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Sweet Medicine: The science of chocolate and health



Chocolate had used as medicine since its inception. The Aztec king Montezuma is said to have consume anywhere from 20 to 50 glasses in order to remain virile. In more recent times, scientists have been looking into whether there are some medical treasures hidden in this scrumptious treat. Naturally, scientists have been zooming in on what it is in chocolate that gives it its health benefits. Scientists now believe these compounds in chocolate, called flavanols, have antioxidant properties and could help treat a variety of conditions and fight a variety of diseases. This has led to a lot of good research being done. There have been studies done that look at chocolate’s impact in fighting heart disease, diabetes, and cancer[1]. There have been studies looking at chocolate’s effect on cognitive function, memory, and blood pressure.  However, before you run to the pantry to self-medicate with chocolate be forewarned; this research, like all medical research, in fact like all science, has caveats. This particular group of research has a good deal of caveats, though not every study has the exact same caveats. Those depend on the strengths and failings of each individual study.

There is one caveat though that applies to this entire group of research; all the chocolate in these studies is all dark chocolate, that is to say to that it is at least sixty percent cacao solids. Milk chocolate is not included and for good reason. US law states that chocolate only needs to contain ten percent cacao in order to legally qualify as chocolate, the rest is mainly sugar, fat, and a few other things such as milk. According to professor Carla Martin, lecturer at Harvard University and director of the Fine Cacao and Chocolate Institute, “A Hershey’s Kiss typically contains about, I think, 11 percent cacao content”. To put that in perspective, if you had a bar of typical milk chocolate that weighed one hundred grams (about the weight of an iPhone 5S[2]), then the actual amount of chocolate in the bar would be only about ten grams, or the weight of two nickels. The fact that milk chocolate has barely any actual chocolate means that milk chocolate has barely any of those cacao flavanols that are thought to provide the health benefits. Thus, anyone, scientist or otherwise, looking towards chocolate for health benefits has to look towards chocolate with a high cacao content.

Chocolate flavanols table
Figure 1


There are many pitfalls a research study can fall into. One of these is having a limited and/or small sample size.  Multiple studies on the effect of chocolate on health have had sample sizes of less than a couple hundred people. One such study, the Cocoa, Cognition, and Aging (CoCoA) Study had only ninety participants. The study found that regular cocoa flavanol consumption can reduce some measures of age-related cognitive dysfunction, but given such small sample size it is difficult to draw any large generalized conclusions for the general population, since there is a wide variety of differences across populations. Moreover, the CoCoA study limited their sample size in an attempt at prove clearer causation; because this was a study on aging all the participant were elderly, and the study also excluded Current smokers, habitual users of antioxidant supplements (including vitamins C and E), habitual consumers of chocolate or other cocoa products (daily consumption of any amount), or individuals prescribed medications known to have antioxidant properties (including statins and glitazones) or to interfere with cognitive functions (including benzodiazepines and antidepressants). This means for populations outside the participant group, the research has limited application, since the researcher did not look at how cocoa flavanol intake affects people with these additional variables. It has to be remembered that studies like this are jumping off point, they prove that there is something there that needs to be looked into, but further research is required in order to the proper applications and implications of the initial research.

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