Dr Ashok Jansari, cognitive neuropsychologist at Goldsmiths College, said: "Given a globally ageing population, by isolating a particular area of the brain that is weakening in functioning as we grow older, and demonstrating that a non-pharmacological intervention can improve learning of new information, the authors have made a significant contribution to helping us improve our cognitive health."
The study, published in the online periodical Nature Neuroscience, follows research indicating cardiovascular benefits from cocoa. However, experts said the study did not mean people should eat more chocolate, as the product used in the experiment was a specially made drink formulated from cocoa beans.
The research did not look at the impact of cocoa on dementia, which is different to age-related memory decline.
Dr Simon Ridley, of Alzheimer's Research UK, said: "This very small trial highlights some possible effects of flavanols found in cocoa beans over a short time period, but we'd need to see much longer, large-scale studies to fully understand whether a diet high in these flavanols could boost cognition in old age."
Dr Liz Coulthard, a senior lecturer in dementia neurology at the University of Bristol, said: "Only reaction times, and not accuracy of performance, were actually improved and being faster without being more accurate is not always an advantage."
- Independent