Grape Polyphenols Reduce Blood Pressure and Increase Flow-Mediated Vasodilation in Men with Metabolic Syndrome

• Published in: The Journal of nutrition Vol. 142; no. 9; pp. 1626 - 1632
• Main Authors: BARONA, Jacqueline, ARISTIZABAL, Juan C, BLESSO, Christopher N, VOLEK, Jeff S, LUZ FERNANDEZ, Maria
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Society for Nutrition 01.09.2012
• Subjects: Adult; Aged; Biological and medical sciences; Biomarkers - blood; Blood Pressure - drug effects; Brachial Artery - drug effects; Brachial Artery - physiology; Cross-Over Studies; Endothelium, Vascular - drug effects; Endothelium, Vascular - physiology; Feeding. Feeding behavior; Freeze Drying; Fundamental and applied biological sciences. Psychology; Humans; Intercellular Adhesion Molecule-1 - blood; Male; Metabolic Syndrome - drug therapy; Middle Aged; Nitrates - blood; Nitrites - blood; Placebos; Polyphenols - administration & dosage; Vascular Cell Adhesion Molecule-1 - blood; Vasculitis - drug therapy; Vasodilation - drug effects; Vasodilation - physiology; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Vitis - chemistry; Endocrinopathy; Human; Fruit; Nutrition; Metabolic diseases; Cardiovascular disease; Metabolic syndrome; Vasodilation; Micronutrient; Vasomotricity; Polyphenol; Grape; Proanthocyanidin; Blood pressure; Hemodynamics
• ISSN: 0022-3166; 1541-6100
• DOI: 10.3945/jn.112.162743

We evaluated the effects of grape polyphenols in individuals classified with metabolic syndrome (MetS). Men (n = 24) aged 30-70 y were randomly assigned to consume either a freeze-dried grape polyphenol powder (GRAPE) or a placebo for 30 d in a double-blind, crossover design, separated by a 3-wk washout period. Participants were asked to maintain their usual diet and physical activity during the study and abstain from consuming polyphenol-rich foods. MetS criteria including blood pressure (BP) and markers of vascular endothelial function including brachial artery flow-mediated vasodilation (FMD), plasma total nitrite + nitrate (NOx) to estimate NO production, plasma soluble intercellular adhesion molecule-1 (sICAM-1), and soluble vascular cell adhesion molecule-1 (sVCAM-1) were measured at the end of each dietary period. Systolic BP (P < 0.0025) and plasma sICAM-1 concentrations (P < 0.025) were lower, whereas the FMD response was higher (P < 0.0001), during the GRAPE compared with the placebo period. In addition, changes in sVCAM-1 concentrations between periods were positively correlated with changes in systolic BP (r = 0.45; P < 0.05). Although NOx concentrations did not differ between periods, changes in systolic BP were negatively correlated with changes in NOx concentrations (r = -0.44; P < 0.05), indicating the vasodilating properties of NO. Other MetS variables did not differ between the GRAPE and placebo periods. These results suggest that GRAPE polyphenols may potentiate vasorelaxation and reduce BP and circulating cell adhesion molecules, resulting in improvements in vascular function.