The study, by the National Institute on Aging and the National Heart, Lung, and Blood Institute, involved 60 people with an average age of 73 who did not have dementia. Participants drank two cups of hot cocoa per day for 30 days and did not eat any other chocolate. They were given memory and thinking skills tests, as well as ultrasound tests to measure the amount of blood flow to the brain.

Of the 60 participants, 18 had impaired blood flow at the start of the study. The results of the study showed that for those 18 participants, there were improvements in blood flow to the brain and in tests of their working memory. There were no such improvements for participants with regular blood flow.

MRI scans were also performed on 24 participants, to look for tiny areas of brain damage. The scans showed that people with impaired blood flow were more likely to have these areas of brain damage.

Alzheimer’s Society comment:

‘We know that poor blood flow can affect people’s brain power because they don’t have enough fuel in their brain cells to complete tasks efficiently. From this small but interesting study, it seems that cocoa helps improve blood supply to the brain, therefore having a knock on effect of improving people’s cognition.

‘Although this could be good news for those who enjoy a relaxing hot chocolate before bed, we do need further research to better our understanding of the link between cocoa and cognition, and also whether it has any impact on dementia. There are 800,000 people with dementia in the UK, and this is a growing number, so we need to do everything we can to identify ways of improving brain health andreduce the risk of people developing the condition.’

Dr Doug Brown
Director of Research and Development
Alzheimer’s Society , study published ( 7 August 2013) in Neurology®.