2.2. Cocoa, Polyphenols and Cardiovascular Disease
Evidence based on epidemiological studies suggests that dietary flavonoids may play a critical role in the prevention of coronary heart disease (CHD).
Cocoa (Theobroma cacao) and its derived products, such as chocolate, represent a very rich source of dietary flavonoids, containing a higher content per serving than tea, red wine, legumes or fruits. The health benefits associated with cocoa consumption have been related to their protective effect mainly against cardiovascular diseases, but also in other diseases such as age-related cognitive decline.
Observational studies have shown that the Kuna Indian population from the San Blas Islands of Panama have very low rates of hypertension and cardiovascular disease, effects that have been related to their high intake of cocoa. Clinical trials have also evaluated the effects of cocoa intake on different cardiovascular risk factors.
Several studies have confirmed that cocoa intake reduces blood pressure in normotensive and hypertensive subjects. In fact, dark chocolate intake increases nitric oxide (NO) generation, which leads to vasodilatation, and reduces systolic and diastolic blood pressure by 2.77 mmHg and 2.20 mmHg, respectively, whereas white chocolate does not reduce blood pressure.
Another mechanism by which flavanols may lower blood pressure is by the inhibition of angiotensin-converting enzyme (ACE). In addition, cocoa intake improves lipid profile and insulin sensibility, reduces platelet activity and function, and ameliorates endothelial dysfunction. At least some of these other beneficial effects have also been attributed to anti-inflammatory and antioxidant activities of polyphenols contained in cocoa. Therefore, the addition of dark chocolate to a well-balanced healthy diet such as a Mediterranean diet, offers a palatable option to preventing cardiovascular disease.