Chocolate Lowers Blood Pressure, Improves Cardiovascular Health

Pieces of chocolateFoods rich in cocoa, such as chocolate, may lower blood pressure and reduce the risk of coronary heart disease according to a study published in the journal Archives of Internal Medicine in 2006.

The study, conducted by Dutch researchers, used data from the Zutphen study to assess whether cocoa could reduce blood pressure and improve cardiovascular health. In total, 470 elderly men aged between 65 and 84 were used in the 15 year study which began in 1985.

The men were divided into three groups according to chocolate intake with the highest group averaging at least 2.25g of cocoa per day while the lowest group consumed less than 0.5g per day on average.

After adjusting for other factors such as BMI and age, the researchers found that compared to men in the lowest group for cocoa intake, the men in the highest group had systolic and diastolic blood pressures that were 3.1 and 2.0 mm Hg lower respectively.

The researchers also found that regular chocolate eaters were much less likely to die from cardiovascular causes such as heart disease and stroke. Men in the highest group for cocoa intake were half as likely to die during from cardiovascular disease during the study than men in the lowest group for cocoa consumption.

Interestingly, after adjusting these results for blood pressure, the men who ate the most cocoa were still less likely to die from cardiovascular disease meaning that the lower risk of cardiovascular death was not due to the lower blood pressures observed in the regular cocoa eaters but by some other mechanism.

The full results of the study can be found at the Archives of Internal Medicine website.

What makes this study surprising is that chocolate contains moderate amounts of caffeine, around 30mg per serving for milk chocolate and 60mg per serving for dark chocolate (50% cocoa solids). Caffeine by itself normally acts as a stimulant, increasing blood pressure in the short term.

It is thought that the flavanols found in chocolate are responsible for the cardiovascular benefits of cocoa. In particular, catechins and epicatechins which are found in cocoa, wine, and green tea leaves, are thought to be the most beneficial compounds. It is believed that catechins and epicatechins reduce the build up of plaques in the arteries and improve the function of the cells lining the blood vessels known as endothelial cells. Flavanols are also thought to reduce LDL cholesterol levels and improve blood flow throughout the body.