See: Chocolate. This form of chocolate contains relatively low levels of sugar and is very rich and sometimes bitter in flavour.
Cocoa is rich in flavanols, and via this chemical it has shown to decrease insulin resistance, enhance insulin sensitivity, decrease blood pressure, decrease risk of cardiovascular disease and alleviate other cardiovascular disease-associated ailments. Though, despite the benefits of cocoa, many of the foods containing large amounts of chocolate are often heavy laden with fat and sugar, making excessive chocolate consumption a concern.
See: Cocoa Powder
The Journal of Clinical Hypertension
Critical Reviews in Food Science and Nutrition