Chocolate compounds improve memory in new study
High doses of flavanols from cocoa increased the blood supply to a part of the brain called the dentate gyrus – a part of the "memory centre" of the brain known as the hippocampus – the researchers say in the study published in Nature Neuroscience.
"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," Scott A. Small, one of the paper’s authors, told reporters.
The news is promising, but should be taken with a little caution due to the small size of the study, which was performed on just 37 participants aged between 50 and 69.
Nevertheless, the work by researchers at Columbia University Medical Centre in the United States has been greeted with interest.
Previous studies have identified declining activity in the dentate gyrus as being linked to memory loss. But the Columbia scientists said it was the first direct evidence that this form of memory decline can be improved by a dietary intervention.
Dr Ashok Jansari, a cognitive neuropsychologist in the Department of Psychology at Goldsmiths College (University of London), said he was excited by the study.
"By refining very complex neuroimaging techniques that allow changes in biological activity to be measured, the authors were able to examine how functioning of the gyrus is affected by certain chemicals found in cocoa called flavanols," he said.
He acknowledged the limitations of the study due to its small sample size.
"However, given the complexity of the design of the study and its longitudinal nature requiring follow-up over three months, the findings simply suggest that larger scale and longer-term follow-ups are required," he said.
Dr Clare Walton, Research Manager at the Alzheimer's Society in the UK, said the study was well-designed "but as yet we don't know whether these brain changes are involved in dementia".
"With the winter nights setting in, many of us will be settling down with a nice hot cup of cocoa at the end of our day. However, the jury is still out as to whether partaking in things high in antioxidants can improve your memory or reduce your risk of dementia."
Chocolate – or at least the flavanols in cocoa – have been identified as having a range of health benefits such as reducing cardiovascular disease and stroke. We took a look at these claims last year and found some of the results promising, although some scientists are suspicious about chocolate industry funding for some of the research.