Research published this month suggests that some cocoa and chocolate products have a very high flavanol content, a factor which makes them good at protecting the body against cardiovascular disease.Flavanols are natural compounds found in a variety of foods including tea and red wine as well as cocoa, and research has shown that they appear to enhance the production of a hormone-like substance called nitric oxide from the inside wall of arteries. Nitric oxide can help improve the function of the arterial lining - called the endothelium - in healthy subjects and also in those with heart disease.
Writing in the current issue of the British Journal of Cardiology (BJC), Dr Norman Hollenberg, Professor of Medicine at Brigham and Women's Hospital, Boston, said: "Endothelial dysfunction is widely accepted as an important element in cardiovascular risk. While we know many things that reduce endothelial function (e.g. smoking), there are few agents or approaches that improve endothelial function consistently.
"The striking influence of flavanol-rich cocoa on nitric oxide-dependent endothelial function offers promise of a new approach to therapy."
Cardiovascular diseases remain the number one killer in developed countries, caused by a process called atherosclerosis which invariably begins in early childhood and gradually leads to 'furring-up' and blockages in the heart's coronary arteries.
Prevention, through good eating habits and lifestyle, is one of the best ways to avoid cardiovascular disease. There has been growing interest since the early 1990s in the potential benefits of dietary flavanols, both to delay the development of coronary heart disease and reduce its mortality.
Some researchers have been cautious about suggesting chocolate as a heart-healthy food because of concerns about an increase in the intake of unhealthy saturated fats and a higher likelihood of obesity. But Hollenberg's team was more positive: "Provided total fat intake does not exceed the recommended levels, there is no reason to believe that consumption of chocolate would represent an increased risk to health and, if the chocolate has a high flavanol content, it may contribute cardiovascular health benefits," they contend.
The scientists did, however, draw attention to the fact that the amount of flavanols in finished food products depended on the origin, post-harvest handling and processing of the flavanol-containing ingredient - in other words all chocolate is not created equal. Chocolate beverages, for example, make little if any contribution to flavanol intake due to their ingredient processing techniques, while dark chocolate products generally contain more flavanols than milk chocolate on a weight basis, due to dilution of cocoa solids.