title: Flavanol-rich cocoa drink lowers plasma F(2)-isoprostane concentrations in humans.
abstract: Flavan-3-ols are potent antioxidants in vitro, but convincing evidence for antioxidant action in vivo is lacking. We examined whether an oxidative stress-mediated increase in plasma F(2)-isoprostanes is counteracted by a flavanol-rich cocoa beverage. Twenty volunteers were examined in a comparative randomized double-blind crossover design with respect to ingestion of high-flavanol cocoa drink (HFCD; 187 mg flavan-3-ols/100 ml) vs. low-flavanol cocoa drink (LFCD; 14 mg/100 ml). With 10 individuals, the treatment was combined with strenuous physical exercise. Total (esterified plus nonesterified) F(2)-isoprostanes were analyzed by GC/MS. LFCD caused a slight increase in the mean (+/- SEM) plasma concentrations of F(2)-isoprostanes 2 and 4 h after intake (2.16 +/- 0.19 nM at 4 h vs. 1.76 +/- 0.11 nM at 0 h, n = 10), which may be attributable to postprandial oxidative stress. This increase did not occur with HFCD (1.57 +/- 0.06 nM at 4 h vs. 1.65 +/- 0.10 nM at 0 h, n = 10). The difference in F(2)-isoprostanes 2 and 4 h after intake of HFCD vs. LFCD became statistically significant when the intake was combined with physical exercise (P < 0.01, ANOVA). We conclude that dietary flavanols, using cocoa drink as example, can lower the plasma level of F(2)-isoprostanes, indicators of in vivo lipid peroxidation.
authors.affiliation: Institut für Klinische Chemie und Pathobiochemie, Otto-von-Guericke-Universität Magdeburg, Germany.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Wiswedel
authors.forename: Daniela
authors.initials: D
authors.lastname: Hirsch
authors.forename: Siegfried
authors.initials: S
authors.lastname: Kropf
authors.forename: Martin
authors.initials: M
authors.lastname: Gruening
authors.forename: Eberhard
authors.initials: E
authors.lastname: Pfister
authors.forename: Tankred
authors.initials: T
authors.lastname: Schewe
authors.forename: Helmut
authors.initials: H
authors.lastname: Sies
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000032:analysis; D001628:Beverages; D002099:Cacao / Q000737:chemistry*; D002392:Catechin / Q000097:blood / Q000378:metabolism; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology; D028441:F2-Isoprostanes / Q000097:blood*; D005227:Fatty Acids / Q000032:analysis; D005419:Flavonoids / Q000008:administration & dosage* / Q000494:pharmacology*; D006801:Humans; D015227:Lipid Peroxidation; D008297:Male
chemical_list: D000975:Antioxidants; D028441:F2-Isoprostanes; D005227:Fatty Acids; D005419:Flavonoids; D002392:Catechin