The study, published this week in the journal Neurology, found that two cups of hot cocoa per day improved some participants' memory and thinking abilities while also increasing blood flow to the brain. 60 people with an average age of 73 participated in the study, and 18 of them had "impaired blood flow." By the end of the 30-day study, blood flow had improved 8.3% for those people.
"We're learning more about blood flow in the brain and its effect on thinking skills," said Dr. Farzaneh Sorond, a faculty member at Harvard Medical School and a member of the American Academy of Neurology. "As different areas of the brain need more energy to complete their tasks, they also need greater blood flow. This relationship, called neurovascular coupling, may play an important role in diseases such as Alzheimer's."
Study participants who had impaired blood flow were also found to do better on a working memory test, with average test times decreasing from 167 seconds to 116 seconds after the 30 days of cocoa. Those who did not already have impaired blood flow did not have their memories or blood flow affected by the cocoa. The study also found no difference between regular hot cocoa and hot cocoa containing the antioxidant flavanol.
"More work is needed to prove a link between cocoa, blood flow problems and cognitive decline," said Dr. Paul Rosenberg, the director of the memory and Alzheimer's treatment center at the Johns Hopkins School of Medicine. "But this is an important first step that could guide future studies."