The Kuna people of the San Blas islands, off the coast of Panama, have a rate of heart disease that is nine times less than that of mainland Panamanians. The reason? The Kuna drink plenty of a beverage made with generous proportions of cocoa, which is unusually rich in flavanols that help preserve the healthy function of blood vessels. Maintaining youthful blood vessels lowers risk of high blood pressure, type 2 diabetes, kidney disease and dementia.