Platelet reactivity in male smokers following the acute consumption of a flavanol-rich grapeseed extract

J Med Food. 2007 Dec;10(4):725-30. doi: 10.1089/jmf.2007.402.


Epidemiological studies suggest that a high dietary intake of flavanols, a subclass of flavonoids, is associated with reduced risk of vascular disease. Clinical studies have also shown that the consumption of certain flavanol-rich foods (e.g., cocoa, tea, red wine), as well as intake of the individual flavanol (-)-epicatechin, can result in improvement in a number of parameters associated with vascular disease, including improved endothelial function, reduced platelet reactivity, and reduced oxidative stress. The present study assessed the effects of a flavanol-rich supplement on platelet reactivity and plasma oxidant defense in a group of smokers, a population at an elevated risk for vascular disease. Male smokers were randomly assigned to a placebo (n = 10) or a flavanol-rich grapeseed extract (FRGSE; n = 13) group, and after an overnight fast, blood samples were collected before and at 1, 2, and 6 hours following consumption of the placebo or supplement. The FRGSE supplement, but not the placebo, significantly decreased ADP-stimulated platelet reactivity at 1, 2, and 6 hours following intake (P < .05) compared to baseline levels. Similarly, the supplement, but not the placebo, decreased epinephrine-stimulated platelet reactivity 2 hours following consumption. Plasma antioxidant capacity (total radical trapping antioxidant potential), lipid oxidation (plasma thiobarbituric acid-reactive substances), and serum uric acid concentrations were not affected in either group. Thus smokers may obtain some health benefits from the consumption of certain flavanol-rich foods, beverages, and supplements.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Diphosphate / pharmacology
  • Adult
  • Blood Platelets / drug effects
  • Blood Platelets / physiology*
  • Collagen / pharmacology
  • Double-Blind Method
  • Epinephrine / pharmacology
  • Flavonoids / administration & dosage*
  • Fruit / chemistry
  • Hemostasis / drug effects
  • Humans
  • Male
  • Placebos
  • Plant Extracts / administration & dosage*
  • Seeds / chemistry*
  • Smoking / blood*
  • Vitis / chemistry*


  • Flavonoids
  • Placebos
  • Plant Extracts
  • Adenosine Diphosphate
  • Collagen
  • Epinephrine