Chocolates dark secret

Posted on Tue, 8 Dec 09

Cocoa, the principle ingredient in chocolate, has been attributed to medicinal effects for millennia. But  how much cocoa is enough to benefit, and is this just a good excuse to eat chocolate?

Food of the gods  

Originally used by the ancient Incas, cocoa was considered a divine food. In fact the scientific name of the cocoa tree, Theobroma cacao, comes from the Greek words theo (god) and broma (drink). Recently research has discovered that acute consumption of chocolate has a number of health effects attributed to its naturally high concentration of polyphenols, a group of phytonutrients.

Sweet heart

The effects of cocoa are most pronounced in the cardiovascular system where it has the ability to increase a substance involved in the relaxation of blood vessels called nitric oxide. Enhancement of the ability of blood vessels to relax plays an important role in heart disease, type-2 diabetes and high blood pressure and not surprisingly human clinical studies suggest that cocoa can improve these conditions (1).  

Too much of a good thing

The high calorie content of commercially available chocolate may increase risk of weight gain and outweigh the benefits of chocolate in the long-term.  Most human studies have only examined short term consumption of chocolate at around 40-100 grams daily (up to 500 calories). However one report found that a relatively small amount of chocolate (6.3 grams providing 30 calories per day of dark chocolate) reduced blood pressure after 18 weeks suggesting that small amounts could form part of a healthy diet (2).

Commercial chocolate typically has a high sugar content which, apart from increasing risk of weight gain, dental carries and other chronic diseases, may also directly negate the beneficial effects of cocoa in the cardiovascular system (3). Low sugar products such as very dark chocolate should be preferred and pure cocoa, which can be used in cooking, has a low fat and sugar content.

References

1. Corti R, et al. Cocoa and Cardiovascular Health. Circulation, March 17, 2009; 119(10): 1433 - 1441.

2. Taubert D,et al. Effects of low habitual cocoa intake on blood pressure and bioactive nitric oxide: a randomized controlled trial. JAMA. 2007 Jul 4;298(1):49-60.

3. Faridi Z,et al. Acute dark chocolate and cocoa ingestion and endothelial function: a randomized controlled crossover trial. Am J Clin Nutr. 2008 Jul;88(1):58-63.