A new study reveals the chemical in chocolate that produces known heart-healthy benefits.
The research found that epicatechin, one of a group of chemicals known as flavanols, is directly linked to improved circulation and other hallmarks of cardiovascular health.
The discovery was detailed in the Jan. 16 online issue of the Proceedings of the National Academy of Sciences.
"Although previous studies strongly indicated that some flavanol-rich foods, such as wine, tea and cocoa can offer cardiovascular health benefits, we have been able to demonstrate a direct relationship between the intake of certain flavanols present in cocoa, their absorption into the circulation and their effects on cardiovascular function in humans," said biochemist Hagen Schroeter of the University of California, Davis.
The study relied on volunteers from the Kuna Indians, who live on the San Blas islands off the coast of Panama. High blood pressure and other signs of cardiovascular disease are rare among the Kuna. And they are known to consume large amounts of flavanol-rich cocoa—three to four cups a day.
Previous studies found that Kuna who migrated to the suburbs of Panama City on the mainland drink only about four cups of cocoa per week and do not enjoy the same level of cardiovascular health.
The islanders have twice the level of urinary nitric oxide, a chemical associated with healthy flow of blood through the arteries. And those who drank cocoa with more flavanols had higher levels of nitric oxide.
Also, higher levels of epicatechin in the bloodstream were accompanied by improved blood flow. Lab tests showed that flavanols allow vascular tissue to relax.
Finally, tests showed that pure epicatechin consumed by people had much the same effect as flavanol-rich cocoa.
"The results of this study provide direct proof that epicatechin is, at least in part, responsible for the beneficial vascular effects that are observed after the consumption of certain flavanol-rich cocoas," Schroeter said.
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