title: Acute consumption of flavanol-rich cocoa and the reversal of endothelial dysfunction in smokers.
abstract: OBJECTIVE
  This study was designed to assess the effect of flavanol-rich food on the circulating pool of bioactive nitric oxide (NO) and endothelial dysfunction in smokers.
  
  
  BACKGROUND
  Studies suggest that smoking-related vascular disease is caused by impaired NO synthesis and that diets rich in flavanols can increase bioactive NO in plasma.
  
  
  METHODS
  In smokers (n = 11), the effects of flavanol-rich cocoa on circulating NO species in plasma (RXNO) measured by reductive gas-phase chemiluminescence and endothelial function as assessed by flow-mediated dilation (FMD) were characterized in a dose-finding study orally administering cocoa containing 88 to 370 mg flavanols and in a randomized double-blind crossover study using 100 ml cocoa drink with high (176 to 185 mg) or low (<11 mg) flavanol content on two separate days. In addition to cocoa drink, ascorbic acid and NO-synthase inhibitor L-NMMA (n = 4) were applied.
  
  
  RESULTS
  There were significant increases in RXNO (21 +/- 3 nmol/l to 29 +/- 5 nmol/l) and FMD (4.5 +/- 0.8% to 6.9 +/- 0.9%, each p < 0.05) at 2 h after ingestion of 176 to 185 mg flavanols, a dose potentially exerting maximal effects. These changes correlated with increases in flavanol metabolites. Cocoa-associated increases in RXNO and FMD were reversed by L-NMMA. Ascorbic acid had no effect.
  
  
  CONCLUSIONS
  The circulating pool of bioactive NO and endothelium-dependent vasodilation is acutely increased in smokers following the oral ingestion of a flavanol-rich cocoa drink. The increase in circulating NO pool may contribute to beneficial vascular health effects of flavanol-rich food.
authors.affiliation: Institute for Biochemistry and Molecular Biology I, Heinrich-Heine-University, Duesseldorf, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Heiss
authors.forename: Petra
authors.initials: P
authors.lastname: Kleinbongard
authors.forename: Andrè
authors.initials: A
authors.lastname: Dejam
authors.forename: Sandra
authors.initials: S
authors.lastname: Perré
authors.forename: Hagen
authors.initials: H
authors.lastname: Schroeter
authors.forename: Helmut
authors.initials: H
authors.lastname: Sies
authors.forename: Malte
authors.initials: M
authors.lastname: Kelm
mesh_terms: D000328:Adult; D001628:Beverages; D002099:Cacao; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000503:physiopathology*; D005260:Female; D005419:Flavonoids / Q000494:pharmacology*; D006801:Humans; D008297:Male; D009569:Nitric Oxide / Q000097:blood; D012907:Smoking / Q000097:blood / Q000503:physiopathology*
chemical_list: D005419:Flavonoids; D009569:Nitric Oxide; C404987:flavan-3-ol