The precise reasons for these health benefits are many, but a new study presented at a recent meeting of the American Chemical Society explains much of it. On Tuesday, researchers at meeting of the American Chemical Society (ACS) in Dallas said they had solved the confection conundrum: Specific chocolate-loving microbes in the gut convert an otherwise indigestible portion of the candy into anti-inflammatory compounds, they said. The molecules are too large to cross the walls of the gut and be used as nutrients, according to researcher John Finley, a professor of food science and biochemistry at Louisiana State University. That is until they encounter some of the many microbes that inhabit the human colon, particularly Bifidobacterium and lactic acid bacteria, researchers said. A number of short-term studies conducted in recent years have suggested that dark chocolate can cause blood vessels to dilate, and thus lower blood pressure, although this is not the case with white chocolate and milk chocolate. In terms of the exact chemistry involved, cocoa powder contains several polyphenolic, or antioxidant, compounds such as catechin and epicatechin, and a small amount of dietary fiber.
– You've probably heard about the highly convenient health benefits of dark chocolate. As io9 points out, the stuff is good for your heart, your brain, and even your teeth. But just why is it so healthy? Researchers are explaining that the healthy bacteria in our digestive systems love dark chocolate. When they munch on it, the process releases compounds that reduce cardiovascular inflammation. That cuts our heart disease and stroke risk, io9 reports. The experts reached their conclusions by studying how cocoa powder interacts with digestive enzymes and bacteria contained in our feces, the Los Angeles Times reports. They learned that certain molecules from the chocolate can't be absorbed by our bodies on their own. Fortunately, once those molecules get to our colons, the bacteria take action. "These little guys say, 'Hey—there's something in there that I can use,' and they start to break it down," says Louisiana State researcher John Finley. About two tablespoons a day of cocoa powder appears to offer a health boost, he says. Unfortunately, the sugar and fat in chocolate candy aren't so good for us—so Finley opts to put cocoa powder on his oatmeal. (But soon, we may be able to just take "chocolate pills" to get the benefits.)