Dark Chocolate Secrets Slowly Unravel

chocolateDark chocolate lovers now have more reason to unravel their favorite treat more often. Scientists have uncovered some of dark chocolate’s secrets to explain why they it can be healthy and why consumers should not feel guilty about eating an extra piece of chocolate.

At the 247th National Meeting & Exposition of the American Chemical Society (ACS) in Dallas, Texas, researchers revealed that certain bacteria in the stomach munch on chocolate and ferment it into an anti-inflammatory substance that benefits the heart and the digestive system.

Maria Moore, one of the researchers and an undergraduate student at Louisiana State University’s College of Agriculture, said that the good microbes, such as Bifidobacterium, consume the chocolate in which they grow and ferment; the process produces compounds that are anti-inflammatory.” The “bad” bacteria, such as E. coli and Clostridia, cause inflammation, gas and diarrhea.

Dr. John Finley, Ph.D., who led the team research, said these compounds decrease inflammation in cardiovascular tissues, which reduces the risk of getting a stroke.

Scientists have already unraveled some of the secrets to why dark chocolate can contribute to better health. Chocolate and bacteria go hand in hand when it comes to how good bacteria are delivered. In 2010, Dutch researchers from Ghent University showed that good bacteria — Bifidobacterium and Lactobacillus — are protected from the stomach acid by the chocolate’s coating. This process allows the bacteria to reach the small and large intestines and the colon, with a survival rate of 91 percent in dark chocolate and 80 percent in milk chocolate.


Another benefit of consuming dark chocolate is that it can help curb appetite. In 2011, scientists at the University of Denmark found that dark chocolate reduces caloric consumption by 8 percent more than milk chocolate consumption among young, healthy women. This calculation factors in calories that are already in the chocolate.

By using a model to mimic the human digestive system, Finley’s research team is able to use a contraption of modified test tubes to simulate digestion. Indigestible compounds are then fermented with bacteria from human feces, explains Finley. Mimicking the human lower intestines is no easy and clean task. In fact, graduate students are paid $20 to give the researchers a sample of their stools, said Finley. As gross as it may sound, these stools are teeming with bacteria that just want to swan dive into the cocoa powder mixture.

Cocoa powder, a raw ingredient in dark chocolate, is packed with an antioxidant compound called polyphenols, which include catechin and epicatechin, and traces of dietary fiber. These polyphenols are also found in black tea and dark-colored berries. However, these compounds are too large to be absorbed into the blood via the digestive tract. These microbes ferment the fiber and break the large polyphenols down to the level that the body can absorb them. These smaller compounds contain anti-inflammatory properties.

The study, however, does not explain how these antioxidants benefits the heart.

Joshua Lambert, Ph.D., an associate professor of food science at Penn State in Pennsylvania, states that issue is the missing link to determine if there is a direct correlation between dark chocolate consumption and a healthier heart.  “We know now that gut bacteria can break down cocoa into compounds that have beneficial cardiovascular effects. But we don’t know yet if these are the critical ones inside the blood.”

The research on dark chocolate is just the beginning. Scientists have yet to unravel a few of dark chocolate’s little secrets. Finley said that the next step in the research is to check and measure the amount of polyphenols in the blood of subjects after they have consumed cocoa powder. Meanwhile, chocolate lovers can enjoy an extra piece of dark chocolate, knowing that it will more likely increase their immune system’s function, not their waistline.

By Nick Ng



International Journal of Food Microbiology

Nutrition & Diabetes

American Chemical Society