An interesting study clearly shows how the flavanols contained in chocolate, as well as fruits and most vegetables, can be so beneficial to your health. Even if you're a smoker...
Researchers compared the effect of flavanols on a dozen smokers participating in a double-blind study. Half were given a cocoa drink rich in flavanols, and the rest had a drink that tasted the same but had far fewer flavanols. The study measured the benefits to smokers because their blood vessels tend to respond poorly to changes in blood flow, possibly related to impairments in how nitric oxide sends signals to the inner lining (the endothelium) of blood vessels, a warning sign for cardiovascular disease.
Those who drank cocoa containing as much as 185 mgs of flavanols experienced significant increases in circulating nitric oxide and flow-mediated dilation. Moreover, the benefits disappeared when patients were given a drug that interferes with nitric oxide signaling.
One caveat: The cocoa drink used in the study was specially processed to retain much higher levels of flavanols than are typically found in commercially-available cocoa drinks.
These results certainly match a Greek study in which eating dark chocolate offered other heart-healthy benefits.
Journal of the American College of Cardiology, Vol. 46, No. 7, October 4, 2005: 1276-1283
EurekAlert September 28, 2005