In recent years, large-scale epidemiological studies have shown that individuals whose diet includes dark chocolate have a lower risk of developing cardiovascular diseases than those who do not consume it. Other research has shown that chocolate contains flavonols, a subgroup of flavonoids, which may reduce the risk of cardiovascular diseases. However, it has not been clearly established how these flavonols could impact the body, particularly the heart. Nevertheless, new findings from studies conducted by Virginia Tech and Louisiana State University suggest that the protective role of chocolate in cardiovascular health may come from the fact that it is largely indigestible, meaning it is poorly or minimally absorbed by the body.
Scope of the Studies
Researchers from Louisiana State University arrived at this conclusion after reconstructing the human digestive system in glass containers. One container represented the stomach and small intestine, with their digestive enzymes, and the second replicated the environment of a large intestine colonized by microbial flora provided by human volunteers. Scientists then added cocoa powder to the container simulating the stomach. "The stomach" and "the small intestine" broke down and absorbed some elements of cocoa. While most of the flavonols previously identified in chocolate were digested this way, there was still a lot of undigested cocoa matter. Subsequently, the intestinal bacteria in the reconstructed colon further broke down the material into metabolites small enough to be absorbed into the bloodstream, thus participating in reducing cardiovascular inflammation. Finally, the undigested cocoa portion, mainly composed of fibers, began to ferment, releasing substances that improve cholesterol levels. More interestingly, it turns out that the intestinal bacteria that digested cocoa were probiotics (Lactobacillus). Their numbers seemed to increase after the introduction of cocoa into the digestive system, while less healthy bacteria such as staphylococci decreased in number.
These results are broadly consistent with those of Virginia Tech, published in March in the Journal of Agricultural and Food Chemistry. This study administered a high-fat diet to two groups of mice and differentiated it by adding flavonols or cocoa powder. The study's authors concluded that flavonols played a crucial role in preventing weight gain in mice that received flavonols.
Pending further studies on the subject and a deeper understanding of chocolate digestion and its properties, do not overindulge in chocolate! As you know, there is chocolate and there is chocolate! If you enjoy chocolate, you can reasonably consume dark chocolate with 70% cocoa content or higher to enjoy all its benefits. Other chocolates and derivative products often contain high amounts of sugars, milk, and other fats, and should be avoided!
Sources : Why Chocolate Is Good for Us, Gretchen Reynolds, édition du 27 Avril 2014 du New York Times Magazine.
(1) Impact of the Microbiome on Cocoa Polyphenolic Compounds. Maria Moore, Mfamara Goita, Dr. John W. Finley, Department of Nutrition and Food Science Louisiana State University. (2) J Agric Food Chem. 2014 Mar 12;62(10):2216-27. doi: 10.1021/jf500333y. Epub 2014 Mar 3.