- Consuming flavanol-rich food can improve vascular function.
- Flavanols are commonly found in berries, tea, grapes, and cocoa.
- Researchers have now found evidence of cocoa flavanols boosting one’s brain function and cognitive performance.
A cup of hot cocoa can help keep you warm on a cold, gloomy night. But it seems that’s not all it’s good for. A study published in the journal Scientific Reports has found evidence of cocoa flavanols improving cognitive functioning in young healthy adults.
Researchers from the University of Birmingham and the University of Illinois at Urbana-Champaign conducted a small-sample study to investigate the effects of flavanols on the brain. They recruited 18 male volunteers aged between 18 to 45 years. The volunteers were all non-smokers with no history of co-morbids.
Flavanols are small molecules found in many fruits and vegetables, and cocoa, too. They give fruits and vegetables their bright colors, 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.
Dr. Catarina Rendeiro, lead author
Cocoa Flavanols Boost Brain Performance
The 18 participants underwent two separate trials. One involved consumption of flavanol-rich cocoa and the other involved drinking cocoa with low levels of flavanols. Since this was a double-blind study, nor the researchers or the participants knew the type of cocoa consumed in each trial.
In each trial, participants underwent testing before and after consumption of their cocoa drink. Participants breathed air containing 5% carbon dioxide. This is a standard method of challenging an individual’s cerebrovascular circulation. This produces a state of hypercapnia and causes the body to increase blood flow to the brain. Additionally, participants underwent brain scans to measure blood oxygenation levels in the brain. Participants also completed complex cognitive tasks.
Results showed 14 out of the 18 participants had significant improvement in their cognition and brain oxygenation after consuming the flavanol-rich cocoa.
Volunteers Solve Problems 11% Faster
The researchers noticed that the more complex the task, the better the performance in the flavanol-rich cocoa group. Thus, proposing flavanol’s role in challenging cognitive tasks. Moreover, in the flavanol-rich trial, participants had the highest level of blood oxygenation and achieved these levels faster than those who drank non-enriched cocoa.
Our results showed a clear benefit for the participants taking the flavanol-enriched drink – but only when the task became sufficiently complicated. We can link this with our results on improved blood oxygenation – if you’re being challenged more, your brain needs improved blood oxygen levels to manage that challenge.
Dr. Catarina Rendeiro, lead author
Participants who consumed cocoa flavanols also completed complex cognitive tasks 11% faster than those who did not. Thus, further confirming flavanols cognitive benefits.
However, the researchers noticed that a small group of participants, 4 out of 18, showed no significant differences in cognition or brain oxygenation. That is, even after consuming cocoa flavanols. These participants demonstrated high levels of brain oxygenation at the start of the study. Therefore, researchers believe that only individuals with low cerebrovascular circulation benefit from the effects of flavanols.
Despite the positive results, the study has a few limitations such as small sample size, and exclusion of females. Further studies should therefore focus on these factors.
However, the overall findings of the study add to the evidence of flavanols’ cognitive benefits.
Reference:
‘Dietary flavanols improve cerebral cortical oxygenation and cognition in healthy adults,’ Scientific Reports (2020). DOI: 10.1038/s41598-020-76160-9
