Dark chocolate's health benefits due to actions of gut bacteria
Gut bacteria get to work on dark chocolate producing anti-inflammatory compounds. (Rob Stark / shutterstock.com)
Published Thursday, March 20, 2014 1:37PM EDT
The idea that dark chocolate is good for your health is nothing new, however the exact reason why it's so darn beneficial has remained something of a mystery...until now.
Researchers have discovered a specific stomach bacteria that breaks down chocolate and ferments it into anti-inflammatory compounds, making the dark stuff highly useful in terms of heart health.
Findings were presented at the 247th National Meeting & Exposition of the American Chemical Society (ACS). The meeting is happening at the Dallas Convention Center and area hotels in Dallas, Texas through Thursday, March 20.
"We found that there are two kinds of microbes in the gut: the 'good' ones and the 'bad' ones," explained Louisiana State University undergraduate student and study researcher Maria Moore. "The good microbes, such as Bifidobacterium and lactic acid bacteria, feast on chocolate," she said. "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," said leader researcher John Finley, Ph.D. of Louisiana State. Finley also noted that the study is the first to examine the effects of dark chocolate on various types of stomach bacteria.
The professor and his team analyzed three cocoa powders using a model digestive tract designed to simulate normal digestion. The researchers then put non-digestible materials through anaerobic fermentation using human fecal bacteria. Cocoa powder is one of the main ingredients in chocolate, and contains several antioxidant compounds such as catechin and epicatechin, as well as a small amount of dietary fiber.
While both catechin and epicatechin are difficult for the body to digest and absorb, this changes when they reach the colon, as "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," Finley said.
Finley also remarked that combining cocoa's fiber content with prebiotics can contribute to overall health and help change antioxidants in the stomach into anti-inflammatory compounds. Prebiotics are food components found in raw garlic, whole wheat flour and other foods humans cannot digest but are heavily favored by gut bacteria.
"When you ingest prebiotics, the beneficial gut microbial population increases and outcompetes any undesirable microbes in the gut, like those that cause stomach problems," Finley said. He also noted that combining dark chocolate with solid fruits such as pomegranates is even more beneficial to health, and is likely the future of the industry.
Another recent study on dark chocolate and heart health found eating the stuff in moderation can reduce the risk of atherosclerosis, or the thickening and hardening of the arteries, by restoring arterial flexibility and preventing white blood cells from sticking to blood vessel walls. The study was conducted by a research team at the Top Institute Food and Nutrition and the Division of Human Nutrition at Wageningen University in the Netherlands and published in The FASEB Journal.