Effect of Grape Consumption on Biomarkers of Endothelial and Cardiovascular Health

Abstract

Polyphenols have been associated with cardio‐protective benefits, however causal mechanisms remain elusive. This randomized, double‐blind, crossover study examines acute and longer‐term effects of grape consumption on biomarkers of endothelial and cardiovascular health. It was hypothesized that polyphenol‐rich grape consumption would protect against diet‐induced elevations and long‐term impairment in biomarkers of endothelial dysfunction during the acute postprandial period and after 4 weeks respectively. Twenty obese (BMI 37.0±9.9) but otherwise healthy adults were provided with isocaloric sachets of freeze‐dried whole grape powder (grape) (1 60g sachet/day=297mg polyphenol) and placebo (1 60g sachet/day=0mg polyphenol) for daily consumption, each treatment for 4 weeks separated by 2 week washout. To examine acute effects, postprandial blood samples were collected at 0, 1, 3 and 5 hours following a high fat high carbohydrate (HFHC) meal challenge and grape or placebo consumption. Longer‐term effects were examined by fasted blood samples collected on the last day of each 4‐week intervention. HDL increased (p<0.05) after 4 week grape consumption, but no other significant changes in lipids or blood glucose were noted between groups. Data analyzed by repeated measures, 2‐way ANOVA, showed that PAI‐1 and MCP‐1 were significantly elevated in plasma after HFHC challenge (p<0.05). However, no significant differences in plasma sICAM, sVCAM, ET‐1, PAI‐1 or MCP‐1 were detected between grape and placebo treatments after HFHC challenge or 4‐week intervention. Grape consumption has some beneficial effects on markers of cardiovascular health.Supported by California Table Grape Commission and USDA CRIS CA‐S*‐NTR‐6316‐H