A small clinical trial has shown that in older people, a diet supplemented with cocoa flavanols– naturally occurring compounds found in cocoa beans – may help blood flow in a brain region important for memory. The study is published on Sunday 26 October in the journal Nature Neuroscience online.
Researchers from Columbia University, New York University and MARS Inc recruited 37 healthy people aged 50-69 for the trial, which lasted for 12 weeks. At the start and end of the study, each participant was given an MRI scan to measure blood flow in the brain, and a series of cognitive tests to assess their thinking and memory. During the trial, the participants were divided into four groups that included either regular exercise and/or a diet high in a supplement containing cocoa flavanols:
- High-flavanol diet and regular exercise (one hour four times a week)
- High-flavanol diet and no exercise
- Low-flavanol diet and regular exercise
- Low-flavanol diet and no exercise
The researchers found that by the end of the study, those on a high-flavanol diet had increased blood flow in a region of the brain called the dentate gyrus, which is known to be important for memory formation. These groups also performed better on some cognitive tests at the end of the study, compared to those on the low-flavanol diet.
Dr Simon Ridley, Head of Research at Alzheimer’s Research UK, the UK’s leading dementia research charity, 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. We also don’t know how meaningful the improvements measured in the tests used here would be for people in their daily lives. This study didn’t look at dementia, and we can’t know from this research whether a diet high in cocoa would have any effect in either preventing or delaying the onset of the condition. The supplement used in this study was specially formulated from cocoa beans, so people shouldn’t take this as a sign to stock up on chocolate bars.
“Continued investment in research is crucial to find ways to protect the brain and prevent the diseases that cause dementia. Although there’s currently no certain way to prevent dementia, research shows that a healthy lifestyle can help reduce the risk of the condition. A healthy diet, regular exercise, not smoking, and keeping blood pressure and weight in check can all help lower the risk of dementia.”