Hunter-gatherer Kuna Indians living on remote islands in Panama suffer remarkably less from hypertension and cardiovascular disease than those that have migrated to urban areas. They eat more fish and fruit, but they also have a notably high intake of cocoa which contains flavonoids such as epicatechin.
McCullough ML, Chevaux K, Jackson L, Preston M, Martinez G, Schmitz HH, Coletti C, Campos H, Hollenberg NK (2006). Hypertension, the Kuna, and the epidemiology of flavanols. Journal of Cardiovasular Pharmacology. 47 Suppl 2:S103-9; discussion 119-21.