Saturday , January 16 2021

The study shows that dietary flavanols increase oxygenation and cognition in the brain of healthy adults



Consumption of flavanols, naturally occurring compounds found in plants, is associated with cognitive and cerebrovascular benefits in adults, according to new research published in Scientific reports. The study provides evidence that flavanol intake results in faster and greater oxygenation in the brain in response to the accumulation of carbon dioxide in the bloodstream.

“For the past 10 to 12 years, I have been interested in the health benefits of herbal flavonoids, especially their effects on the brain and cognitive function,” said study author Catarina Rendeiro, a lecturer in nutrition at the School of Sports, Exercise and Rehabilitation at the University of Birmingham.

“We have for many years shown that cocoa flavanols (in particular) can improve vascular function in humans by improving vascular / arterial function. These benefits are obvious even after a single dose. However, the extent to which some of these benefits could be translated into cerebral vessels was less clear. ”

Given that we have more and more people suffering from cognitive impairment and neurodegenerative diseases later in life (and we mostly live longer), it is important that we make the lifestyle choices (exercise, diet) that can maximize the protection of the brain and help delay the onset of cognitive dysfunction as we age, ”explained Rendeiro.

For their study, which used a double-blind methodology, the researchers tested 18 healthy male participants in two separate studies, one in which the subjects received flavanol-rich cocoa and another in which they consumed processed cocoa with very low levels of flavanols. The flavanol-rich cocoa contained 150 mg of epicatechin and 35.5 mg of catechin, while low-flavanol cocoa contained less than 4 mg of both flavanols.

Participants underwent a standard procedure to challenge the brain’s blood circulation, which involves breathing 5% carbon dioxide – about 100 times the normal concentration in air, which produces an effect called hypercapnia. Non-invasive near-infrared spectroscopy, a technique that uses light to capture changes in blood oxygenation levels, was used to track the increase in brain oxygenation in the frontal cortex, a brain region that plays a key role in planning, regulating behavior and decision-making. .

Participants were then asked to complete a number of gradually complex cognitive tests.

The researchers found that participants who had taken the flavanol-enriched drink tended to have more effective tissue oxygen defense in the frontal cortex. The improved oxygenation in the brain also seemed to translate into improvements in cognitive performance on tasks with higher complexity (but not with lower complexity tasks.)

The results show that “consumption of foods rich in flavanols, such as grapes, green tea, apples, berries and unprocessed cocoa powder can provide levels of flavanols that are beneficial for oxygenation and cognitive function in the brain,” Rendeiro told PsyPost.

“The fact that flavanols can be effective even in a healthy brain (where physiology works exactly as it should) is a remarkable discovery and it means that we can potentially all benefit from diets rich in flavanols.”

But as with all research, the study includes some precautions.

Women were not included in the study to ensure a more homogeneous sample and to minimize the effects of hormonal fluctuations. “The effect of flavanols in women has not been addressed in this study, so it is possible that women respond differently. This is something that must be seen in the future, “Rendeiro explained.

“We also need to better understand the mechanisms underlying these beneficial effects. How do these compounds affect oxygenation levels? ”

“Effective oxygenation of the brain is the key to cognition and impairments in this process are common in people in old age or with a higher risk of cardiovascular disease or dementia. So in the future, it would be important to look at whether these positive effects that we see in young people can be translated into risk populations, as they are likely to benefit the most, ”Rendeiro added.

Although the study examined flavanols from natural cocoa powders, chocolate intake would probably not have the same effect.

“Many people tend to associate the benefits of cocoa with chocolate, but these are two very different things. The cocoa containing flavanols is normally unprocessed. But when you process cocoa beans to make chocolate (roasting, alkalization, etc.), the flavanol content decreases, ”Rendeiro explained.

“Unfortunately, it is difficult to know what the content of flavanols is in chocolate products because these are not removed in labels. In general, scientific articles that have measured the content of flavanols in commercially available chocolate do not seem to find any relationship between the content of cocoa solids and the levels of flavanols. ”

So having more cocoa solids does not necessarily correspond to more flavanol content. It is important that even chocolate that has the highest amounts of flavanols is still far from the effective doses. You need to consume a large portion of chocolate to reach the desired doses and it would not be advisable given the simultaneous intake of sugar and fat. Producing chocolate in a way that maintains the flavanol content should be a goal, so that we can get effective doses of flavanols from small amounts of chocolate (1 to 2 squares), says Rendeiro.

“The good news is consuming a variety of foods rich in flavanols, such as grapes, green tea, apples, berries, pulses can provide levels of flavanols that are beneficial to brain and vascular function.”

The study, “Diet Flavanols Improve Cerebral Cortical Oxygenation and Cognition in Healthy Adults,” was written by Gabriele Gratton, Samuel R. Weaver, Claire V. Burley, Kathy A. Low, Edward L. Maclin, Paul W. Johns, Quang S Pham, Samuel JE Lucas, Monica Fabiani and Catarina Rendeiro.




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