Cardiovascular benefits of cocoa.
Activity of the angiotensin-converting enzyme (ACE)—a target for blood pressure medication—was significantly inhibited by dark chocolate containing 72% cocoa, with the degree of inhibition dependent upon the genotype of the human subjects, according to new findings published in the Journal of Cardiovascular Pharmacology. ACE inhibitors work by inhibiting the conversion of angiotensin I to the potent vasoconstrictor, angiotensin II, thereby improving blood flow and blood pressure.
The new study, led by scientists from the Faculty of Health Sciences at Linkoping University in Sweden, found that cocoa’s effect upon ACE activity was also related to ACE genotype, with ACE inhibition reduced by 21% in ACE I/I and 28% in ACE D/D three hours after consumption. The study deepens our understanding of the potential cardiovascular benefits of cocoa and the compounds it contains.
In terms of blood pressure, a meta-analysis by researchers from the University Hospital of Cologne found that consumption of cocoa had significant positive effects on hypertension. Writing in the Archives of Internal Medicine (2007, Vol. 167, pp. 626-634), the Cologne-based scientists stated: “The magnitude of the hypotensive effects of cocoa is clinically noteworthy; it is in the range that is usually achieved with monotherapy of beta-blockers or angiotensin-converting enzyme inhibitors.” The majority of science into the potential benefits of cocoa have revolved around cardiovascular benefits of the flavanols (also known as flavan-3-ols or catechins) and particularly the monomeric flavanol (-) epicatechin.
For the new study, Ingrid Persson and her co-workers recruited 16 volunteers aged between 20 and 45, and asked them to eat 75 grams of dark chocolate with 72% cocoa content every day for two weeks. Results showed a significant inhibition of ACE activity, with a reduction of about 18% observed between before and after the cocoa intake. Such a reduction is equivalent to those observed with antihypertensive medications, said the researchers. “Our results indicate that lifestyle changes, with the help of foods that contain high catechin and procyanidin content, prevent cardiovascular disease,” said Dr. Persson. Journal of Cardiovascular Pharmacology 57(1):44-50, 2011