Cocoa can help to slow and even reverse age-related memory loss, according to a study pointing to the previously unknown mental benefits of the chocolate ingredient.
Scientists believe that flavanols, the antioxidants inside cocoa beans, can give people in their sixties the memory of a "typical 30- or 40-year-old".
The study, by the Columbia University Medical Centre in New York, is thought to be the first evidence that age-related memory decline - a common problem that can cause older people to forget small things like the names of acquaintances or where they have placed their keys - can be countered through dietary changes.
The trials involved 37 volunteers, aged between 50 and 69, divided into two groups. One group was administered daily drinks with a high (900mg) dosage of flavanols, while the other was offered just 10mg a day. After three months, the group that drank the high intake showed signs of faster and clearer recognition of visual patterns. Brain scans before and after the trial showed more blood within the dentate gyrus part of the hippocampus, one of the few regions known to generate fresh brain cells.
"If a participant had the memory of a typical 60-year-old at the beginning of the study, after three months that person on average had the memory of a typical 30- or 40-year-old," said the senior author, Dr Scott A Small.