strategy to improve the same to combat widespread deficiencies of these minerals in a population dependent on plant foods. Dietary sulfur-containing amino acids have been reported to improve the mineral status of experimental animals. Our objective was to examine whether sulfur compound-rich Allium spices have a similar potential of beneficially modulating the mineral bioavailability. In this context, we examined the influence of exogenously added garlic and onion on the bioaccessibility of iron and zinc from food grains. Two representative cereals and pulses each were studied in both raw and cooked condition employing two levels of garlic (0.25 and 0.5 g/10 g of grain) and onion (1.5 and 3 g/10 g of grain). The enhancing effect of these two spices on iron bioaccessibility was generally evidenced in the case of both the cereals (9.4-65.9% increase) and pulses (9.9-73.3% increase) in both raw and cooked conditions. The two spices similarly enhanced the bioaccessibility of zinc from the food grains, the extent of increase in cereals ranging from 10.4% to 159.4% and in pulses from 9.8% to 49.8%. Thus, both garlic and onion were evidenced here to have a promoting influence on the bioaccessibility of iron and zinc from food grains. This novel information has the potential application in evolving a food-based strategy to improve the bioavailability of trace minerals and hence contributes to the human health benefit.

Food selection based on high total antioxidant capacity improves endothelial function in a low cardiovascular risk population.

BACKGROUND AND AIMS: Oxidative stress has been advocated as a major cause for cardiovascular disease (CVD), and low plasma antioxidant concentrations are associated with endothelial dysfunction, the first step towards atherosclerosis. However, although the antioxidant content in fruits and vegetables may explain at least in part their protective effect against CVD, supplementation with antioxidant vitamins fails to improve endothelial function and reduce CVD risk. The aim of this study was to investigate the impact of a diet rich in antioxidants on endothelial function measured by flow-mediated dilatation (FMD) in volunteers at low cardiovascular risk. METHODS AND RESULTS: In a crossover trial, 24 subjects (13 women, mean age 61 ± 3 years), received, in a randomised order, a 14-day high (HT) and a 14-day low (LT) antioxidant diets, with a 2-week wash-out (WO) in between. Both diets were comparable in daily portions of fruits and vegetables, and in alcohol, fibre and macronutrient intake, but differed in their total antioxidant capacity. Before and after each diet, anthropometrics, blood pressure, fasting plasma glucose, lipid profile, hepatic enzymes, circulating antioxidant concentrations, high sensitivity C-reactive protein (hs-CRP) and FMD were assessed. FMD increased significantly during the HT diet compared to the LT (p < 0.000). FMD values were 2.3% higher after HT compared with LT (p < 0.001) after adjustment for age, gender and diet order. α-tocopherol increased significantly (p < 0.05) and hs-CRP and of γ-glutamyltranspeptidase decreased significantly (p < 0.05 and p < 0.01, respectively) during the HT diet, compared with the LT diet. CONCLUSIONS: A short-term HT diet improves endothelial function in volunteers at low cardiovascular risk, which may further reduce their risk of CVD. Copyright © 2010 Elsevier B.V. All rights reserved.

The effect of a plant-based low-carbohydrate ("Eco-Atkins") diet on body weight and blood lipid concentrations in hyperlipidemic subjects.

BACKGROUND: Low-carbohydrate, high-animal protein diets, which are advocated for weight loss, may not promote the desired reduction in low-density lipoprotein cholesterol (LDL-C) concentration. The effect of exchanging the animal proteins and fats for those of vegetable origin has not been tested. Our objective was to determine the effect on weight loss and LDL-C concentration of a low-carbohydrate diet high in vegetable proteins from gluten, soy, nuts, fruits, vegetables, cereals, and vegetable oils compared with a high-carbohydrate diet based on low-fat dairy and whole grain products. METHODS: A total of 47 overweight hyperlipidemic men and women consumed either (1) a low-carbohydrate (26% of total calories), high-vegetable protein (31% from gluten, soy, nuts, fruit, vegetables, and cereals), and vegetable oil (43%) plant-based diet or (2) a high-carbohydrate lacto-ovo vegetarian diet (58% carbohydrate, 16% protein, and 25% fat) for 4 weeks each in a parallel study design. The study food was provided at 60% of calorie requirements. RESULTS: Of the 47 subjects, 44 (94%) (test, n = 22 [92%]; control, n = 22 [96%]) completed the study. Weight loss was similar for both diets (approximately 4.0 kg). However, reductions in LDL-C concentration and total cholesterol-HDL-C and apolipoprotein B-apolipoprotein AI ratios were greater for the low-carbohydrate compared with the high-carbohydrate diet (-8.1% [P = .002], -8.7% [P = .004], and -9.6% [P = .001], respectively). Reductions in systolic and diastolic blood pressure were also seen (-1.9% [P = .052] and -2.4% [P = .02], respectively). CONCLUSION: A low-carbohydrate plant-based diet has lipid-lowering advantages over a high-carbohydrate, low-fat weight-loss diet in improving heart disease risk factors not seen with conventional low-fat diets with animal products.

Bioavailability of curcumin: problems and promises.

Curcumin, a polyphenolic compound derived from dietary spice turmeric, possesses diverse pharmacologic effects including anti-inflammatory, antioxidant, antiproliferative and antiangiogenic activities. Phase I clinical trials have shown that curcumin is safe even at high doses (12 g/day) in humans but exhibit poor bioavailability. Major reasons contributing to the low plasma and tissue levels of curcumin appear to be due to poor absorption, rapid metabolism, and rapid systemic elimination. To improve the bioavailability of curcumin, numerous approaches have been undertaken. These approaches involve, first, the use of adjuvant like piperine that interferes with glucuronidation; second, the use of liposomal curcumin; third, curcumin nanoparticles; fourth, the use of curcumin phospholipid complex; and fifth, the use of structural analogues of curcumin (e.g., EF-24). The latter has been reported to have a rapid absorption with a peak plasma half-life. Despite the lower bioavailability, therapeutic efficacy of curcumin against various human diseases, including cancer, cardiovascular diseases, diabetes, arthritis, neurological diseases and Crohn's disease, has been documented. Enhanced bioavailability of curcumin in the near future is likely to bring this promising natural product to the forefront of therapeutic agents for treatment of human disease.

Steam cooking significantly improves in vitro bile acid binding of collard greens, kale, mustard greens, broccoli, green bell pepper, and cabbage.

Bile acid binding capacity has been related to the cholesterol-lowering potential of foods and food fractions. Lowered recirculation of bile acids results in utilization of cholesterol to synthesize bile acid and reduced fat absorption. Secondary bile acids have been associated with increased risk of cancer. Bile acid binding potential has been related to lowering the risk of heart disease and that of cancer. Previously, we have reported bile acid binding by several uncooked vegetables. However, most vegetables are consumed after cooking. How cooking would influence in vitro bile acid binding of various vegetables was investigated using a mixture of bile acids secreted in human bile under physiological conditions. Eight replicate incubations were conducted for each treatment simulating gastric and intestinal digestion, which included a substrate only, a bile acid mixture only, and 6 with substrate and bile acid mixture. Cholestyramine (a cholesterol-lowering, bile acid binding drug) was the positive control treatment and cellulose was the negative control. Relative to cholestyramine, in vitro bile acid binding on dry matter basis was for the collard greens, kale, and mustard greens, 13%; broccoli, 10%; Brussels sprouts and spinach, 8%; green bell pepper, 7%; and cabbage, 5%. These results point to the significantly different (P < or = .05) health-promoting potential of collard greens = kale = mustard greens > broccoli > Brussels sprouts = spinach = green bell pepper > cabbage as indicated by their bile acid binding on dry matter basis. Steam cooking significantly improved the in vitro bile acid binding of collard greens, kale, mustard greens, broccoli, green bell pepper, and cabbage compared with previously observed bile acid binding values for these vegetables raw (uncooked). Inclusion of steam-cooked collard greens, kale, mustard greens, broccoli, green bell pepper, and cabbage in our daily diet as health-promoting vegetables should be emphasized. These green/leafy vegetables, when consumed regularly after steam cooking, would lower the risk of cardiovascular disease and cancer, advance human nutrition research, and improve public health.

Effect of turmeric on urinary mutagens in smokers.

Curcumin, the active principle of turmeric, is known to act as an anti-oxidant, anti-mutagen and anti-carcinogen in experimental animals. In the present study, anti-mutagenic effects of turmeric were assessed in 16 chronic smokers. It was observed that turmeric, given in doses of 1.5 g/day for 30 days, significantly reduced the urinary excretion of mutagens in smokers. In contrast, in six non-smokers, who served as control, there was no change in the urinary excretion of mutagens after 30 days. Turmeric had no significant effect on serum aspartate aminotransferase and alanine aminotransferase, blood glucose, creatinine and lipid profile. These results indicate that dietary turmeric is an effective anti-mutagen and it may be useful in chemoprevention.

Postprandial anti-inflammatory and antioxidant effects of extra virgin olive oil.

High postprandial serum lipid concentrations are associated with increased oxidative stress which, in turn, increases the risk of atherosclerosis. Epidemiological studies correlate lower incidence of cardiovascular disease with adherence to the Mediterranean diet. The aim of this study was to evaluate changes in inflammatory (TXB(2) and LTB(4)) and oxidative stress markers (urinary hydrogen peroxide levels and serum antioxidant capacity), in addition to classic lipid parameters, after a fat-rich meal administered to 12 normolipemic, healthy subjects. Following a Latin square design, subjects were divided into three groups, each one receiving a different kind of oil (extra virgin olive oil; EVOO, olive oil; OO or corn oil; CO, together with 150g of potatoes), with 2-week washout periods between treatments. Blood samples were drawn at baseline and after 1, 2, and 6h after the meal. A significant decrease in inflammatory markers, namely TXB(2) and LTB(4), after 2 and 6h after EVOO (but not OO or CO) consumption and a concomitant increase of serum antioxidant capacity were recorded. These data reinforce the notion that the Mediterranean diet reduces the incidence of coronary heart disease partially due to the protective role of its phenolic components, including those of extra virgin olive oil.

Zinc and multi-mineral supplementation should mitigate the pathogenic impact of cadmium exposure.

High-level cadmium (Cd) exposure has long been known to induce nephropathy, severe osteoporosis, and fractures in humans. More recent epidemiology, however, reveals that, in populations not known to have important industrial exposure to this heavy metal, high-normal blood or urine Cd levels correlate with increased risk for vascular disorders, cancers, diabetes, and total mortality, as well as osteoporosis and nephropathy. Since these disorders appear unlikely to expedite Cd absorption, and since Cd has promoted these pathologies in rodent studies, it seems reasonable to conclude that Cd is an important mediating risk factor for these disorders in humans. Avoiding tobacco smoke or frequent ingestion of shellfish or organ meats can lessen humans exposure to Cd, but the chief dietary sources of Cd are plant-derived foods - green leafy vegetables, whole grains, tubers, and root vegetables - typically recommended for their health-supportive properties; indeed, among non-smokers, vegans tend to have the highest Cd body burden. Fortunately, iron sufficiency and ample dietary intakes of calcium, magnesium, and zinc can impede absorption of dietary Cd, both by down-regulating intestinal expression of mineral transporters, and by directly competing with Cd for access to these transporters. Correction of iron deficiency appears to be of particular importance for controlling Cd absorption. Moreover, zinc supplementation can counteract the toxicity of Cd already in the body via induction of metallothionein, which binds Cd avidly via its sulfhydryl groups; so long as it remains sequestered in this form, Cd is innocuous. Zinc supplementation may in any case be recommendable, as optimal zinc status exerts protective anti-inflammatory, antioxidant, and immunosupportive effects. Inasmuch as the toxicity of Cd appears to be mediated in large part by oxidative stress, ingestion of spirulina, lipoic acid, melatonin, and N-acetylcysteine may also have potential for mitigating the risk associated with Cd exposure, as suggested by rodent studies. Hence, although Cd may prove to be a major risk factor for morbidity and mortality in humans, practical strategies for limiting its absorption and pathogenic impact are at hand. Copyright © 2012 Elsevier Ltd. All rights reserved.

Curcumin and obesity.

Turmeric has been long recognized for its anti-inflammatory and health-promoting properties. Curcumin is one of the principal anti-inflammatory and healthful components of turmeric comprising 2-8% of most turmeric preparations. Experimental evidence supports the activity of curcumin in promoting weight loss and reducing the incidence of obesity-related diseases. With the discovery that obesity is characterized by chronic low-grade metabolic inflammation, phytochemicals like curcumin which have anti-inflammatory activity are being intensely investigated. Recent scientific research reveals that curcumin directly interacts with white adipose tissue to suppress chronic inflammation. In adipose tissue, curcumin inhibits macrophage infiltration and nuclear factor κB (NF-κB) activation induced by inflammatory agents. Curcumin reduces the expression of the potent proinflammatory adipokines tumor necrosis factor-α (TNFα), monocyte chemoattractant protein-1 (MCP-1), and plasminogen activator inhibitor type-1 (PAI-1), and it induces the expression of adiponectin, the principal anti-inflammatory agent secreted by adipocytes. Curcumin also has effects to inhibit adipocyte differentiation and to promote antioxidant activities. Through these diverse mechanisms curcumin reduces obesity and curtails the adverse health effects of obesity. Copyright © 2013 International Union of Biochemistry and Molecular Biology, Inc.

Strawberry modulates LDL oxidation and postprandial lipemia in response to high-fat meal in overweight hyperlipidemic men and women.

BACKGROUND: Elevated levels of lipids, such as total cholesterol (TC), low-density lipoprotein cholesterol (LDL), and triglycerides (TG), are widely recognized as risk factors for cardiovascular disease (CVD). Oxidized LDL (OxLDL) is an emerging risk factor considered relevant in oxidative stress and endothelial dysfunction, which is implicated in the progression of CVD. Consumption of a diet rich in polyphenols may be cardioprotective through its impact on oxidative stress and protecting LDL from oxidation. OBJECTIVES: This study was designed to test the ability of strawberry phenolic compounds to mitigate the postprandial effects of a high-fat meal on OxLDL as well as investigate the effects of phenolic compounds on lipid metabolism. METHODS: Twenty-four hyperlipidemic men and women (14 women, 10 men; mean age 50.9 +/- SD 15 years) were recruited to participate in this randomized, single-blind, placebo-controlled, 12-wk crossover trial. After a 10-day run-in period, subjects consumed either an active strawberry beverage (Str; containing 10 g freeze-dried fruit) or a placebo (Pbo) beverage matched in energy and macronutrient composition for 6 weeks. Twice before randomization and once at the 6-week crossover point, subjects received either Str or Pbo with a high-fat challenge meal (HFM). TC, LDL, high-density lipoprotein cholesterol, TG, and OxLDL were measured at defined intervals for 6 h before and after HFM challenge. Fasting concentrations of blood variables at 0, 6, and 12 weeks were compared to assess chronic intake of Str or Pbo. RESULTS: After the HFM during the run-in period, TG and OxLDL were lower after Str than Pbo (p = 0.005, p = 0.01, and p = 0.0008, respectively). HFM responses after 6 weeks of Str versus Pbo resulted in decreased lipid levels and a sex by treatment interaction for OxLDL (p = < 0.0001, and p = 0.0002). CONCLUSION: The present results support a role for strawberry in mitigating fed-state oxidative stressors that may contribute to atherogenesis.

Antioxidants prevent health-promoting effects of physical exercise in humans

Exercise promotes longevity and ameliorates type 2 diabetes mellitus and insulin resistance. However, exercise also increases mitochondrial formation of presumably harmful reactive oxygen species (ROS). Antioxidants are widely used as supplements but whether they affect the health-promoting effects of exercise is unknown. We evaluated the effects of a combination of vitamin C (1000 mg/day) and vitamin E (400 IU/day) on insulin sensitivity as measured by glucose infusion rates (GIR) during a hyperinsulinemic, euglycemic clamp in previously untrained (n = 19) and pretrained (n = 20) healthy young men. Before and after a 4 week intervention of physical exercise, GIR was determined, and muscle biopsies for gene expression analyses as well as plasma samples were obtained to compare changes over baseline and potential influences of vitamins on exercise effects. Exercise increased parameters of insulin sensitivity (GIR and plasma adiponectin) only in the absence of antioxidants in both previously untrained (P < 0.001) and pretrained (P < 0.001) individuals. This was paralleled by increased expression of ROS-sensitive transcriptional regulators of insulin sensitivity and ROS defense capacity, peroxisome-proliferator-activated receptor gamma (PPARγ), and PPARγ coactivators PGC1α and PGC1β only in the absence of antioxidants (P < 0.001 for all). Molecular mediators of endogenous ROS defense (superoxide dismutases 1 and 2; glutathione peroxidase) were also induced by exercise, and this effect too was blocked by antioxidant supplementation. Consistent with the concept of mitohormesis, exercise-induced oxidative stress ameliorates insulin resistance and causes an adaptive response promoting endogenous antioxidant defense capacity. Supplementation with antioxidants may preclude these health-promoting effects of exercise in humans.

The protective effect of the flavonoids on food-mutagen-induced DNA damage in peripheral blood lymphocytes from colon cancer patients.

The food mutagens IQ (2-amino-3-methylimidazo[4,5-f]quinoline) and PhIP (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine) are heterocyclic amines (HCA), generated when heating proteinaceous food. This study investigates the protective potential of the flavonoids quercetin (Q) and rutin (R) against oxidative stress induced in vitro by IQ and PhIP in lymphocytes from healthy individuals and untreated, newly diagnosed colon cancer patients using the Comet assay. In the presence of up to 500μM Q and R, the DNA damage resulting from a high dose of PhIP (75μM) or IQ (150μM) was significantly reduced (P<0.001) to levels comparable to six times lower IQ or 7.5 times lower PhIP doses. Lymphocytes from colon cancer patients had greater baseline DNA damage than those from healthy individuals (P<0.01) and this higher level of damage was also observed throughout in vitro treatment. Except for the >50years of age group and male gender, confounding factors such as smoking, drinking and/or dietary habits were not found to be significant. In conclusion, flavonoids reduced oxidative stress caused by food mutagens in vitro in lymphocytes of healthy individuals and colon cancer patients. Thus, dietary supplementation with flavonoid-rich vegetables and fruits may prove very effective in protecting against oxidative stress. Copyright © 2011 Elsevier Ltd. All rights reserved.

Postprandial plasma lipid hydroperoxides: a possible link between diet and atherosclerosis.

There is increasing evidence implicating a dietary source of plasma lipid peroxides that become elevated in the postprandial state. This phenomenon may be a contributing factor to the correlation found between postprandial hyperlipidemia and increased risk of cardiovascular disease. Using a newly developed method for measuring lipid hydroperoxides directly in plasma, a pilot study was performed which revealed that lipid hydroperoxides are indeed elevated following a fatty meal. Lipid hydroperoxides increased within 2-4 h after the meal and returned to basal levels, corresponding to the usual postprandial hyperlipidemia. A marked suppression of postprandial hydroperoxides was found when a meal was consumed with wine, suggesting that these hydroperoxides can be formed and then absorbed during the digestive process.

Consumption of Brussels sprouts protects peripheral human lymphocytes against 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and oxidative ...

To find out if the cancer protective effects of Brussels sprouts seen in epidemiological studies are due to protection against DNA-damage, an intervention trial was conducted in which the impact of vegetable consumption on DNA-stability was monitored in lymphocytes with the comet assay. After consumption of the sprouts (300 g/p/d, n = 8), a reduction of DNA-migration (97%) induced by the heterocyclic aromatic amine 2-amino-1-methyl-6-phenyl-imidazo-[4,5-b]pyridine (PhIP) was observed whereas no effect was seen with 3-amino-1-methyl-5H-pyrido[4,3-b]-indole (Trp-P-2). This effect protection may be due to inhibition of sulfotransferase 1A1, which plays a key role in the activation of PhIP. In addition, a decrease of the endogenous formation of oxidized bases was observed and DNA-damage caused by hydrogen peroxide was significantly (39%) lower after the intervention. These effects could not be explained by induction of antioxidant enzymes glutathione peroxidase and superoxide dismutase, but in vitro experiments indicate that sprouts contain compounds, which act as direct scavengers of reactive oxygen species. Serum vitamin C levels were increased by 37% after sprout consumption but no correlations were seen between prevention of DNA-damage and individual alterations of the vitamin levels. Our study shows for the first time that sprout consumption leads to inhibition of sulfotransferases in humans and to protection against PhIP and oxidative DNA-damage.

Health benefits of nut consumption with special reference to body weight control.

Nuts are an integral part of the Mediterranean food patterns, and their incorporation into the regular diets of human beings is believed to provide many health benefits. The recent recognition of nuts as "heart-healthy" foods by the U.S. Food and Drug Administration has given a major boost to the positive image of nuts. Nut consumption has been associated with several health benefits, such as antioxidant, hypocholesterolemic, cardioprotective, anticancer, anti-inflammatory, and antidiabetic benefits, among other functional properties. However, although nuts possess these many health benefits, their consumption has been hampered by a lack of adequate information regarding those benefits. In addition, because nuts are energy-dense foods with high-fat content, there is a misconception among consumers that increased consumption may lead to unwanted gain in body weight with the risk of developing overweight/obesity. Nonetheless, available epidemiologic studies and short-term controlled feeding trials have supported the theory that the inclusion of nuts in the typical diet does not induce weight gain, despite an expected increase in total caloric intake. To address the misperception about nuts and body weight gain, the present review focuses mainly on the relation between nut consumption and body weight gain, in the context of the many health benefits of nuts. Copyright © 2012 Elsevier Inc. All rights reserved.

Antioxidant capacity and other bioactivities of the freeze-dried Amazonian palm berry, Euterpe oleraceae mart. (acai).

The fruit of Euterpe oleraceae, commonly known as acai, has been demonstrated to exhibit significantly high antioxidant capacity in vitro, especially for superoxide and peroxyl scavenging, and, therefore, may have possible health benefits. In this study, the antioxidant capacities of freeze-dried acai fruit pulp/skin powder (OptiAcai) were evaluated by different assays with various free radical sources. It was found to have exceptional activity against superoxide in the superoxide scavenging (SOD) assay, the highest of any food reported to date against the peroxyl radical as measured by the oxygen radical absorbance capacity assay with fluorescein as the fluorescent probe (ORACFL), and mild activity against both the peroxynitrite and hydroxyl radical by the peroxynitrite averting capacity (NORAC) and hydroxyl radical averting capacity (HORAC) assays, respectively. The SOD of acai was 1614 units/g, an extremely high scavenging capacity for O2*-, by far the highest of any fruit or vegetable tested to date. Total phenolics were also tested as comparison. In the total antioxidant (TAO) assay, antioxidants in acai were differentiated into "slow-acting" and "fast-acting" components. An assay measuring inhibition of reactive oxygen species (ROS) formation in freshly purified human neutrophils showed that antioxidants in acai are able to enter human cells in a fully functional form and to perform an oxygen quenching function at very low doses. Furthermore, other bioactivities related to anti-inflammation and immune functions were also investigated. Acai was found to be a potential cyclooxygenase (COX)-1 and COX-2 inhibitor. It also showed a weak effect on lipopolysaccharide (LPS)-induced nitric oxide but no effect on either lymphocyte proliferation and phagocytic capacity.

High Fat Intake Leads to Acute Postprandial Exposure to Circulating Endotoxin in Type 2 Diabetic Subjects

OBJECTIVE To evaluate the changes in circulating endotoxin after a high–saturated fat meal to determine whether these effects depend on metabolic disease state. RESEARCH DESIGN AND METHODS Subjects (n = 54) were given a high-fat meal (75 g fat, 5 g carbohydrate, 6 g protein) after an overnight fast (nonobese control [NOC]: age 39.9 ± 11.8 years [mean ± SD], BMI 24.9 ± 3.2 kg/m2, n = 9; obese: age 43.8 ± 9.5 years, BMI 33.3 ± 2.5 kg/m2, n = 15; impaired glucose tolerance [IGT]: age 41.7 ± 11.3 years, BMI 32.0 ± 4.5 kg/m2, n = 12; type 2 diabetic: age 45.4 ± 10.1 years, BMI 30.3 ± 4.5 kg/m2, n = 18). Blood was collected before (0 h) and after the meal (1–4 h) for analysis. RESULTS Baseline endotoxin was significantly higher in the type 2 diabetic and IGT subjects than in NOC subjects, with baseline circulating endotoxin levels 60.6% higher in type 2 diabetic subjects than in NOC subjects (P < 0.05). Ingestion of a high-fat meal led to a significant rise in endotoxin levels in type 2 diabetic, IGT, and obese subjects over the 4-h time period (P < 0.05). These findings also showed that, at 4 h after a meal, type 2 diabetic subjects had higher circulating endotoxin levels (125.4%↑) than NOC subjects (P < 0.05). CONCLUSIONS These studies have highlighted that exposure to a high-fat meal elevates circulating endotoxin irrespective of metabolic state, as early as 1 h after a meal. However, this increase is substantial in IGT and type 2 diabetic subjects, suggesting that metabolic endotoxinemia is exacerbated after high fat intake. In conclusion, our data suggest that, in a compromised metabolic state such as type 2 diabetes, a continual snacking routine will cumulatively promote their condition more rapidly than in other individuals because of the greater exposure to endotoxin.

Curry consumption and cognitive function in the elderly.

Curcumin, from the curry spice turmeric, has been shown to possess potent antioxidant and antiinflammatory properties and to reduce beta-amyloid and plaque burden in experimental studies, but epidemiologic evidence is lacking. The authors investigated the association between usual curry consumption level and cognitive function in elderly Asians. In a population-based cohort (n = 1,010) of nondemented elderly Asian subjects aged 60-93 years in 2003, the authors compared Mini-Mental State Examination (MMSE) scores for three categories of regular curry consumption, taking into account known sociodemographic, health, and behavioral correlates of MMSE performance. Those who consumed curry "occasionally" and "often or very often" had significantly better MMSE scores than did subjects who "never or rarely" consumed curry. The authors reported tentative evidence of better cognitive performance from curry consumption in nondemented elderly Asians, which should be confirmed in future studies.

Paleolithic nutrition: twenty-five years later.

A quarter century has passed since the first publication of the evolutionary discordance hypothesis, according to which departures from the nutrition and activity patterns of our hunter-gatherer ancestors have contributed greatly and in specifically definable ways to the endemic chronic diseases of modern civilization. Refinements of the model have changed it in some respects, but anthropological evidence continues to indicate that ancestral human diets prevalent during our evolution were characterized by much lower levels of refined carbohydrates and sodium, much higher levels of fiber and protein, and comparable levels of fat (primarily unsaturated fat) and cholesterol. Physical activity levels were also much higher than current levels, resulting in higher energy throughput. We said at the outset that such evidence could only suggest testable hypotheses and that recommendations must ultimately rest on more conventional epidemiological, clinical, and laboratory studies. Such studies have multiplied and have supported many aspects of our model, to the extent that in some respects, official recommendations today have targets closer to those prevalent among hunter-gatherers than did comparable recommendations 25 years ago. Furthermore, doubts have been raised about the necessity for very low levels of protein, fat, and cholesterol intake common in official recommendations. Most impressively, randomized controlled trials have begun to confirm the value of hunter-gatherer diets in some high-risk groups, even as compared with routinely recommended diets. Much more research needs to be done, but the past quarter century has proven the interest and heuristic value, if not yet the ultimate validity, of the model.

Effects of Diets High in Walnuts and Flax Oil on Hemodynamic Responses to Stress and Vascular Endothelial Function

Background Polyunsaturated fatty acids (PUFA) have beneficial effects on cardiovascular risk, although the mechanisms are incompletely understood. In a previous article, we showed significant reductions in low-density lipoprotein cholesterol and several markers of inflammation with increasing intake of alpha-linolenic acid (ALA) from walnuts and flax. Objective To examine effects of ALA on cardiovascular responses to acute stress, flow-mediated dilation (FMD) of the brachial artery, and blood concentrations of endothelin-1 and arginine-vasopressin (AVP). Design Using a randomized, crossover study design, cardiovascular responses to acute stress were assessed in 20 hypercholesterolemic subjects, a subset of whom also underwent FMD testing (n = 12). Participants were fed an average American diet (AAD) and 2 experimental diets that varied in the amount of ALA and linoleic acid (LA) that they contained. The AAD provided 8.7% energy from PUFA (7.7% LA, 0.8% ALA). On the LA diet, saturated fat was reduced, and PUFA from walnuts and walnut oil provided 16.4% of energy (12.6% LA, 3.6% ALA). On the ALA diet, walnuts, walnut oil, and flax oil provided 17% energy from PUFA (10.5% LA, 6.5% ALA). Results The ALA and LA diets significantly reduced diastolic blood pressure (−2 to −3 mm Hg) and total peripheral resistance (−4%), and this effect was evident at rest and during stress (main effect of diet, p < 0.02). FMD increased (+34%) on the diet containing additional ALA. AVP also increased by 20%, and endothelin-1 was unchanged. Conclusions These results suggest novel mechanisms for the cardioprotective effects of walnuts and flax, and further work is needed to identify the bioactives responsible for these effects.

Antioxidants as antidepressants: fact or fiction?

Depression is a medical condition with a complex biological pattern of aetiology, involving genetic and epigenetic factors, along with different environmental stressors. Recent evidence suggests that oxidative stress processes might play a relevant role in the pathogenic mechanism(s) underlying many major psychiatric disorders, including depression. Reactive oxygen and nitrogen species have been shown to modulate levels and activity of noradrenaline (norepinephrine), serotonin, dopamine and glutamate, the principal neurotransmitters involved in the neurobiology of depression. Major depression has been associated with lowered concentrations of several endogenous antioxidant compounds, such as vitamin E, zinc and coenzyme Q10, or enzymes, such as glutathione peroxidase, and with an impairment of the total antioxidant status. These observations introduce new potential targets for the development of therapeutic interventions based on antioxidant compounds. The present review focuses on the possible role of oxidative stress processes in the pathogenesis of depression. The therapeutic potential of antioxidant compounds as a co-adjuvant treatment to conventional antidepressants is discussed. For instance, N-acetyl-cysteine has been shown to have a significant benefit on depressive symptoms in a randomized placebo-controlled trial. Additionally, curcumin, the yellow pigment of curry, has been shown to strongly interfere with neuronal redox homeostasis in the CNS and to possess antidepressant activity in various animal models of depression, also thanks to its ability to inhibit monoamine oxidases. There is an urgent need to develop better tolerated and more effective treatments for depressive disorders and several antioxidant treatments appear promising and deserve further study.

Butyrate and other short-chain fatty acids as modulators of immunity: what relevance for health?

PURPOSE OF REVIEW: High-fiber diets have been shown to reduce plasma concentrations of inflammation markers. Increased production of fermentation-derived short-chain fatty acids (SCFAs) is one of the factors that could exert these positive effects. This review examines the effects of SCFAs on immune cells and discusses the relevance of their effects on systemic inflammation, as frequently seen in obesity. RECENT FINDINGS: SCFAs have been shown to reduce chemotaxis and cell adhesion; this effect is dependent on type and concentration of SCFA. In spite of conflicting results, especially butyrate seems to have an anti-inflammatory effect, mediated by signaling pathways like nuclear factor-κB and inhibition of histone deacetylase. The discrepancies in the results could be explained by differences in cell types used and their proliferative and differentiation status. SUMMARY: SCFAs show anti-inflammatory effects and seem to have the potency to prevent infiltration of immune cells from the bloodstream in, for example, the adipose tissue. In addition, their ability to inhibit the proliferation and activation of T cells and to prevent adhesion of antigen-presenting cells could be important as it recently has been shown that obesity-associated inflammation might be antigen-dependent. More studies with concentrations in micromolar range are needed to approach more physiological concentrations.

Antioxidant-induced changes of the AP-1 transcription complex are paralleled by a selective suppression of human papillomavirus transcription.

Considering the involvement of a redox-regulatory pathway in the expression of human papillomaviruses (HPVs), HPV type 16 (HPV-16)-immortalized human keratinocytes were treated with the antioxidant pyrrolidine-dithiocarbamate (PDTC). PDTC induces elevated binding of the transcription factor AP-1 to its cognate recognition site within the viral regulatory region. Despite of increased AP-1 binding, normally indispensable for efficient HPV-16 transcription, viral gene expression was selectively suppressed at the level of initiation of transcription. Electrophoretic mobility supershift assays showed that the composition of the AP-1 complex, predominantly consisting of Jun homodimers in untreated cells, was altered. Irrespective of enhanced c-fos expression, c-jun was phosphorylated and became primarily heterodimerized with fra-1, which was also induced after PDTC incubation. Additionally, there was also an increased complex formation between c-jun and junB. Because both fra-1 and junB overexpression negatively interferes with c-jun/c-fos trans-activation of AP-1-responsive genes, our results suggest that the observed block in viral transcription is mainly the consequence of an antioxidant-induced reconstitution of the AP-1 transcription complex. Since expression of the c-jun/c-fos gene family is tightly regulated during cellular differentiation, defined reorganization of a central viral transcription factor may represent a novel mechanism controlling the transcription of pathogenic HPVs during keratinocyte differentiation and in the progression to cervical cancer.

Curcumin as "Curecumin": from kitchen to clinic.

Although turmeric (Curcuma longa; an Indian spice) has been described in Ayurveda, as a treatment for inflammatory diseases and is referred by different names in different cultures, the active principle called curcumin or diferuloylmethane, a yellow pigment present in turmeric (curry powder) has been shown to exhibit numerous activities. Extensive research over the last half century has revealed several important functions of curcumin. It binds to a variety of proteins and inhibits the activity of various kinases. By modulating the activation of various transcription factors, curcumin regulates the expression of inflammatory enzymes, cytokines, adhesion molecules, and cell survival proteins. Curcumin also downregulates cyclin D1, cyclin E and MDM2; and upregulates p21, p27, and p53. Various preclinical cell culture and animal studies suggest that curcumin has potential as an antiproliferative, anti-invasive, and antiangiogenic agent; as a mediator of chemoresistance and radioresistance; as a chemopreventive agent; and as a therapeutic agent in wound healing, diabetes, Alzheimer disease, Parkinson disease, cardiovascular disease, pulmonary disease, and arthritis. Pilot phase I clinical trials have shown curcumin to be safe even when consumed at a daily dose of 12g for 3 months. Other clinical trials suggest a potential therapeutic role for curcumin in diseases such as familial adenomatous polyposis, inflammatory bowel disease, ulcerative colitis, colon cancer, pancreatic cancer, hypercholesteremia, atherosclerosis, pancreatitis, psoriasis, chronic anterior uveitis and arthritis. Thus, curcumin, a spice once relegated to the kitchen shelf, has moved into the clinic and may prove to be "Curecumin".

A systematic screening of total antioxidants in dietary plants.

A predominantly plant-based diet reduces the risk for development of several chronic diseases. It is often assumed that antioxidants contribute to this protection, but results from intervention trials with single antioxidants administered as supplements quite consistently do not support any benefit. Because dietary plants contain several hundred different antioxidants, it would be useful to know the total concentration of electron-donating antioxidants (i.e., reductants) in individual items. Such data might be useful in the identification of the most beneficial dietary plants. We have assessed systematically total antioxidants in a variety of dietary plants used worldwide, including various fruits, berries, vegetables, cereals, nuts and pulses. When possible, we analyzed three or more samples of dietary plants from three different geographic regions in the world. Total antioxidants was assessed by the reduction of Fe(3+) to Fe(2+) (i.e., the FRAP assay), which occurred rapidly with all reductants with half-reaction reduction potentials above that of Fe(3+)/Fe(2+). The values, therefore, expressed the corresponding concentration of electron-donating antioxidants. Our results demonstrated that there is more than a 1000-fold difference among total antioxidants in various dietary plants. Plants that contain most antioxidants included members of several families, such as Rosaceae (dog rose, sour cherry, blackberry, strawberry, raspberry), Empetraceae (crowberry), Ericaceae (blueberry), Grossulariaceae (black currant), Juglandaceae (walnut), Asteraceae (sunflower seed), Punicaceae (pomegranate) and Zingiberaceae (ginger). In a Norwegian diet, fruits, berries and cereals contributed 43.6%, 27.1% and 11.7%, respectively, of the total intake of plant antioxidants. Vegetables contributed only 8.9%. The systematic analysis presented here will facilitate research into the nutritional role of the combined effect of antioxidants in dietary plants.

Diverse effects of a low dose supplement of lipidated curcumin in healthy middle aged people

Background Curcumin extracts of turmeric are proposed to produce health benefits. To date, human intervention studies have focused mainly on people with existing health problems given high doses of poorly absorbed curcumin. The purpose of the current study was to check whether in healthy people, a low dose of a lipidated curcumin extract could alter wellness-related measures. Methods The present study was conducted in healthy middle aged people (40–60 years old) with a low dose of curcumin (80 mg/day) in a lipidated form expected to have good absorption. Subjects were given either curcumin (N = 19) or placebo (N = 19) for 4 wk. Blood and saliva samples were taken before and after the 4 weeks and analyzed for a variety of blood and saliva measures relevant to health promotion. Results Curcumin, but not placebo, produced the following statistically significant changes: lowering of plasma triglyceride values, lowering of salivary amylase levels, raising of salivary radical scavenging capacities, raising of plasma catalase activities, lowering of plasma beta amyloid protein concentrations, lowering of plasma sICAM readings, increased plasma myeloperoxidase without increased c-reactive protein levels, increased plasma nitric oxide, and decreased plasma alanine amino transferase activities. Conclusion Collectively, these results demonstrate that a low dose of a curcumin-lipid preparation can produce a variety of potentially health promoting effects in healthy middle aged people.

Processed meat and colorectal cancer: a review of epidemiologic and experimental evidence

Processed meat intake may be involved in the etiology of colorectal cancer, a major cause of death in affluent countries. The epidemiologic studies published to date conclude that the excess risk in the highest category of processed meat-eaters is comprised between 20 and 50% compared with non-eaters. In addition, the excess risk per gram of intake is clearly higher than that of fresh red meat. Several hypotheses, which are mainly based on studies carried out on red meat, may explain why processed meat intake is linked to cancer risk. Those that have been tested experimentally are (i) that high-fat diets could promote carcinogenesis via insulin resistance or fecal bile acids; (ii) that cooking meat at a high temperature forms carcinogenic heterocyclic amines and polycyclic aromatic hydrocarbons; (iii) that carcinogenic N-nitroso compounds are formed in meat and endogenously; (iv) that heme iron in red meat can promote carcinogenesis because it increases cell proliferation in the mucosa, through lipoperoxidation and/or cytotoxicity of fecal water. Nitrosation might increase the toxicity of heme in cured products. Solving this puzzle is a challenge that would permit to reduce cancer load by changing the processes rather than by banning processed meat.

Diets high in palmitic acid (16:0), lauric and myristic acids (12:0 + 14:0), or oleic acid (18:1) do not alter postprandial or fasting plasma homoc...

BACKGROUND: Dietary fat type is known to modulate the plasma lipid profile, but its effects on plasma homocysteine and inflammatory markers are unclear. OBJECTIVE: We investigated the effects of high-protein Malaysian diets prepared with palm olein, coconut oil (CO), or virgin olive oil on plasma homocysteine and selected markers of inflammation and cardiovascular disease (CVD) in healthy adults. DESIGN: A randomized-crossover intervention with 3 dietary sequences of 5 wk each was conducted in 45 healthy subjects. The 3 test fats, namely palmitic acid (16:0)-rich palm olein (PO), lauric and myristic acid (12:0 + 14:0)-rich CO, and oleic acid (18:1)-rich virgin olive oil (OO), were incorporated at two-thirds of 30% fat calories into high-protein Malaysian diets. RESULTS: No significant differences were observed in the effects of the 3 diets on plasma total homocysteine (tHcy) and the inflammatory markers TNF-α, IL-1β, IL-6, and IL-8, high-sensitivity C-reactive protein, and interferon-γ. Diets prepared with PO and OO had comparable nonhypercholesterolemic effects; the postprandial total cholesterol for both diets and all fasting lipid indexes for the OO diet were significantly lower (P < 0.05) than for the CO diet. Unlike the PO and OO diets, the CO diet was shown to decrease postprandial lipoprotein(a). CONCLUSION: Diets that were rich in saturated fatty acids prepared with either PO or CO, and an OO diet that was high in oleic acid, did not alter postprandial or fasting plasma concentrations of tHcy and selected inflammatory markers. This trial was registered at clinicaltrials.gov as NCT00941837.

Heterocyclic amines: Mutagens/carcinogens produced during cooking of meat and fish.

Research leading to the discovery of a series of mutagenic and carcinogenic heterocyclic amines (HCAs) was inspired by the idea that smoke produced during cooking of food, especially meat or fish, might be carcinogenic. More than ten kinds of HCAs, actually produced by cooking or heating of meat or fish, have now been isolated and their structures determined, most being previously unregistered compounds. They are highly mutagenic towards Salmonella typhimurium in the presence of S9 mix and are also mutagenic in vitro and in vivo toward mammalian cells. HCAs have now been chemically synthesized in quantity and subjected to long-term animal testing. When HCAs were fed in the diet, rodents developed cancers in many organs, including the colon, breast and prostate, and one HCA produced hepatomas in monkeys. The lesions exhibited alteration in genes including Apc, beta-catenin and Ha-ras, and these changes provide clues to the induction mechanisms. The HCAs are oxidized to hydroxyamino derivatives by cytochrome P450s, and further converted to ester forms by acetyltransferase and sulfotransferase. Eventually, they produce DNA adducts through the formation of N-C bonds at guanine bases. There are HCA-sensitive and resistant strains of rodents and a search for the responsible genes is now under way. While the content of HCAs in dishes consumed in ordinary life is low and not sufficient in itself to explain human cancer, the coexistence of many other mutagens/carcinogens of either autobiotic or xenobiotic type and the possibility that HCAs induce genomic instability and heightened sensitivity to tumor promoters suggest that avoidance of exposure to HCAs or reduction of HCAs' biological effects as far as possible are to be highly recommended. Usage of microwave ovens for cooking and supplementation of the diet, for example with soy-isoflavones, which have been found to suppress the occurrence of HCA-induced breast cancers, should be encouraged. Advice to the general public about how to reduce the carcinogenic load imposed by HCAs would be an important contribution to cancer prevention.

Olive, soybean and palm oils intake have a similar acute detrimental effect over the endothelial function in healthy young subjects.

BACKGROUND AND AIM: Currently, more than 30% of the caloric intake in the Colombian population comes from vegetable oil consumption mainly by the ingestion of deep-fried foods. Recently, it has been reported that unsaturated fatty acid rich oils have a beneficial effect on the endothelial function. Nevertheless, it is well know that the deep-frying process alters the chemical composition of vegetable oils and can produce adverse effects in the endothelial function. OBJECTIVE: To evaluate the acute effect of the ingestion of large amounts of olive, soybean and palm oils, fresh and at two different deep-fry levels, on the glucose and lipid profiles and the endothelial function. METHODS AND RESULTS: Ten healthy young volunteers were included in the study. After performing a baseline evaluation of cardiovascular risk factors and drawing a fasting blood sample, subjects were exposed to a randomly assigned potato soup meal containing 60 mL of one of three different vegetable oils (olive, soybean and palm), either fresh or at one of two different deep-fry levels (10 and 20 fries, respectively). Flow-mediated vasodilation (FMD) was performed in fasting conditions and 3h after the intake of the oil rich meal. Furthermore, blood samples were taken at these stages for the lipid profiles and plasma glucose determinations. All the meals resulted in a similar acute endothelial impairment (FMD decrease of 32.1%, confidence interval [CI] 95%, 28.0-36.2) and postprandial increase in triglycerides (27.03%, CI 95%, 20.5-33.3), independently of the type of oil ingested (p=0.44) and regardless of its deep-fry level (p=0.62). No correlation was found between endothelial impairment and postprandial triglyceride increment (r=-0.22, p=0.09). CONCLUSIONS: No difference was found in the acute adverse effect of the ingestion of different vegetable oils on the endothelial function. All the vegetable oils, fresh and deep-fried, produced an increase in the triglyceride plasma levels in healthy subjects.

Cancer inhibition by inositol hexaphosphate (IP6) and inositol: from laboratory to clinic.

Inositol hexaphosphate (IP6) is a naturally occurring polyphosphorylated carbohydrate that is present in substantial amounts in almost all plant and mammalian cells. It was recently recognized to possess multiple biological functions. A striking anticancer effect of IP6 was demonstrated in different experimental models. Inositol is also a natural constituent possessing moderate anticancer activity. The most consistent and best anticancer results were obtained from the combination of IP6 plus inositol. In addition to reducing cell proliferation, IP6 increases differentiation of malignant cells, often resulting in a reversion to normal phenotype. Exogenously administered IP6 is rapidly taken into the cells and dephosphorylated to lower-phosphate inositol phosphates, which further interfere with signal transduction pathways and cell cycle arrest. Enhanced immunity and antioxidant properties can also contribute to tumor cell destruction. However, the molecular mechanisms underlying this anticancer action are not fully understood. Because it is abundantly present in regular diet, efficiently absorbed from the gastrointestinal tract, and safe, IP6 holds great promise in our strategies for the prevention and treatment of cancer. IP6 plus inositol enhances the anticancer effect of conventional chemotherapy, controls cancer metastases, and improves the quality of life, as shown in a pilot clinical trial. The data strongly argue for the use of IP6 plus inositol in our strategies for cancer prevention and treatment. However, the effectiveness and safety of IP6 plus inositol at therapeutic doses needs to be determined in phase I and phase II clinical trials in humans.

Plant foods and brain aging: a critical appraisal.

In the 21st century, human aging will be one of the biggest challenges for most societies throughout the world. The decline in human fitness is a typical hallmark of the aging process. Aside from the cardiovascular system, the brain most often suffers significantly from the life-long impact of stressors, such as reactive oxygen and nitrogen species. Oxytosis, i.e. oxidative stress-induced cell death, has been identified to play a major role in the development and onset of chronic diseases. Foods, especially of plant origin, are rich in antioxidants and numerous in vivo data suggest that a diet rich in fruits and vegetables supports the maintenance of animal and human health. These beneficial effects also extend to the central nervous system, which, due to the presence of the blood-brain barrier, tightly controls the influx of metabolites and nutrients. In earlier studies the impact of antioxidant vitamins, such as alpha-tocopherol and ascorbic acid, on brain health has been of interest. Recently, the focus moved to assessing the potential of unsaturated fatty acids and secondary plant metabolites, particularly of polyphenols, to act as neuroprotectants. Considerable experimental evidence suggests that polyphenols and other plant-derived bioactivities affect animal and human brain function not only by directly lowering oxidative stress load but also by modulating various signal transduction pathways.

Protection against cancer by dietary IP6 and inositol.

Inositol hexaphosphate (IP(6)) is a naturally occurring polyphosphorylated carbohydrate, abundantly present in many plant sources and in certain high-fiber diets, such as cereals and legumes. In addition to being found in plants, IP(6) is contained in almost all mammalian cells, although in much smaller amounts, where it is important in regulating vital cellular functions such as signal transduction, cell proliferation, and differentiation. For a long time IP(6) has been recognized as a natural antioxidant. Recently IP(6) has received much attention for its role in cancer prevention and control of experimental tumor growth, progression, and metastasis. In addition, IP(6) possesses other significant benefits for human health, such as the ability to enhance immune system, prevent pathological calcification and kidney stone formation, lower elevated serum cholesterol, and reduce pathological platelet activity. In this review we show the efficacy and discuss some of the molecular mechanisms that govern the action of this dietary agent. Exogenously administered IP(6) is rapidly taken up into cells and dephosphorylated to lower inositol phosphates, which further affect signal transduction pathways resulting in cell cycle arrest. A striking anticancer action of IP(6) was demonstrated in different experimental models. In addition to reducing cell proliferation, IP(6) also induces differentiation of malignant cells. Enhanced immunity and antioxidant properties also contribute to tumor cell destruction. Preliminary studies in humans show that IP(6) and inositol, the precursor molecule of IP(6), appear to enhance the anticancer effect of conventional chemotherapy, control cancer metastases, and improve quality of life. Because it is abundantly present in regular diet, efficiently absorbed from the gastrointestinal tract, and safe, IP(6) + inositol holds great promise in our strategies for cancer prevention and therapy. There is clearly enough evidence to justify the initiation of full-scale clinical trials in humans.

Molecular pathways for cancer chemoprevention by dietary phytochemicals.

Interest in dietary phytochemicals for potential cancer chemoprevention has increased substantially. Screening dietary compounds for chemopreventive activity however, requires a systematic and wide-ranging approach to encompass the complexity of carcinogenesis. We present some of the molecular pathways that underpin the broad biological processes involved in carcinogenesis. Oxidative stress, inflammation, and the evasion of apoptosis are important biological mechanisms by which carcinogenesis occurs. Subsequently, antioxidant, anti-inflammatory, and pro-apoptotic activity represent important activities for preventing, suppressing, or reversing the development of carcinogenesis. Ultimately, these mechanisms of action may provide a useful basis for screening novel phytochemicals for chemopreventive activity. In this review, we identify the important molecular processes that may be targeted in routine screenings of dietary phytochemicals to ultimately select the most effective potential candidates for cancer chemoprevention.

Impact of dietary shift to higher-antioxidant foods in COPD: a randomised trial.

Chronic obstructive pulmonary disease (COPD) is characterised by increased oxidative stress. Dietary factors, such as ample consumption of foods rich in antioxidants, such as fruit and vegetables, might have beneficial effects in COPD patients. The association between dietary shift to foods rich in antioxidants and lung function in COPD was investigated in a 3-yr prospective study. A total of 120 COPD patients were randomised to follow either a diet based on increased consumption of fresh fruit and vegetables (intervention group (IG)) or a free diet (control group (CG)). The mean consumption of foods containing antioxidants was higher in the IG than in the CG throughout the study period (p<0.05). The relationship between consumption of foods rich in antioxidants and percentage predicted forced expiratory volume in 1 s was assessed using a general linear model for repeated measures; the two groups overall were different in time (p = 0.03), with the IG showing a better outcome. In investigating the effect of several confounders (sex, age, smoking status, comorbid conditions and exacerbation) of group response over time, nonsignificant interactions were found between confounders, group and time. These findings suggest that a dietary shift to higher-antioxidant food intake may be associated with improvement in lung function, and, in this respect, dietary interventions might be considered in COPD management.

Berry fruits for cancer prevention: current status and future prospects.

Overwhelming evidence suggests that edible small and soft-fleshed berry fruits may have beneficial effects against several types of human cancers. The anticancer potential of berries has been related, at least in part, to a multitude of bioactive phytochemicals that these colorful fruits contain, including polyphenols (flavonoids, proanthocyanidins, ellagitannins, gallotannins, phenolic acids), stilbenoids, lignans, and triterpenoids. Studies show that the anticancer effects of berry bioactives are partially mediated through their abilities to counteract, reduce, and also repair damage resulting from oxidative stress and inflammation. In addition, berry bioactives also regulate carcinogen and xenobiotic metabolizing enzymes, various transcription and growth factors, inflammatory cytokines, and subcellular signaling pathways of cancer cell proliferation, apoptosis, and tumor angiogenesis. Berry phytochemicals may also potentially sensitize tumor cells to chemotherapeutic agents by inhibiting pathways that lead to treatment resistance, and berry fruit consumption may provide protection from therapy-associated toxicities. Although a wide variety of berry fruits are consumed worldwide, this paper focuses on those commonly consumed in North America, namely, blackberries, black raspberries, blueberries, cranberries, red raspberries, and strawberries. In addition, a large body of studies on singly purified berry bioactives is available, but this paper focuses on studies of "whole berries" per se, that is, as berry extracts and purified fractions, juices, and freeze-dried powders. Potential mechanisms of anticancer action and bioavailability of berry phenolics, as well as gaps in knowledge and recommendations for future berry research, are also briefly discussed.

Diallyl sulfide inhibits PhIP-induced DNA strand breaks in normal human breast epithelial cells.

Heterocyclic amines (HCAs) are formed when meat products such as beef, chicken, pork and fish are cooked at high temperatures. The most abundant HCA found in the human diet is 2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine (PhIP). PhIP causes mammary carcinomas in female rats and mice, and is associated with an increased risk of developing colon, breast, and prostate cancer in humans. PhIP is metabolized by cytochrome P-450s producing N-OH-PhIP. The N-OH-PhIP can be esterified by phase II enzymes forming an arylnitrenium ion that binds to DNA causing adducts. Furthermore, N-OH-PhIP may be reduced by cytochrome b5 reductase producing superoxide anions and hydroxyl radicals causing DNA strand breaks. Diallyl sulfide (DAS) has been shown to prevent cancer in several animal models, presumably by metabolic modulation. We hypothesize that PhIP produces reactive oxygen species causing DNA strand breaks and that DAS will inhibit the formation of PhIP induced DNA strand breaks. To test this hypothesis we treated normal breast epithelial (MCF-10A) cells with PhIP, DAS and a combination of PhIP and DAS. The detection of lipid peroxides was used as a surrogate for ROS. Lipid peroxides were detected using a PeroxiDetect kit (Sigma). PhIP increased the production of lipid peroxides and DAS decreased the PhIP-induced peroxidation by 47%. To determine if PhIP causes DNA strand breaks in MCF-10A cells, cells were treated for 3, 6, 9, and 24 h with PhIP (100 microM), DAS (100 microM) and a combination of PhIP (100 microM) and DAS (100 microM). DNA strand breaks were evaluated using the Comet assay. PhIP produced DNA strand breaks in a dose- and time-dependent fashion. We have shown that DAS inhibits PhIP-induced DNA strand breaks by inhibiting the production of reactive oxygen species. Therefore, we propose that DAS can prevent PhIP-induced breast cancer.

Fruit, Vegetable and Antioxidant Intakes are Lower in Older Adults with Depression

Studies have shown an association between depression and both antioxidant levels and oxidant stress, but generally have not included intakes of antioxidants and antioxidant-rich fruits and vegetables. The present study examined the cross-sectional associations between clinically-diagnosed depression and intakes of antioxidants, fruits and vegetables in a cohort of older adults. Antioxidant, fruit and vegetable intakes were assessed in 278 elderly participants (144 with depression, 134 without depression) using a Block 1998 food frequency questionnaire, which was administered between 1999 and 2007. All participants were age 60 years or over. Vitamin C, lutein and cryptoxanthin intakes were significantly lower among depressed individuals than in comparison participants (p<0.05). In addition, fruit and vegetable consumption, a primary determinant of antioxidant intake, was lower in depressed individuals. In multivariable models, controlling for age, sex, education, vascular comorbidity score, body mass index, total dietary fat, and alcohol, vitamin C, cryptoxanthin, fruits and vegetables remained significant. Antioxidants from dietary supplements were not associated with depression. Antioxidant, fruit and vegetable intakes were lower in individuals with late-life depression than in comparison participants. These associations may partially explain the elevated risk of cardiovascular disease among older depressed individuals. In addition, these findings point to the importance of antioxidant food sources rather than dietary supplements.

Advanced Glycation End Products in Foods and a Practical Guide to Their Reduction in the Diet

Modern diets are largely heat-processed and as a result contain high levels of advanced glycation end products (AGEs). Dietary advanced glycation end products (dAGEs) are known to contribute to increased oxidant stress and inflammation, which are linked to the recent epidemics of diabetes and cardiovascular disease. This report significantly expands the available dAGE database, validates the dAGE testing methodology, compares cooking procedures and inhibitory agents on new dAGE formation, and introduces practical approaches for reducing dAGE consumption in daily life. Based on the findings, dry heat promotes new dAGE formation by >10- to 100-fold above the uncooked state across food categories. Animal-derived foods that are high in fat and protein are generally AGE-rich and prone to new AGE formation during cooking. In contrast, carbohydrate-rich foods such as vegetables, fruits, whole grains, and milk contain relatively few AGEs, even after cooking. The formation of new dAGEs during cooking was prevented by the AGE inhibitory compound aminoguanidine and significantly reduced by cooking with moist heat, using shorter cooking times, cooking at lower temperatures, and by use of acidic ingredients such as lemon juice or vinegar. The new dAGE database provides a valuable instrument for estimating dAGE intake and for guiding food choices to reduce dAGE intake.

Effect of fat and carbohydrate consumption on endothelial function.

Consumption of a meal high in monounsaturated fat was associated with acute impairment of endothelial function when compared with a carbohydrate-rich meal. Such a divergent response in endothelial function may be important in the modulation of vascular function in health and disease.

Mediterranean diet and non enzymatic antioxidant capacity in the PREDIMED study: evidence for a mechanism of antioxidant tuning.

BACKGROUND AND AIMS: The intake of antioxidant-rich foods may increase the blood levels of non enzymatic antioxidant capacity (NEAC). NEAC takes into account all antioxidants from food and synergistic effects between them. We examined the effect of a 1-year intervention with Mediterranean diet on plasma NEAC and assessed whether it was related to baseline NEAC levels. METHODS AND RESULTS: Five hundred sixty-four participants at high cardiovascular risk were randomly selected from the PREDIMED (Prevención con DIeta MEDiterránea) Study, a large 3-arm randomized clinical trial. Blood NEAC levels were measured at baseline and after 1-year of dietary intervention with 1) a Mediterranean diet supplemented with virgin olive oil (MED + VOO); 2) a Mediterranean diet supplemented with nuts (MED + nuts), or 3) a control low-fat diet. Plasma NEAC was analyzed using FRAP (ferric reducing antioxidant potential) and TRAP (total radical-trapping antioxidant parameter) assays. Plasma FRAP levels increased after 1-year of intervention with MED + VOO [72.0 μmol/L (95% CI, 34.2-109.9)] and MED + nuts [48.9 μmol/L (24.3-73.5)], but not after the control low-fat diet [13.9 μmol/L (-11.9 to 39.8)]. Participants in the lowest quartile of plasma FRAP at baseline significantly increased their levels after any intervention, while those in the highest quartile decreased. Similar results occurred with TRAP levels. CONCLUSIONS: This study shows that a 1-year of MED diet intervention increases plasma TAC level in subjects at high risk for cardiovascular disease. Moreover, the effectiveness of dietary supplementation with antioxidants may be related to baseline levels of plasma NEAC. © 2013 Elsevier B.V. All rights reserved.

Effects of a high-fat meal on pulmonary function in healthy subjects.

Obesity has important health consequences, including elevating risk for heart disease, diabetes, and cancer. A high-fat diet is known to contribute to obesity. Little is known regarding the effect of a high-fat diet on pulmonary function, despite the dramatic increase in the prevalence of respiratory ailments (e.g., asthma). The purpose of our study was to determine whether a high-fat meal (HFM) would increase airway inflammation and decrease pulmonary function in healthy subjects. Pulmonary function tests (PFT) (forced expiratory volume in 1-s, forced vital capacity, forced expiratory flow at 25-75% of vital capacity) and exhaled nitric oxide (eNO; airway inflammation) were performed in 20 healthy (10 men, 10 women), inactive subjects (age 21.9 +/- 0.4 years) pre and 2 h post HFM (1 g fat/1 kg body weight; 74.2 +/- 4.1 g fat). Total cholesterol, triglycerides, and C-reactive protein (CRP; systemic inflammation) were determined via a venous blood sample pre and post HFM. Body composition was measured via dual energy X-ray absorptiometry. The HFM significantly increased total cholesterol by 4 +/- 1%, and triglycerides by 93 +/- 3%. ENO also increased (p < 0.05) due to the HFM by 19 +/- 1% (pre 17.2 +/- 1.6; post 20.6 +/- 1.7 ppb). ENO and triglycerides were significantly related at baseline and post-HFM (r = 0.82, 0.72 respectively). Despite the increased eNO, PFT or CRP did not change (p > 0.05) with the HFM. These results demonstrate that a HFM, which leads to significant increases in total cholesterol, and especially triglycerides, increases exhaled NO. This suggests that a high-fat diet may contribute to chronic inflammatory diseases of the airway and lung.

Laboratory, Epidemiological, and Human Intervention Studies Show That Tea (Camellia sinensis) May Be Useful in the Prevention of Obesity

Tea (Camellia sinensis, Theaceae) and tea polyphenols have been studied for the prevention of chronic diseases, including obesity. Obesity currently affects >20% of adults in the United States and is a risk factor for chronic diseases such as type II diabetes, cardiovascular disease, and cancer. Given this increasing public health concern, the use of dietary agents for the prevention of obesity would be of tremendous benefit. Whereas many laboratory studies have demonstrated the potential efficacy of green or black tea for the prevention of obesity, the underlying mechanisms remain unclear. The results of human intervention studies are mixed and the role of caffeine has not been clearly established. Finally, there is emerging evidence that high doses of tea polyphenols may have adverse side effects. Given that the results of scientific studies on dietary components, including tea polyphenols, are often translated into dietary supplements, understanding the potential toxicities of the tea polyphenols is critical to understanding their potential usefulness in preventing obesity. In this review, we will critically evaluate the evidence for the prevention of obesity by tea, discuss the relevance of proposed mechanisms in light of tea polyphenol bioavailability, and review the reports concerning the toxic effects of high doses of tea polyphenols and the implication that this has for the potential use of tea for the prevention of obesity. We hope that this review will expose areas for further study and encourage research on this important public health issue.

Neuroprotective effects of citrus flavonoids.

Recent attention has been given to the influence of dietary factors on health and mental well-being. Oxidative stress is associated with many diseases including neurodegenerative disorders. Dietary flavonoids exert cardioprotective, chemopreventive, and neuroprotective effects. The biological activities of flavonoids have been attributed to their antioxidant, anti-inflammatory, and signaling properties. A clear understanding of the mechanisms of action, as either antioxidants or signaling molecules, is crucial for the application of flavonoids as interventions in neurodegeneration and as brain foods. Citrus flavonoids exert little adverse effect and have low or no cytotoxicity to healthy, normal cells. The main citrus flavonoids can also traverse the blood-brain barrier; hence, they are promising candidates for intervention in neurodegeneration and as constituents in brain foods. In this review, we discuss the bioactivity, multiple neuroprotection mechanisms, and antioxidant and signaling properties of citrus flavonoids. Receptor-mediated neuroprotective actions and parallel signaling pathways are also explored. Finally, the induction of cellular defense proteins against oxidative stress and neurotoxicity by hesperetin, a main and widespread citrus flavonoid, are also discussed. It is suggested that citrus fruits, which are rich in abundant sources of hesperetin and other flavonoids, are promising for the development of general food-based neuroprotection and brain foods.

High ACAT1 expression in estrogen receptor negative basal-like breast cancer cells is associated with LDL-induced proliferation.

The specific role of dietary fat in breast cancer progression is unclear, although a low-fat diet was associated with decreased recurrence of estrogen receptor alpha negative (ER(-)) breast cancer. ER(-) basal-like MDA-MB-231 and MDA-MB-436 breast cancer cell lines contained a greater number of cytoplasmic lipid droplets compared to luminal ER(+) MCF-7 cells. Therefore, we studied lipid storage functions in these cells. Both triacylglycerol and cholesteryl ester (CE) concentrations were higher in the ER(-) cells, but the ability to synthesize CE distinguished the two types of breast cancer cells. Higher baseline, oleic acid- and LDL-stimulated CE concentrations were found in ER(-) compared to ER(+) cells. The differences corresponded to greater mRNA and protein levels of acyl-CoA:cholesterol acyltransferase 1 (ACAT1), higher ACAT activity, higher caveolin-1 protein levels, greater LDL uptake, and lower de novo cholesterol synthesis in ER(-) cells. Human LDL stimulated proliferation of ER(-) MDA-MB-231 cells, but had little effect on proliferation of ER(+) MCF-7 cells. The functional significance of these findings was demonstrated by the observation that the ACAT inhibitor CP-113,818 reduced proliferation of breast cancer cells, and specifically reduced LDL-induced proliferation of ER(-) cells. Taken together, our studies show that a greater ability to take up, store and utilize exogenous cholesterol confers a proliferative advantage to basal-like ER(-) breast cancer cells. Differences in lipid uptake and storage capability may at least partially explain the differential effect of a low-fat diet on human breast cancer recurrence.

"Towards an even healthier Mediterranean diet".

Dietary guidelines to promote good health are usually based on foods, nutrients, and dietary patterns predictive of chronic disease risk in epidemiologic studies. However, sound nutritional recommendations for cardiovascular prevention should be based on the results of large randomized clinical trials with "hard" end-points as the main outcome. Such evidence has been obtained for the Mediterranean diet from the PREDIMED (Prevención con Dieta Mediterránea) trial and the Lyon Heart Study. The traditional Mediterranean diet was that found in olive growing areas of Crete, Greece, and Southern Italy in the late 1950s. Their major characteristics include: a) a high consumption of cereals, legumes, nuts, vegetables, and fruits; b) a relatively high-fat consumption, mostly provided by olive oil; c) moderate to high fish consumption; d) poultry and dairy products consumed in moderate to small amounts; e) low consumption of red meats, and meat products; and f) moderate alcohol intake, usually in the form of red wine. However, these protective effects of the traditional Mediterranean diet may be even greater if we upgrade the health effects of this dietary pattern changing the common olive oil used for extra-virgin olive oil, increasing the consumption of nuts, fatty fish and whole grain cereals, reducing sodium intake, and maintaining a moderate consumption of wine with meals. © 2013 Elsevier B.V. All rights reserved.

Phenolic content of virgin olive oil improves ischemic reactive hyperemia in hypercholesterolemic patients.

OBJECTIVES: The goal of this study was to evaluate the effects of the phenolic content of virgin olive oil on endothelial reactivity. BACKGROUND: Endothelial-dependent vasodilatation is impaired during the postprandial state, and oxidative stress could play a key role in its development. METHODS: Twenty-one hypercholesterolemic volunteers received two breakfasts, using a randomized sequential crossover design. Both arms received the same olive oil, but one had its phenolic acid content reduced from 400 to 80 ppm. Ischemic reactive hyperemia (IRH) was measured with a laser-Doppler procedure at baseline and 2 h and 4 h after oil intake. Postprandial plasma concentrations of lipid fractions, lipoperoxides (LPO), 8-epi prostaglandin-F(2alpha), and nitrates/nitrites (NO(x)) were obtained at baseline and after 2 h of the fat meal. RESULTS: The intake of the polyphenol-rich breakfast was associated with an improvement in endothelial function, as well as a greater increase in concentrations of NO(x) (p < 0.001) and a lower increase in LPO (p < 0.005) and 8-epi prostaglandin-F2alpha (p < 0.001) than the ones induced by the low polyphenol fat meal. A positive correlation was found to exist between NO(x) and enhanced endothelial function at the second hour (r = 0.669; p < 0.01). Furthermore, a negative correlation was found between IRH and LPO (r = -0.203; p < 0.05) and 8-epi prostaglandin-F2alpha levels (r = -0.440; p < 0.05). CONCLUSIONS: A meal containing high-phenolic virgin olive oil improves ischemic reactive hyperemia during the postprandial state. This phenomenon might be mediated via reduction in oxidative stress and the increase of nitric oxide metabolites.