title: Platelet reactivity in male smokers following the acute consumption of a flavanol-rich grapeseed extract.
abstract: 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.
authors.affiliation: Department of Family and Consumer Science, Sacramento City College, Sacramento, CA, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Polagruto
authors.forename: Heidrun B
authors.initials: HB
authors.lastname: Gross
authors.forename: Faranak
authors.initials: F
authors.lastname: Kamangar
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Kosuna
authors.forename: Buxiang
authors.initials: B
authors.lastname: Sun
authors.forename: Hajime
authors.initials: H
authors.lastname: Fujii
authors.forename: Carl L
authors.initials: CL
authors.lastname: Keen
authors.forename: Robert M
authors.initials: RM
authors.lastname: Hackman
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000328:Adult; D001792:Blood Platelets / Q000187:drug effects / Q000502:physiology*; D003094:Collagen / Q000494:pharmacology; D004311:Double-Blind Method; D004837:Epinephrine / Q000494:pharmacology; D005419:Flavonoids / Q000008:administration & dosage*; D005638:Fruit / Q000737:chemistry; D006487:Hemostasis / Q000187:drug effects; D006801:Humans; D008297:Male; D010919:Placebos; D010936:Plant Extracts / Q000008:administration & dosage*; D012639:Seeds / Q000737:chemistry*; D012907:Smoking / Q000097:blood*; D027843:Vitis / Q000737:chemistry*
chemical_list: D005419:Flavonoids; D010919:Placebos; D010936:Plant Extracts; D000244:Adenosine Diphosphate; D003094:Collagen; D004837:Epinephrine