May 27, 2008 -- A cup of hot cocoa may seem like a no-no for people with diabetes, but the beverage may actually serve up a healthy dose of prevention and ward off heart disease, the leading cause of diabetes-related death.
New research published in the Journal of the American College of Cardiology provides substantial evidence that compounds in cocoa called flavonols improve the function and overall health of blood vessels. Unhealthy blood vessels are a leading cause of cardiovascular complications in people with diabetes.
Flavonols are naturally occurring plant compounds found in chocolate, red wine, and certain fruits and vegetables. A growing body of evidence suggests that cocoa flavonols have circulatory health benefits.
For the study, Malte Kelm, MD, a professor and chairman of cardiology, pulmonology and vascular medicine at the University Hospital Aachen and the Technical University Aachen, in Aachen, Germany, and colleagues examined the effect of a specially made flavonol-rich cocoa on patients with stable, treated type 2 diabetes.
The study participants randomly received cocoa containing either 25 milligrams or 321 milligrams of flavonol per serving. They drank the cocoa three times a day for 30 days. Researchers calculated each patient's blood vessel function before and after cocoa consumption at the start of the study and on days 8 and 30, using a combination of ultrasound images and blood pressure measurements.
Patients who drank the high-flavonol cocoa for one month had their blood vessel function improve from severely impaired to normal. Drinking the low-dose flavanol cocoa did not result in any significant changes in blood vessel function.
Researchers caution that the high-dose flavonol cocoa used in their study greatly exceeds the typical U.S. dietary intake of 20 to 100 milligrams daily, and you can't buy the extra-strength version in stores. Rather, they are optimistic that flavonol-containing diets offer an innovative approach to preventing heart disease.
"This research focuses on what's at the true heart of the discussion on 'healthy chocolate' -- it's about cocoa flavonols, the naturally occurring compounds in cocoa," Kelm writes. "While more research is needed, our results demonstrate that dietary flavonols might have an important impact as part of a healthy diet in the prevention of cardiovascular complications in diabetic patients."
In an accompanying editorial, Umberto Campia, MD, calls the study "important and thought-provoking," adding that "this is the foundation we need for doing a much larger prospective study that looks at the effect of cocoa flavonols not just on endothelial function, but also on the risk of heart attack, stroke, and other serious forms of cardiovascular disease."