How a cup of good cocoa can benefit your brain

In my talks I often recommend that caregivers treat themselves to a ‘hot chocolate moment’. I’m inspired by the old commercial of a mother settling the babysitter with the baby then disappearing into the kitchen to make herself a cup of hot chocolate. Then she sits, eyes closed, delighting in the moment and de-stressing. All caregivers need to have ‘hot chocolate moments.’ Now recent research reveals that if the hot chocolate contains a good amount of cocoa it may do even more good, by benefiting blood vessels in the brain.

Previous studies had shown that eating foods rich in flavanols benefits vascular function throughout the body, and the research aim as to see this also applied to brain vascular function and cognitive performance.

So, scientists at the University of Illinois and the University of Birmingham (Illinois) tested a small number of healthy people to check if brain function improved after consuming cocoa. Project leader Professor Catalina Rendeiro, a lecturer in nutritional sciences said, ‘flavanols are small molecules found in many fruits and vegetables, and cocoa, too. They give fruits and vegetables their bright colours, and they are known to benefit vascular function. We wanted to know whether flavanols also benefit the brain vasculature, and whether that could have a positive impact on cognitive function.’

The team recruited adult non-smokers with no known brain, heart, vascular or respiratory disease reasoning that any effects seen in this population would provide robust evidence that dietary flavanols can improve brain function in healthy people. They tested participants before their intake of cocoa flavanols in two separate trials. In one, participants received flavanol-rich cocoa and in another they consumed processed cocoa with very low levels of flavanols. Neither participants nor researchers knew which type of cocoa was consumed in each of the trials – giving a double-blind study preventing researchers’ or participants’ expectations from affecting the results.

About two hours after consuming the cocoa, participants did the standard test of seeing how brain vasculature performs, by breathing air with 5% carbon dioxide – about hundred times the normal concentration which usually means the body reacting by increasing blood flow to the brain. This brings in more oxygen and allows the brain to eliminate more carbon dioxide. Then how well the brain defends itself from the excess carbon dioxide can be measured. Participants were also challenged with complex tasks that required them to manage sometimes contradictory or competing demands. Most participants had a stronger and faster brain oxygenation response after the cocoa flavanols than they did before drinking the cocoa or after drinking cocoa without flavanols.

Participants also did better on the most challenging cognitive tests, solving problems 11% faster than they did before or with cocoa with reduced flavanols. There was no measurable difference in performance on the easier tasks, however, suggesting that flavanols might only be beneficial for cognitive tasks that are more challenging.

A small number of people showed no meaningful differences in brain oxygenation response after drinking the cocoa with flavanols and neither did their cognitive performance improve. Professor Rendeiro said that this group may indicate that those who are already quite fit have little room for improvement, but overall the findings suggest that after exposure to flavanol’s there are improvements in vascular activity and in cognitive function.’

It looks that a cup of flavanol rich cocoa at bedtime is a very good idea!