Flavanol Rich Chocolate... The Sacred Secret! Dietary intake of a specific subclass of flavonoids known as flavanols has attracted increasing interest as a result of recent epidemiological mechanistic and human intervention studies suggesting potential beneficial cardiovascular effects. Among the wide variety of dietary flavanol sources, including apples, cranberries, purple grapes, red wine, and tea, some cocoas and chocolates can be extraordinarily rich in certain types of flavanols