A study presented at the 247th National Meeting & Exposition of the American Chemical Society (ACS) shows the exact reason why consuming dark chocolate has health benefits.
According to the researchers, certain bacteria in the stomach eat the chocolate and ferment it into anti-inflammatory compounds that are good for the heart.
"We found that there are two kinds of microbes in the gut: the 'good' ones and the 'bad' ones," explained Maria Moore, an undergraduate student at Louisiana State University and one of the study's researchers. "The good microbes, such as Bifidobacterium and lactic acid bacteria, feast on chocolate. When you eat dark chocolate, they grow and ferment it, producing compounds that are anti-inflammatory."
When these compounds are absorbed by the body, they lessen the inflammation of cardiovascular tissue, reducing the long-term risk of stroke. The other bacteria in the gut are associated with inflammation and can cause gas, bloating, diarrhea, and constipation. These include some Clostridia and some E. coli.
The team tested three cocoa powders using a model digestive tract, comprised of a series of modified test tubes, to simulate normal digestion. They then subjected the non-digestible materials to anaerobic fermentation using human fecal bacteria.
Cocoa powder, an ingredient in chocolate, contains several polyphenolic compounds such as catechin and epicatechin, and a small amount of dietary fiber. Both components are poorly digested and absorbed, but when they reach the colon, the desirable microbes take over. "In our study we found that the fiber is fermented and the large polyphenolic polymers are metabolized to smaller molecules, which are more easily absorbed. These smaller polymers exhibit anti-inflammatory activity," said John Finley, who led the research.