First of all, due to the content of antioxidants in cocoa, which belong to the group of polyphenols. They help improve the functioning of small blood vessels in the brain. Polyphenols help normalize blood cholesterol levels, improve the condition of the cell wall, the rheological properties of blood, that is, maintaining it in a liquid state and preventing the formation of blood clots. After all, it is known that it is problems with blood vessels that most often become a risk factor for the development of dementia.