May reduce heart disease risk

Dark chocolate compounds appear to be highly protective against LDL oxidation. In the long run, this should result in much less cholesterol accumulating in the arteries, lowering the risk of heart disease.

Several long-term observational studies, in fact, show a fairly significant improvement. In a 15-year study of 470 older men, cocoa was found to reduce the risk of death from heart disease by 50%. Another study found that eating chocolate twice a week reduced the risk of having calcified plaque in the arteries by 32%. Reduced chocolate consumption had no effect. Another study found that eating dark chocolate at least five times per week reduced the risk of heart disease by 57%. According to a 2017 clinical trial, subjects who consumed almonds with or without dark chocolate had lower LDL cholesterol levels.

Of course, because these four studies are observational, it's unclear whether the chocolate actually reduced the risk. However, because the biological process is known (lower blood pressure and oxidized LDL), it's possible that eating dark chocolate on a regular basis may reduce the risk of heart disease.