As the weather gets colder, it is timely that this week’s blog focuses on a favourite hot milky drink, the cup of cocoa.
In a small study published at the end of October, scientists reported that flavanols, compounds naturally found within the cocoa bean, enhanced the cognitive abilities of older people.
In the study, 37 participants aged 50 to 69 were given high (900 mg/d) or low doses (10 mg/d) of cocoa flavanols over 3 months. In a pattern recognition memory test, those who had consumed a high dose performed faster, although not more accurately, than those who received a low dose. Using complex imaging techniques the researchers found increased function in an area of the brain’s hippocampus called the dentate gyrus, which has been linked to this type of memory. As for why flavanols would help, it may be that they improve brain blood flow, or that they cause dendrites, message-receiving branches of neurons, to grow.
Can cocoa flavanols delay or prevent dementia?
The prospect of being able to halt or reverse age-related memory decline or dementia through a simple dietary intervention is, of course, appealing, but before we race down the supermarket to pick up the largest tub of cocoa (or all the chocolate bars) we can find, what does this study really show?
It is important to remember that the study didn’t look at dementia and we cannot tell from this research whether a diet high in cocoa would have any effect in delaying or preventing the condition.
There was no increased activity in another hippocampal region, the entorhinal cortex, which is impaired early in Alzheimer’s disease. That reinforces the idea that age-related memory decline is different and suggests that flavanols might not help Alzheimer’s, even though they might delay normal memory loss. There is also no indication as to whether the improvements measured would be significant to people in their daily lives. Unfortunately the study is very small so doesn’t allow meaningful conclusions.
Furthermore it is estimated that to consume the high-flavanol group’s daily dose you may need about 100 grams of high flavanol unsweetened cocoa powder, although concentrations vary widely depending on the processing, and the study used a specially prepared formula.
Can a cup of cocoa help us find our keys?
Whilst cocoa can make a comforting hot milky drink on a cold night, we are far from knowing whether the compounds in cocoa will have any impact on how well we remember names or where we’ve parked the car or put the keys. Much larger studies will need to be done.
