According to researchers from the National Institute of Integrative Medicine in Melbourne and the University of Adelaide, dark chocolate and cocoa powder may help in lowering blood pressure. Flavanols, found in cocoa, red wine, grapes, apples and tea, is a compound thought to be responsible for the dip in blood pressure. These flavanols form nitric oxide within the body which causes blood vessel walls to become more wide and relaxed, causing the drop in blood pressure.
Researchers conducted trials in which people indulged in 30-1080 mg of flavanols in 3-100 g of chocolate each day. During these 20 trials taking place over 18 weeks, these participants, on average, experienced a blood pressure drop by 2-3 mm Hg.
Despite the fact that there is no affirmation regarding a sustained decrease in blood pressure, dark chocolate or cocoa powder does prove to have an effect short term and may even contribute to decreasing the risk of cardiovascular disease. Take it from the indigenous people of San Blas Island in Central America who, regardless of age, have normal blood pressure and consume cocoa drinks rich in flavanols everyday.
Long-term trials have yet to be completed in order to see how dark chocolate and cocoa powder influence the risk for cardiovascular disease or stroke.
Research also shows dark chocolate may help improve cognitive function in the brains of the elderly. A link was found between larger amounts of flavanols and improved levels in cognitive testing. Again, it is unclear whether or not this improved cognitive functioning is directly due to the flavanols found in cocoa or the secondary effect of enhanced heart health.
So go ahead, indulge. But make sure it's dark! Keep in mind, these flavanols are only found in dark chocolate due to the high cocoa content.