Cocoa contains a variety of chemicals, including antioxidants called flavonoids. It's not clear how these might work in the body, but they appear to relax the blood vessels. This could lead to lower blood pressure, and reduce inflammation and blockage of blood vessels. People most commonly use cocoa for heart disease and high blood pressure. It is also used for high cholesterol, memory, aging skin, and many other conditions, but there is no good scientific evidence to support these other uses.