Chocolate is a good source of magnesium, copper, iron and zinc. It also contains polyphenols (an antioxidant also found in tea and red wine) that have been associated with a decreased risk of coronary disease. An average chocolate bar contains about the same amount of antioxidants as a 5-ounce glass of red wine.
A daily serving of dark chocolate, which contains more antioxidants than milk chocolate, can also help lower blood pressure and improve insulin resistance according to a joint study between Tufts University in Boston and the University of L’Aquila in Italy. The findings do not suggest that people with high blood pressure consume dark chocolate in lieu of taking their prescribed medication, but that the flavonoids in dark chocolate may have a positive effect on blood pressure and insulin resistance.