A recent review in Circulation is published: Cocoa and Cardiovascular Health. It reviews the clinically relevant cardiovascular effects of cocoa, focusing on potential mechanisms involved in the response to cocoa and the potential clinical implications associated with its consumption.
Recently we discussed the possible ways chocolate protects the cardiovascular system in a post. In short you can see these mechanisms in the picture beneath, from this review.
Although still debated, a range of potential mechanisms through which flavanols and cocoa might exert their benefits on cardiovascular health have been proposed: activation of nitric oxide (NO) and antioxidant, antiinflammatory, and antiplatelet effects, which in turn might improve endothelial function, lipid levels, blood pressure, insulin resistance, and eventually clinical outcome
It is important to distinguish cocoa from chocolate, chocolate is cocoa combined with sugar, and eventually milk and other ingredients into a solid food product. Flavonoids are the part of cocoa important for health benefits. They can also be found in high concentrations in certain fruits and vegetables. In the context of human nutrition, certain teas, grape juice, wine, various berries, and especially cocoa represent noteworthy sources. Cocoa has the highest content of flavonoids compared to the other sources.
The highest plasma peak concentrations of flavanols are obtained 2 to 3 hours after ingestion of chocolate in a dose-dependent manner, and are still measurable after 8 hours. It is unclear whether the consumption of cocoa together with milk or as milk chocolate reduces the bio availability. Besides the fact that dark chocolate has far higher concentration of flavonoid compared to milk chocolate it is also noteworthy that manufacturing of chocolate can reduce flavonol concentration.
You will probably all know by now that Dr Shock is a fan of dark chocolate so he never misses an opportunity to promote the digestion of this divine essential nutrient. Precautions in its use are mandatory. The high caloric value of commercially available chocolate (about 500 kcal/100g) may induce weight gain, a risk factor for hypertension, dyslipidemia, and diabetes. Cocoa itself, unlike chocolate, can be recommended without hesitation because it is low in sugar and fat. The right daily dosage of cocoa or chocolate remains elusive, unfortunately.
As with the authors of this excellent review I will end with the wish for more research especially with dietary supplematation with flavonols, preferably as cocoa
……direct dietary supplementation with flavanols instead of chocolate consumption deserves further study. Indeed, protocols using epicatechin or other flavanoids specifically are now feasible and should clarify this question. At this point, recommending dietary supplementation with flavanols, similar to vitamins, appears problematic because potential prooxidative effects of large quantities cannot be excluded.
More research is needed meanwhile enjoy your cocoa.
Related posts on this blog:
Red Wine and Dark Chocolate for Vascular Health
Corti, R., Flammer, A., Hollenberg, N., & Luscher, T. (2009). Cocoa and Cardiovascular Health Circulation, 119 (10), 1433-1441 DOI: 10.1161/CIRCULATIONAHA.108.827022