Dark cocoa compounds, reduce blood pressure

18 August ScienceDaily

Compounds in cocoa may help to reduce blood pressure, according to a new systematic review in The Cochrane Library. The researchers reviewed evidence from short-term trials in which participants were given dark chocolate or cocoa powder daily and found that their blood pressure dropped slightly compared to a control group.

Cocoa contains compounds called flavanols, thought to be responsible for the formation of nitric oxide in the body.

Nitric oxide causes blood vessel walls to relax and open wider, thereby reducing blood pressure.

The link between cocoa and blood pressure stems from the discovery that the indigenous people of San Blas Island in Central American, who drink flavanol-rich cocoa drinks every day, have normal blood pressure regardless of age.

However, flavanol concentrations in cocoa and chocolate products vary according to cocoa processing procedures and types of chocolate, so it is difficult to establish the optimal dosage for an effect. To investigate the effect of flavanols on blood pressure, the researchers reviewed data from trials in which people consumed dark chocolate or cocoa powder containing between 30-1080 mg of flavanols in 3-100 g of chocolate each day.

Altogether, 856 people were involved in 20 trials lasting 2-8 weeks, or in one case, 18 weeks. Flavanol-rich chocolate or cocoa powder reduced blood pressure on average by 2-3 mm Hg.

“Although we don’t yet have evidence for any sustained decrease in blood pressure, the small reduction we saw over the short term might complement other treatment options and might contribute to reducing the risk of cardiovascular disease,” said lead researcher Karin Ried of the National Institute of Integrative Medicine in Melbourne, Australia, who worked with colleagues at the University of Adelaide.