When investigators tracked chocolate's cardiovascular benefits for up to ten years, the trends were...heartening. Of 31,000 Swedish women, those who said they ate chocolate once or twice a week had a 32 percent lower risk of heart failure than abstainers. While science can't prove that cocoa gets all the credit, its flavanols may deter platelets from clumping together to form deadly clots. But—and here's a big one—most of us prefer milk chocolate to the darker stuff, and all that excess sugar every day can eventually outweigh the benefits. The lesson is to eat the treat only in its leanest, most potent forms: Cocoa or dark chocolate that's high in flavanol, low in sugar and fat. Which, to some, is bittersweet news.
Next: Good chocolate, bad chocolate and how to tell the difference