Is chocolate good for our health? Some components of dark chocolate may slow the aging process. Researchers at Kings College London isolated theobromine, a common compound in cocoa. Theobromine, the same chemical in chocolate that can be toxic to dogs, boosts blood markers of biological aging in humans. In the study, in the journal Aging, Senior author Jordana Bell put it more simply—that people with higher levels of theobromine in their blood had a biological age that was younger than their actual age. Other chemicals in cocoa and coffee did not show similar benefits. The authors are not saying that we should eat more dark chocolate. Rather, their work can help understand how everyday foods may hold clues to healthier, longer lives.