Cocoa May Benefit Heart Health

COLOGNE, Germany--Two research letters published in the Aug. 27 issue of The Journal of the American Medical Association (JAMA) (290, 8:1029-31, 2003) (www.jama.com) suggest various constituents of cocoa beans have beneficial impacts on cardiovascular health.

In the first study, researchers from the University of Cologne, Germany, conducted a randomized crossover trial using 13 healthy individuals with mild hypertension. Participants consumed a 3-oz. dark chocolate bar (containing 500 mg of cocoa polyphenols) or white chocolate bar (with no polyphenols) daily for two weeks. Systolic blood pressure was reduced an average 5.1 mm Hg and diastolic blood pressure was down 1.8 mm Hg in the dark versus white chocolate group.

Dirk Taubert, M.D., Ph.D., the lead researcher, said it is likely the plant polyphenols in cocoa solids are responsible for the blood pressure reduction. "We have shown that some of the cocoa phenols are capable of dilating isolated arterial vessels and releasing nitric oxide; others have shown these polyphenols are absorbed by humans," he said. "We think isolated polyphenols from chocolate should have the same effects as the chocolate."

The second study had researchers from Heinrich-Heine-Universitat in Dusseldorf, Germany, investigating the effects of cocoa drinks rich in flavan-3-ols, a subclass of polyphenols, which have been shown to increase the activity of nitric oxide synthase. Twenty participants received 100 mL of cocoa drinks with high or low levels of flavon-3-ols on two consecutive days. Researchers found ingestion of cocoa with high levels of flavon-3-ols significantly increased flow-mediated dilation and nitric oxide bioactivity. This change may account for the polyphenols' mechanism of action in benefiting cardiovascular health.