Eating dark chocolate boosts the blood’s antioxidant power by 20%, according to research published in Nature magazine. The antioxidant in chocolate is called epicatechin. Milk chocolate is much less effective.
A study of older men in the Netherlands found eating the equivalent of a third of a dark chocolate bar (about 40g) a day may lower blood pressure and the risk of death.
Dark chocolate (but not milk chocolate or white chocolate) also appears to inhibit the aggregation of platelets, an early step in the formation of blood clots that can cause heart attack or stroke.
However, chocolate also contains sugar and fat, so while a little chocolate may be a good thing, a lot of chocolate may be too much of a good thing.