***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: BACKGROUND Green tea polyphenols ( GTPs ) have significant antioxidant and antiinflammatory activities , and prior short‐term studies suggest that these compounds may improve photoaging skin . OBJECTIVES To evaluate the long‐term effects of oral GTPs on the clinical and histologic characteristics of photoaging skin . MATERIAL S AND METHODS Double‐blind , placebo‐controlled trial of 56 women aged 25 to 75 r and omized to 250 mg GTPs or placebo twice daily for 2 years . A blinded dermatologist scored the appearance of photodamaged facial skin at 0 , 6 , 12 , and 24 months . A blinded dermatopathologist scored the histologic characteristics of sun‐exposed arm skin at 0 and 24 months . RESULTS Clinical assessment of facial skin revealed that the GTP group had significant improvement in overall solar damage at 6 months ( p=.02 ) and significant improvement in erythema and telangiectasias at 12 months ( p=.02 ) . The placebo group did not have significant improvements in these parameters at 6 months or 12 months . There were no statistically significant differences in other photoaging parameters at 6 , 12 , or 24 months in the GTP or placebo groups . Histopathologic analysis of sunexposed arm skin showed no statistically significant difference in photoaging parameters in the GTP group or the placebo group at 24 months . CONCLUSIONS Long‐term supplementation with oral GTPs was not superior to placebo in improving clinical or histologic photoaging parameters after 24 months of use . Funding and material s for this study were provided by Nu Skin , Provo , Utah . Dale Kern is an employee of Nu Skin International Background Raisins are a significant source of dietary fiber and polyphenols , which may reduce cardiovascular disease ( CVD ) risk by affecting lipoprotein metabolism and inflammation . Walking represents a low intensity exercise intervention that may also reduce CVD risk . The purpose of this study was to determine the effects of consuming raisins , increasing steps walked , or a combination of these interventions on blood pressure , plasma lipids , glucose , insulin and inflammatory cytokines . Results Thirty-four men and postmenopausal women were matched for weight and gender and r and omly assigned to consume 1 cup raisins/d ( RAISIN ) , increase the amount of steps walked/d ( WALK ) or a combination of both interventions ( RAISINS + WALK ) . The subjects completed a 2 wk run-in period , followed by a 6 wk intervention . Systolic blood pressure was reduced for all subjects ( P = 0.008 ) . Plasma total cholesterol was decreased by 9.4 % for all subjects ( P < 0.005 ) , which was explained by a 13.7 % reduction in plasma LDL cholesterol ( LDL-C ) ( P < 0.001 ) . Plasma triglycerides ( TG ) concentrations were decreased by 19.5 % for WALK ( P < 0.05 for group effect ) . Plasma TNF-α was decreased from 3.5 ng/L to 2.1 ng/L for RAISIN ( P < 0.025 for time and group × time effect ) . All subjects had a reduction in plasma sICAM-1 ( P < 0.01 ) . Conclusion This research shows that simple lifestyle modifications such as adding raisins to the diet or increasing steps walked have distinct beneficial effects on CVD risk Epidemiologic studies indicated that tea consumption reduces the risk of cardiovascular disease . We assessed the effect of green or black tea consumption on resistance of low-density lipoprotein ( LDL ) to oxidation ex vivo and on serum lipid concentrations in healthy volunteers . In a 4-wk parallel comparison trial , 45 volunteers consumed 900 mL ( 6 cups ) mineral water , green tea , or black tea/d . Blood sample s drawn while subjects were fasting were obtained before and after the study . The effect on resistance of subsequently isolated LDL to oxidation of adding green or black tea extract to plasma was investigated in an in vitro experiment . Consumption of 900 mL ( 6 cups ) green or black tea/d did not affect serum lipid concentrations , resistance of LDL to oxidation , or markers of oxidative damage to lipids in vivo , although consumption of green tea slightly increased total antioxidant activity of plasma . The in vitro experiment showed that resistance of isolated LDL to oxidation increased only after incubation of plasma with very high amounts of green or black tea . These amounts , when converted to tea catechin concentrations , were much higher than those expected in vivo . We conclude that daily consumption of 900 mL ( 6 cups ) green or black tea/d for 4 wk had no effect on serum lipid concentrations or resistance of LDL to oxidation ex vivo . Future research should focus on mechanisms by which tea flavonoids may reduce the risk of cardiovascular disease other than by increasing the intrinsic antioxidant status of LDL BACKGROUND Patients treated with hemodialysis frequently experience cardiovascular complications attributed , among other causes , to dyslipidemia , increased oxidative stress , and inflammation . OBJECTIVE The aim of the study was to study the effects of dietary supplementation with concentrated red grape juice ( RGJ ) , a source of polyphenols , on lipoprotein profile , antioxidant capacity , LDL oxidation , and inflammatory biomarkers . DESIGN Twenty-six patients receiving hemodialysis and 15 healthy subjects were instructed to drink 100 mL RGJ/d for 14 d. Blood was drawn at baseline , twice during RGJ supplementation , and twice during the 6-mo follow-up period . As a control , 12 other r and omly recruited hemodialysis patients not receiving RGJ  were studied . Lipids , apolipoproteins , oxidized LDL , and antioxidant vitamins were measured in plasma . The bioavailability of RGJ polyphenols was assessed in healthy subjects . RESULTS The maximum plasma concentration of quercetin was achieved 3 h after RGJ ingestion , which indicates that supplement-derived polyphenols are rapidly absorbed . In both healthy subjects and hemodialysis patients , RGJ consumption increased the antioxidant capacity of plasma without affecting concentrations of uric acid or ascorbic acid ; reduced the concentration of oxidized LDL ; and increased the concentration of cholesterol-st and ardized alpha-tocopherol .  RGJ supplementation also caused a significant decrease in LDL-cholesterol and apolipoprotein B-100 concentrations , while increasing the concentrations of HDL cholesterol and apolipoprotein A-I. In a further study in hemodialysis patients , RGJ supplementation for 3 wk significantly reduced plasma monocyte chemoattractant protein 1 , an inflammatory biomarker associated with cardiovascular disease risk . CONCLUSION Dietary supplementation with concentrated RGJ improves the lipoprotein profile , reduces plasma concentrations of inflammatory biomarkers and oxidized LDL , and may favor a reduction in cardiovascular disease risk BACKGROUND Oxidative damage to lipids in vivo may be involved in the development of atherosclerosis and cancer . Onions and black tea are foods rich in flavonoids , predominantly the flavonoid quercetin , which is a potent in vitro inhibitor of membrane lipid peroxidation and LDL oxidation . OBJECTIVE Our objective was to investigate the effects of consuming a high-flavonoid ( HF ) diet enriched with onions and black tea on indexes of oxidative damage in vivo compared with a low-flavonoid ( LF ) diet . DESIGN Thirty-two healthy humans were studied in a r and omized crossover design . Indexes of oxidative damage used were plasma F2-isoprostanes ( a biomarker of lipid peroxidation in vivo ) and the titer of antibodies to malondialdehyde (MDA)-modified LDL . RESULTS There were no significant differences in the intake of macronutrients or assessed micronutrients , plasma F2-isoprostane concentrations , and MDA-LDL autoantibody titer between the HF and LF dietary treatments . In the men , however , plasma concentrations of the F2-isoprostane 8-epi-prostagl and in F2alpha were slightly higher after the HF treatment phase than after the LF treatment [ 0.31 + /- 0.029 nmol/L ( 111 + /- 10.4 ng/L ) compared with 0.26 + /- 0.022 nmol/L ( 92 + /- 7.8 ng/L ) ; P = 0.041 ] . In all subjects , plasma quercetin concentrations were significantly higher after the HF treatment phase than after the LF treatment : 221.6 + /- 37.4 nmol/L compared with less than the limit of detection of 66.2 nmol/L. CONCLUSION Flavonoid consumption in onions and tea had no significant effect on plasma F2-isoprostane concentrations and MDA-LDL autoantibody titer in this study and thus does not seem to inhibit lipid peroxidation in humans BACKGROUND Tea has been associated with a reduced risk of  cardiovascular disease .  One proposed mechanism of this risk reduction involves inhibition of lipoprotein oxidation in vivo by antioxidant polyphenolic compounds derived from tea . However , controlled interventions uniformly failed to show that ingestion of tea can inhibit LDL oxidation ex vivo . The absence of effects in previous studies may be due to the isolation of LDL particles from polyphenolic compounds that are present in the aqueous phase of serum . OBJECTIVE The objective of this study was to examine the acute effects of ingestion of black and green tea on ex vivo Cu(2+)-induced lipoprotein oxidation without prior isolation of lipoproteins from serum . DESIGN The acute effects of 4 hot drinks-green tea and black tea ( each at a dose equivalent to 4 st and ard cups ) , water matched to the teas for caffeine content , and water-were assessed in 20 healthy men by using a Latin-square design . The lag time to lipoprotein diene formation , slope of the propagation phase of the oxidation curve , and area under the oxidation curve were calculated . Urinary concentrations of 4-O-methylgallic acid were used as a marker of uptake and metabolism of polyphenolic compounds from tea . RESULTS Significant increases in urinary 4-O-methylgallic acid for black and green tea ( P < 0 . 0001 ) were observed . Caffeine did not significantly influence lipoprotein oxidation . Compared with the water control , there was a greater lag time for black tea ( 5.4 + /- 2.9 min ; P = 0.05 ) that was of borderline significance and a similar trend for green tea ( 4.4 + /- 2.8 min ; P = 0.17 ) . Slope and area under the oxidation curve were not altered . CONCLUSION Black tea has a mild acute effect on ex vivo lipoprotein oxidation in human serum . 2000;71:-7 Prospect i ve studies suggest that tea may protect against cardiovascular disease . A potential mechanism for such an effect involves inhibition of lipid peroxidation by polyphenolic antioxidants derived from tea . Our objective was to determine whether regular ingestion of tea could inhibit in vivo lipid peroxidation . Two controlled intervention studies assessed the effects of regular ingestion of tea on lipid peroxidation determined by measurement of urinary F(2)-isoprostane excretion . Study 1 : The effects of 1000 mL/d of green tea and black tea were compared with hot water containing caffeine in 13 subjects with elevated blood pressure using a r and omized 3-period ( 7 d each ) crossover design . Study 2 : The effects of 1250 mL/d of black tea were compared with hot water in 22 subjects with mildly raised serum total cholesterol concentrations using a r and omized 2-period ( 4 wk each ) crossover design . F(2)-isoprostane excretion was not altered after regular ingestion of green tea ( 273 + /- 48 pmol/mmol creatinine ) or black tea ( 274 + /- 39 pmol/mmol creatinine ) in comparison with hot water ( 263 + /- 47 pmol/mmol creatinine ; Study 1 ) , or by regular ingestion of black tea ( 334 + /- 71 pmol/mmol creatinine ) in comparison with hot water ( 355 + /- 75 pmol/mmol creatinine ; Study 2 ) . These results do not support the suggestion that polyphenolic antioxidants derived from tea inhibit in vivo lipid peroxidation To evaluate the effects of grape polyphenols on plasma lipids , inflammatory cytokines , and oxidative stress , 24 pre- and 20 postmenopausal women were r and omly assigned to consume 36 g of a lyophilized grape powder ( LGP ) or a placebo for 4 wk . The LGP consisted of 92 % carbohydrate and was rich in flavans , anthocyanins , quercetin , myricetin , kaempferol , and resveratrol . After a 3-wk washout period , subjects were assigned to the alternate treatment for an additional 4 wk . The placebo consisted of an equal ratio of fructose and dextrose and was similar in 
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Vitis vinifera L. showed promising results , but other trials should be performed in order to assessing the efficacy .
No studies were found on the leaves of Olea europea L. whereas more human trials are needed to assess the anti-inflammatory effect of olive oil .