***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: 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 sample s 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 The consumption of cocoa and dark chocolate is associated with a lower risk of CVD , and improvements in endothelial function may mediate this relationship . Less is known about the effects of cocoa/chocolate on the augmentation index ( AI ) , a measure of vascular stiffness and vascular tone in the peripheral arterioles . We enrolled thirty middle-aged , overweight adults in a r and omised , placebo-controlled , 4-week , cross-over study . During the active treatment ( cocoa ) period , the participants consumed 37 g/d of dark chocolate and a sugar-free cocoa beverage ( total cocoa = 22 g/d , total flavanols ( TF ) = 814 mg/d ) . Colour-matched controls included a low-flavanol chocolate bar and a cocoa-free beverage with no added sugar ( TF = 3 mg/d ) . Treatments were matched for total fat , saturated fat , carbohydrates and protein . The cocoa treatment significantly increased the basal diameter and peak diameter of the brachial artery by 6 % ( + 2 mm ) and basal blood flow volume by 22 % . Substantial decreases in the AI , a measure of arterial stiffness , were observed in only women . Flow-mediated dilation and the reactive hyperaemia index remained unchanged . The consumption of cocoa had no effect on fasting blood measures , while the control treatment increased fasting insulin concentration and insulin resistance ( P= 0·01 ) . Fasting blood pressure ( BP ) remained unchanged , although the acute consumption of cocoa  increased resting BP by 4 mmHg . In summary , the high-flavanol cocoa and dark chocolate treatment was associated with enhanced vasodilation in both conduit and resistance arteries and was accompanied by significant reductions in arterial stiffness in women Epidemiological studies indicate that habitual coffee consumption lowers the risk of diabetes and cardiovascular diseases . Postpr and ial hyperglycemia is a direct and independent risk factor for cardiovascular diseases . We previously demonstrated that coffee polyphenol ingestion increased secretion of Glucagon-like peptide 1 ( GLP-1 ) , which has been shown to exhibit anti-diabetic and cardiovascular effects . We hypothesized coffee polyphenol consumption may improve postpr and ial hyperglycemia and vascular endothelial function by increasing GLP-1 release and /or reducing oxidative stress . To examine this hypothesis , we conducted a r and omized , acute , crossover , intervention study in healthy male adults , measuring blood parameters and flow-mediated dilation ( FMD ) after ingestion of a meal with or without coffee polyphenol extract ( CPE ) .  Nineteen subjects consumed a test meal with either a placebo- or CPE-containing beverage .  Blood biomarkers and FMD were measured at fasting and up to 180 minutes postpr and ially . The CPE beverage led to a significantly lower peak postpr and ial increase in blood glucose and diacron-reactive oxygen metabolite , and significantly higher postpr and ial FMD than the placebo beverage . Postpr and ial blood GLP-1 increase tended to be higher after ingestion of the CPE beverage , compared with placebo . Subclass analysis revealed that the CPE beverage significantly improved postpr and ial blood GLP-1 response and reduced blood glucose increase in the subjects with a lower insulinogenic index . Correlation analysis showed postpr and ial FMD was negatively associated with blood glucose increase after ingestion of the CPE beverage . In conclusion , these results suggest that coffee polyphenol consumption improves postpr and ial hyperglycemia and vascular endothelial function , which is associated with increased GLP-1 secretion and decreased oxidative stress in healthy humans There is much epidemiological evidence suggesting a reduced risk of development of type 2 diabetes ( T2D ) in habitual coffee drinkers , however to date there have been few longer-term interventions , directly examining the effects of coffee intake on glucose and lipid metabolism . Previous studies may be confounded by inter-individual variation in caffeine metabolism . Specifically , the rs762551 SNP in the CYP1A2 gene has been demonstrated to influence caffeine metabolism , with carriers of the C allele considered to be of a ' slow ' metaboliser phenotype . This study investigated the effects of regular coffee intake on markers of glucose and lipid metabolism in coffee-naïve individuals , with novel analysis by rs762551 genotype . Participants were r and omised to either a coffee group ( n 19 ) who consumed four cups/d instant coffee for 12 weeks or a control group ( n 8) who  remained coffee/caffeine free .  Venous blood sample s were taken pre- and post-intervention . Primary analysis revealed no significant differences between groups . Analysis of the coffee group by genotype revealed several differences . Before coffee intake , the AC genotype ( ' slow ' caffeine metabolisers , n 9 ) displayed higher baseline glucose and NEFA than the AA genotype ( ' fast ' caffeine metabolisers , n 10 , P<0·05 ) . Post-intervention , reduced postpr and ial glycaemia and reduced NEFA suppression were observed in the AC genotype , with the opposite result observed in the AA genotype ( P<0·05 ) . These observed differences between genotypes warrant further investigation and indicate there may be no one-size-fits-all recommendation with regard to coffee drinking and T2D risk BACKGROUND Accumulating evidence suggests that certain dietary polyphenols have biological effects in the small intestine that alter the pattern of glucose uptake . Their effects , however , on glucose tolerance in humans are unknown . OBJECTIVE The objective was to investigate whether chlorogenic acids in coffee modulate glucose uptake and gastrointestinal hormone and insulin secretion in humans . DESIGN In a 3-way , r and omized , crossover study , 9 healthy fasted volunteers consumed 25 g glucose in either 400 mL water ( control ) or 400 mL caffeinated or decaffeinated coffee ( equivalent to 2.5 mmol chlorogenic acid/L ) . Blood sample s were taken frequently over the following 3 h. RESULTS Glucose and insulin concentrations tended to be higher in the first 30 min after caffeinated coffee consumption than after consumption of decaffeinated coffee or the control ( P < 0.05 for total and incremental area under the curve for glucose and insulin ) . Glucose-dependent insulinotropic polypeptide secretion decreased throughout the experimental period ( P < 0.005 ) , and glucagon-like peptide 1 secretion increased 0 - 120 min postpr and ially ( P < 0.01 ) after decaffeinated coffee consumption compared with the control . Glucose and insulin profiles were consistent with the known metabolic effects of caffeine . However , the gastrointestinal hormone profiles were consistent with delayed intestinal glucose absorption . CONCLUSIONS Differences in plasma glucose , insulin , and gastrointestinal hormone profiles further confirm the potent biological action of caffeine and suggest that chlorogenic acid might have an antagonistic effect on glucose transport . Therefore , a novel function of some dietary phenols in humans may be to attenuate intestinal glucose absorption rates and shift the site of glucose absorption to more distal parts of the intestine BACKGROUND AND OBJECTIVES Obesity has become a public health problem and is a cause of some preventable illnesses . Among several methods for treating obesity , the use of food supplements is highly common . A commonly used food supplement is green coffee bean extract . The objective of this study was to evaluate the efficacy of green coffee bean extract combined with an energy-restricted diet on the body composition and serum adipocytokines in obese women . METHODS AND STUDY DESIGN In this r and omised clinical trial , 64 obese women aged 20 - 45 years were selected and divided into two groups : an intervention group ( receiving 400 mg green coffee bean extract for 8 weeks ) and control group ( receiving placebo ) . All participants were on an energy-restricted diet .  The body composition , leptin , adiponectin , lipid profile , free fatty acids ( FFAs ) , and fasting blood sugar were compared between the two groups . RESULTS We observed significant reductions in the body weight , body mass and fat mass indices , and waist-to-hip circumference ratio in both groups ; however , the decrease was higher in the intervention group . Moreover , serum total cholesterol , low-density lipoprotein , leptin , and plasma free fatty acids significantly decreased in the intervention group ( p<0.05 ) after adjustment for energy and fibre intake . The serum adiponectin concentration significantly increased in the intervention group ( p<0.05 ) . CONCLUSIONS Green coffee bean extract combined with an energy-restricted diet affects fat accumulation and lipid metabolism and is thus an inexpensive method for weight control in obese people Regular consumption of flavonoids may reduce the risk for CVD . However , the effects of individual flavonoids , for example , quercetin , remain unclear . The present study was undertaken to examine the effects of quercetin supplementation on blood pressure , lipid metabolism , markers of oxidative stress , inflammation , and body composition in an at-risk population of ninety-three overweight or obese subjects aged 25 - 65 years with metabolic syndrome traits . Subjects were r and omised to receive 150 mg quercetin/d in a double-blinded , placebo-controlled cross-over trial with 6-week treatment periods separated by a 5-week washout period . Mean fasting plasma quercetin concentrations increased from 71 to 269 nmol/l ( P < 0.001 ) during quercetin treatment . In contrast to placebo , quercetin decreased systolic blood pressure ( SBP ) by 2.6 mmHg ( P < 0.01 ) in the entire study group , by 2.9 mmHg ( P < 0.01 ) in the subgroup of hypertensive subjects and by 3.7 mmHg ( P < 0.001 ) in the subgroup of younger adults aged 25 - 50 years . Quercetin decreased serum HDL-cholesterol concentrations ( P < 0.001 ) , while total cholesterol , TAG and the LDL : HDL-cholesterol and TAG : HDL-cholesterol ratios were unaltered . Quercetin significantly decreased plasma concentrations of atherogenic oxidised LDL , but did not affect TNF-alpha and C-reactive protein when compared with placebo . Quercetin supplementation had no effects on nutritional status . Blood parameters of liver and kidney function , haematology and serum electrolytes did not reveal any adverse effects of quercetin . In conclusion , quercetin reduced SBP and plasma oxidised LDL concentrations in overweight subjects with a high-CVD risk phenotype . Our findings provide further evidence that quercetin may provide protection against CVD Chlorogenic acid has been described as a novel polyphenol with metabolic effects on glucose homeostasis . The aim of this study was to evaluate the effect of chlorogenic acid administration on glycemic control , insulin secretion , and insulin sensitivity in patients with impaired glucose tolerance ( IGT ) . A r and omized , double-blind , placebo-controlled clinical trial was performed in 30 patients with IGT ; 15 patients r and omly assigned to oral chlorogenic acid received 400 mg three times per day for 12 weeks , and the other 15 patients received placebo in the same way . Before and after the intervention , anthropometric and metabolic measurements , including fasting plasma glucose ( FPG ) , glycated hemoglobin A1c , and a lipid profile , were performed . Area under the curve of glucose and insulin as well as 
    Output:
    
Results demonstrated that health status is a potentially important effect modifier as RCTs with higher baseline cholesterol , blood pressure and glycaemia demonstrated greater overall effectiveness , which was also found in studies where specific subgroup analyses were performed .