There's real science behind dark chocolate counting as health food. "Dark chocolate has one of the highest flavonoid profiles of any food," says Lamm. You know flavonoids — these antioxidants fight cell damage resulting from disease and aging. Research has also linked chocolate with a decrease in blood pressure and better memory recall. Just stick to a square or two a day, or no more than 100 calories, and make sure it's at least 70-percent cacao, says Lamm, which indicates a higher antioxidant level.