With a complete lack of imagination, at least one person in my family normally receives a chocolate gift from me each Christmas.
Should I find myself uninspired again this year, maybe I can convince a recipient of some good quality dark chocolate, that I am also thinking of their heart, improving their brain performance, reducing their emotional stress or even protecting their skin?! Read on to find out why.
Potential cardiovascular health benefits of consuming chocolate high in cocoa flavanols (a class of flavonoids) have been known for some time. These include lowering blood pressure, reducing LDL cholesterol, and improving endothelial function among other things. [There are many references in our Nutrition and Food Sciences Database, for example see refs 1 and 2]. In fact, on the back of this research, chocolate maker Barry Callebaut has produced a number of chocolate products containing Acticoa, a cocoa powder with a high concentration of cocoa flavanols that, it claims, can help maintain cardiovascular health.
Last year, researchers from Oxford and Norway reported that chocolate can improve brain performance. They examined the relationship between cognitive performance and the intake of chocolate, wine, and tea (all containing flavonoids) in 2,031 people aged between 70 and 74. They found that participants who consumed chocolate, wine, or tea had significantly better mean cognitive test scores and lower prevalence of poor cognitive performance than those who did not. Their findings are reported in the Journal of Nutrition3.
The results of a clinical trial recently published in Journal of Proteome Research, suggests that dark chocolate may also help reduce stress. Researchers identified reductions in stress hormones and other stress-related biochemical changes in volunteers who rated themselves as highly stressed and ate dark chocolate for two weeks. "The study provides strong evidence that a daily consumption of 40 grams during a period of 2 weeks is sufficient to modify the metabolism of healthy human volunteers," the scientists say4.
Another study, just published in the Journal of Cosmetic Dermatology, suggests that eating chocolate can protect the skin from UV light5. Researchers evaluated the photoprotective potential of chocolate consumption in 30 healthy subjects, comparing a conventional dark chocolate to a specially produced chocolate with preserved high flavanol (HF) levels. While consumption of the conventional chocolate had no beneficial effect on the skin, consumption of the high flavanol chocolate conferred significant protection from harmful UV effects.
The fact that conventional chocolate had no beneficial effect is a bit of a disappointment – it seems that purchasing a random dark chocolate may not be good enough to back up my Christmas health promises! Indeed, much of the research about chocolate's health benefits appears to involve specially formulated high-flavanol chocolate or unsweetened cocoa. During chocolate making, many of the procedures can have a significant influence on the flavanol content. While the % cacao of a chocolate will tell you how much of the total content of ingredients are derived from the cacao bean, this is not always a reliable indication of the flavanol content – this can vary depending on recipe, cacao bean selection, handling and processing.
The good news is that with increasing research into the health benefits of flavanols, chocolate companies are beginning to see if there are ways of producing popular products whilst maintaining flavanol levels. Mars and Nestle have both been heavily involved in cocoa research. The Hershey Company (and collaborators) has just published the results of a study comparing the flavanol content of U.S. chocolate and cocoa-containing products6. The company says that it is trying to improve the measurement of flavanols in products, recognising that this is increasingly important for studying the potential health benefits of cocoa and chocolate and providing information to consumers.
Of course, despite all this promising news about dark chocolate, there is always the fat and sugar to think about! However, by choosing dark, rather than milk chocolate, we may find that we end up eating less of it – in a small trial researchers at the University of Copenhagen found that dark chocolate gives more of a feeling of satiety than milk chocolate and lessens cravings for sweet, salty and fatty foods. A theory I'm happy to test!
1. The vasculoprotective effects of flavonoid-rich cocoa and chocolate. Engler, M. B.; Engler, M. M. Nutrition Research 2004 Vol. 24 No. 9 pp. 695-706
2. Cocoa polyphenols and inflammatory mediators. Sies, H.; Schewe, T.; Heiss, C.; Kelm, M. American Journal of Clinical Nutrition 2005 pp. 304S-312S
3. Intake of Flavonoid-Rich Wine, Tea, and Chocolate by Elderly Men and Women Is Associated with Better Cognitive Test Performance. Eha Nurk, Helga Refsum, Christian A. Drevon, Grethe S. Tell, Harald A. Nygaard, Knut Engedal and A. David Smith. Journal of Nutrition 2009 Vol. 139, No. 1, pp. 120-127
4. Metabolic Effects of Dark Chocolate Consumption on Energy, Gut Microbiota, and Stress-Related Metabolism in Free-Living Subjects. Francois-Pierre J. Martin, Serge Rezzi, Emma Peré-Trepat, Beate Kamlage, Sebastiano Collino, Edgar Leibold, Jorgen Kastler, Dietrich Rein, Laurent B. Fay and Sunil Kochhar Journal of Proteome Research, published (web) October 7, 2009
5. Eating chocolate can significantly protect the skin from UV light. Stefanie Williams, Slobodanka Tamburic, Carmel Lally. Journal of Cosmetic Dermatology (2009) vol. 8, no. 3, pp. 169-173
6. Survey of Commercially Available Chocolate- and Cocoa-Containing Products in the United States. 2. Comparison of Flavan-3-ol Content with Nonfat Cocoa Solids, Total Polyphenols, and Percent Cacao. Kenneth B. Miller, W. Jeffrey Hurst, Nancy Flannigan, Boxin Ou, C. Y. Lee, Nancy Smith and David A. Stuart. Journal of Agricultural and Food Chemistry 2009, 57 (19), pp. 9169-9180