[Mise à jour du 17/07/21]
Study shows that spending time outdoors has a very positive effect on the brain
During the COVID-19 pandemic, pnature walks have become a popular and regular pastime. A hobby that researchers at the Max Planck Institute encourage to pursue as its benefits are numerous from a physical but also psychological point of view. In their study published in July 2021 in the review The World Journal of Biological Psychiatry, they set out to study the association between spending time outdoors and the structural plasticity of the brain. Their results show that this habit has a good effect not only on our general well-being through sun exposure, free time and physical activity, but alsoi on our brain structure.
As the scientific team explains, “This shows that the human brain benefits even from short stays outdoors. Until now, it was assumed that environments only affect us over longer periods of time. The researchers regularly examined six healthy middle-aged people for six months by performing a total of 280 magnetic resonance imaging scans of their brains. Another part of the study looked at their self-reported behaviors, particularly on the hours when participants spent outside, their fluid intake, their consumption of caffeinated beverages and their frequency of physical activity.
A beneficial effect on the gray matter of the brain
The results showed that the time spent outdoors by the participants was positively related to gray matter in a specific part of the cerebral cortex. However, this brain area is involved in the planning and regulation of actions as well as in what is called cognitive control. “In addition, many psychiatric disorders are known to be associated with a reduction in gray matter in the prefrontal area of the brain. “, Add the researchers. The researchers performed statistical calculations to examine the influence of sunshine duration, the number of hours of free time, physical activity and fluid intake on the results.
It turns out that the time spent outdoors had a positive effect on the brain, whatever the other influencing factors. “Our results show that our brain structure and mood improve when we spend time outdoors. It most likely affects concentration, working memory and the psyche as a whole as well. », Underlines Simone Kühn who took part in the study. “This finding confirms the supposed positive effects of walking on health and extends them through concrete positive effects on the brain. »An important finding in the field of psychiatry, given that most psychiatric disorders are associated with deficits of the prefrontal cortex.
On the basis of these results, the researchers decide in favor of the prescription outdoor walks because they could be a useful way to counter these neural alterations and improve mood. “This discovery provides neuroscientific support for the treatment of mental disorders. Doctors might order a walk in the fresh air as part of the therapy, similar to what is usual for health cures. », They note. In its next work, the scientific team wishes to compare the effects of green spaces to those of urban spaces on the brain, knowing that they are more exposed to negative factors such as noise and pollution.
To stimulate memory, you first need a healthy brain. It is impossible to make our neurons function without providing them with the necessary fuel. This requires a healthy lifestyle.
Food that stimulates neurons
It is recommended eat fish at least twice a week, preferably salmon, sardines and mackerel. These fatty fish are rich in Omega 3 long chain, including EPA and DHA.
“A high level of EPA in the blood plasma is associated with a lower risk of Alzheimer’s disease and depression. The EPA would have a anti-inflammatory effecte, while DHA is the main lipid component of neurons, ”explains Dr. Pascale Barberger-Gateau, epidemiologist at Inserm.
Fish, slow sugars, fruits and vegetables
Fish also contains selenium, an antioxidant, and vitamin D, which could also help keep our “gray cells” in shape. Their effect will be multiplied if we consume fish accompanied by fruits and vegetables naturally rich in antioxidant nutrients (vitamins C, carotenoids, polyphenols).
The glucose is the main fuel for the brain. It is better to favor slow sugars (cereals, wholemeal bread, etc.) which release a gradual dose into the blood.
Control your risk factors
Diabetes, cholesterol and high blood pressure are among the brain’s worst enemies. They have a deleterious impact on the blood vessels. However, a brain, in which the blood circulation is hurting, cannot give its full potential. All the more reason for eat green vegetables, rich in group B vitamins. These lower the level of homocysteine in the blood, an amino acid whose elevation is toxic to neurons and the cardiovascular system.
Emotions strengthen our memory. “They are a key factor in the reactivation of our memories, confirms Pascale Gisquet, neurobiologist at the CNRS. In the brain, emotions are processed by the amygdala, an area where the storage of information is strengthened.
When a memory is attachedat an emotional “label”, we remember it better. The effect is the same whether the emotion is sweet or bitter. Many people can vividly remember what they were doing when they learned of the World Trade Center collapse on September 11, 2001.
Live your emotions
But if emotions help us memorize, sometimes the mechanism gets carried away. Thus, the victims of post-traumatic stress (after a rape, an attack …) are haunted by violent images that loop in their heads. Likewise, sometimes an emotion that is too intense completely blocks memories, causing traumatic amnesia. “Actress Annie Duperey told in a book how the memory of the death of her parents, which she attended, came back to her in bits and pieces after years of amnesia,” adds Pascale Gisquet.
Treat your depression and anxiety
A chronic stress disrupts the functioning of the brain. Brain imaging shows that in depressed or anxious people, the hippocampus (brain area dedicated to memory) is atrophied. Likewise in depression, the prefrontal cortex (the area of planning and decision-making) slows down. Medication helps to get out of this state. All antidepressants increase the levels of chemical molecules (neurotransmitters) that facilitate dialogue between neurons. Gradually, cognitive faculties are reestablished. From anxiolytics, only benzodiazepines can interfere with memory, but only temporarily.
Maintain your physical and mental shape to boost your brain
During sleep, the brain consolidates the knowledge acquired during the day. Thus, the hippocampus could transfer the new information to other areas of the brain, so that it is stored for the long term. Logically, the lack of sleep disrupts this beautiful mechanism.
Have regular physical activity
Physical activity increases the production of growth factors that nourish neurons. At the same time, the density of blood vessels increases in the brain, which gives it a good oxygen supply. Thus, studies have shown that people who are physically active all their lives lose less brain tissue in old age and their cognitive performance is better. Ultimately, physical activity could delay the onset of Alzheimer’s disease. But that remains to be confirmed.
Make your brain work
The brain does its best when it comes to new problems and has to adapt. It is essential to never stop learning. Doing homework with your children is, for example, a good way to mobilize your brain, while reviewing your knowledge. But you can also take evening classes, learn a new language, travel …
For better memorization, favor paper over screens
A study published in March 2021 shows stronger brain activity after writing on regular paper rather than through a tablet or smartphone. This results in better memory. This is the observation made by a team of researchers from the University of Tokyo in a study published in March 2021 in Frontiers in Behavorial Neuroscience. Conducted with university students and recent graduates, it reveals that thewriting on paper can lead to greater brain activity when it comes to remembering information an hour later. And this thanks to the associated complex, spatial and tactile information hand writing on paper.
“In fact, paper is more sophisticated and useful than electronic documents because it contains more information unique to a better memory recall ”, Explains Prof. Kuniyoshi L. Sakai, who conducted the study. “Our take-home message is to” use notebooks for information we need to learn or memorize. »Clearly, the paper notebooks allow you to visualize spatial information more complex than digital “paper”, which is uniform, has no fixed position and disappears when the user closes their application.