Science Behind Dark Chocolates Heart-Health Benefits

DALLAS—Scientists have identified how certain bacteria in the gut are responsible for dark chocolate’s role in reducing inflammatory and boosting heart health, according to research presented at the 247th National Meeting & Exposition of the American Chemical Society (ACS).

Researchers found good microbes, such as Bifidobacterium and lactic acid bacteria, feast on chocolate when it is consumed, grow and ferment it, producing compounds that are anti-inflammatory. However, other bad bacteria in the gut, such as Clostridia and E. coli, are associated with inflammation and can cause gas, bloating, diarrhea and constipation.

“When these compounds are absorbed by the body, they lessen the inflammation of cardiovascular tissue, reducing the long-term risk of stroke," said lead researcher John Finley, Ph.D., Louisiana State University. Finley said this is the first study examine the effects of dark chocolate on the various types of bacteria in the stomach.

For the study, researchers at Louisiana State University 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 contains several polyphenols, including 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," he said.

Finley also said that combining the fiber in cocoa with prebiotics is likely to improve a person’s overall health and help convert polyphenolics in the stomach into anti-inflammatory compounds.

“When you ingest prebiotics, the beneficial gut microbial population increases and outcompetes any undesirable microbes in the gut, like those that cause stomach problems," he said.

He suggested people could experience even more health benefits when dark chocolate is combined with solid fruits like pomegranates and acai.