Acute Consumption of Flavanol-Rich Cocoa and the Reversal of Endothelial Dysfunction in Smokers

• Published in: Journal of the American College of Cardiology Vol. 46; no. 7; pp. 1276 - 1283
• Main Authors: Heiss, Christian, Kleinbongard, Petra, Dejam, Andrè, Perré, Sandra, Schroeter, Hagen, Sies, Helmut, Kelm, Malte
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 04-10-2005; Elsevier Science; Elsevier Limited
• Subjects: Adult; Atherosclerosis; Beverages; Biological activity; Biological and medical sciences; Cacao; Cardiology; Cardiology. Vascular system; Cardiovascular disease; Consumption; Coronary vessels; Cross-Over Studies; Double-Blind Method; Endothelium; Endothelium, Vascular - drug effects; Endothelium, Vascular - physiopathology; Female; Flavonoids - pharmacology; Food; Free radicals; Heart attacks; Humans; Male; Medical sciences; Metabolites; Nitric oxide; Nitric Oxide - blood; Plasma; Smoking; Smoking - blood; Smoking - physiopathology; Studies; Tobacco, tobacco smoking; Toxicology; GTN; LFCD; RXNO; NOS; FMD; HFCD; Consumption; Smoker; Dysfunction; Acute; Tobacco smoking; Endothelial dysfunction; Circulatory system; Cardiology; Phlebology; Endothelium
• ISSN: 0735-1097; 1558-3597
• DOI: 10.1016/j.jacc.2005.06.055

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.
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.
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.
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.
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.