Polyphenol Intake in Elderly People Is Associated with Lipid Oxidative Damage

Dietary polyphenol intake, body composition and components of metabolic syndrome in a sample overweight and obese adults: a cross-sectional study

BACKGROUND

The health benefits of dietary polyphenol intake (DPI) including improved lipid profiles, blood pressure, insulin resistance, and reduced systemic inflammation has revealed previously. However, the results of numerous studies are not consistent and it seems that these health effects are attributed to some of DPI. In the current research, we evaluated the health benefits of DPI on metabolic markers and glycemic markers among overweight and obese individuals.

METHODS

In this cross-sectional study, 487 individuals with overweight and obesity were participated. Dietary intake was assessed by a Food Frequency Questionnaire (FFQ) and the amount of dietary polyphenol intake were calculated based on the information derived from Phenol-Explorer database ( www.phenolexplorer.eu/contents ). Bioelectrical impedance analysis (BIA) was used to measure body composition. Systolic and diastolic blood pressures were measured by sphygmomanometer. Biochemical assays including fasting blood sugar, insulin and serum lipids' concentrations were measured by enzymatic methods.

RESULTS

According to our results, males were more likely to be at the highest tertile of DPI (P = 0.04). Also, those at the highest tertile of DPI had higher fat free mass and physical activity level (P < 0.05). Lower TG level in highest tertile of DPI in crude model was also observed, but, it lost its significant threshold after adjustment for confounders. Subjects at the second tertile of DPI were more likely to have lower systolic blood pressure in the sex and age adjusted model [OR = 0.970; CI = 0.940-1.000; P = 0.049]. For other biochemical variables, no significant association was observed.

CONCLUSION

In the current study, total dietary polyphenol intake was associated with lower SBP among overweight and obese individuals. Further studies are warranted to better elucidate the observed results.

Effects of grape consumption on biomarkers of inflammation, endothelial function, and PBMC gene expression in obese subjects

This study investigated effects of grape consumption on biomarkers of cardiovascular health in obese participants in both postprandial and chronic settings. Twenty obese adults participated in this randomized, placebo controlled, double-blinded crossover trial. Participants were randomized to consume 60 g freeze-dried polyphenol-rich whole grape powder (GP) or placebo (PBO) followed by high fat high carbohydrate (HFHC) meal challenge. Following acute challenge, participants consumed their respective treatment daily for 4 weeks to determine effects of chronic consumption. Consumption of GP with HFHC meal significantly increased nuclear factor (erythroid-derived 2)-like 2 (NRF2) expression in peripheral blood mononuclear cells (PBMC) at 3 h (p < 0.05) and decreased plasma endothelin-1 (ET-1) concentration at 5 h (p < 0.05) after meal challenge compared with PBO. Following 4 weeks of daily GP consumption, soluble vascular cell adhesion molecule 1 (sVCAM-1) plasma concentration increased compared with PBO (p < 0.05), however baseline values differed between treatments. In conclusion, GP consumption resulted in decreased vasoconstrictor ET-1 concentration and increased gene expression related to oxidative stress defense following HFHC meal. Except for increase in sVCAM-1 concentration, 4 weeks of chronic GP consumption had little effect on cardiovascular biomarkers measured in this study. This trial was registered: clinicaltrials.gov NCT01674231.

Lychee pulp phenolics ameliorate hepatic lipid accumulation by reducing miR-33 and miR-122 expression in mice fed a high-fat diet

The repression of miR-33 and miR-122 is a possible molecular mechanism of the hypolipidemic effects of lychee pulp phenolics.

Dietary flavonoid intake, total antioxidant capacity and lipid oxidative damage: A cross-sectional study of Iranian women

OBJECTIVES

Although strong evidence supports the antioxidant potential of flavonoids in vitro, the effect of flavonoids at physiological concentrations on the overall antioxidant status in humans is inconsistent. The aim of this study was to examine cross-sectional associations between total flavonoid consumption, serum total antioxidant capacity (TAC), and malondialdehyde (MDA) levels in apparently healthy women.

METHODS

Through a multistage cluster sampling, 170 women ages 20 to 48 y were recruited. The usual dietary flavonoid intake was estimated using a semiquantitive food frequency questionnaire (FFQ) by matching food items with the US Department of Agriculture flavonoid databases. General linear models were used to compare the biochemical parameters across tertiles of flavonoid intakes.

RESULTS

As dietary anthocyanin intake rose from the lowest to the highest tertile, the multivariate-adjusted mean TAC concentrations significantly increased from 1.08 to 1.28 (Ptrend = 0.01). This association was still significant after adjustment for fruit and vegetable intake and antioxidant vitamins (Ptrend = 0.03). The highest tertile of total flavonoid intake and theaflavins had higher mean concentrations of TAC than did the lowest tertile, but there was no linear trend (P < 0.05). There were statistically significant positive relationships between dietary intake of grapes and eggplant as main food sources of anthocyanins and serum TAC (P = 0.02 and 0.04, respectively). No significant associations were found between MDA and flavonoids intakes (P > 0.05).

CONCLUSIONS

The findings of the present study support the attribution of anthocyanins to overall antioxidant status. However, further research is needed to confirm these observed associations.

Effect of grape and other berries on cardiovascular health

Cardiovascular disease is a leading cause of death globally. Many cardiovascular risk factors can be modified through lifestyle modification, including dietary patterns that emphasize daily consumption of a variety of fruits and vegetables. Recent observational and clinical studies suggest that flavonoids, especially those abundant in grapes and other berries, may be associated with health benefits, particularly cardiovascular benefits. Human clinical data support cardioprotective benefits of grapes through inhibition of platelet aggregation, decreased low-density lipoprotein (LDL) oxidation, reduction in oxidative stress and improvements in endothelial function. Emerging evidence suggests that grapes may also have a favorable effect on blood lipids, decrease inflammation and reduce blood pressure in certain populations. Studies to date have shown that berries can have a beneficial effect on reducing LDL oxidation. Limited data suggest that berries may have a favorable effect on endothelial health and blood pressure. This review summarizes the current literature on human clinical studies examining the cardioprotective benefits of grapes and berries. Collectively, these data support the recommendation to incorporate products made with grapes and other berries into a heart-healthy diet.