Increased consumption of flavanols – a set of molecules that occur naturally in vegetables and fruit – may raise your mental agility, according to new study at the University of Birmingham.
A team in the University’s School of Sport, Exercise and Rehabilitation Sciences found that people given a cocoa drink containing elevated levels of flavanols could complete certain cognitive tasks more efficiently than when ingesting a non-flavanol enriched-drink.
The study participants also underwent noninvasive brain imaging to measure blood oxygenation levels in your mind. Working with specialists at the University of Illinois, the researchers revealed that participants who had consumed the flavanol rich drink produced a quicker and larger increase in blood oxygenation levels in reaction to unnaturally elevated levels of CO2 (hypercapnia).
Flavanols, a sub-group of plant flavonoids, are present in cocoa, vegetables, fruits, apples, tea, berries and other foods. They are proven to have a beneficial effect on cardiovascular health, but their consequences on brain health are not well known.
Lead author, Dr Catarina Rendeiro, of the University of Birmingham’s School of Sport, Exercise and Rehabilitation Sciences, of the University of Birmingham’s explains: “We used cocoa in our experiment, but flavanols are extremely common in a wide range of fruit and vegetables. By better understanding the cognitive benefits of eating these food groups, as well as the wider cardiovascular benefits, we can offer improved guidance to people about how to make the most of their dietary choices.”
In the study, 18 healthy male participants aged between 18 and 40 underwent a typical procedure to challenge the brain’s blood circulation that involves breathing 5 percent carbon dioxide – roughly 100 times the normal concentration in air, producing an effect called hypercapnia. Non-invasive near-infrared spectroscopy, a method which uses light to capture changes in blood oxygenation levels, was utilized to monitor the growth in brain oxygenation from the frontal cortex in response to this carbon dioxide challenge.
Each participant failed the evaluation before and after drinking a cocoa beverage on two occasions and on one of these occasions, the drink has been enhanced with flavanols. Following the carbon dioxide test, the participants were requested to complete a number of progressively complex cognitive tests.
The researchers discovered that the participants who had taken the flavanol enriched drink had the highest degrees of blood oxygenation in response to hypercapnia, reaching levels up to three times greater than participants drinking the non-flavanol-enriched drink.
From the cognitive evaluations, the researchers found significant differences in the speed and precision with which volunteers completed the higher sophistication tasks, with volunteers who’d taken the flavanol enriched beverage performing the jobs 11 per cent faster on average.
“Our results showed a clear benefit for the participants taking the flavanol enriched drink – but only when the task became sufficiently complicated,” explains Dr Rendeiro. “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. It also further suggests that flavanols might be particularly beneficial during cognitively demanding tasks”.
The investigators also noted a further outcome. Within the analysis cohort, there was a small group who did not benefit at all in the flavanol enriched beverage in terms of blood oxygenation levels, and who did not derive any cognitive benefit. This group was shown to have existing high levels of brain oxygenation reactions to start with that weren’t increased further by drinking the improved cocoa. “This may indicate that some individuals, that perhaps are already very fit, have little room for further improvement” explain Dr. Rendeiro.
“The small group of participants who did not react to the flavanol gives us additional evidence to confirm the link between increased brain blood oxygenation and cognitive ability,” adds Dr Rendeiro.
Related Journal Article: https://www.nature.com/articles/s41598-020-76160-9