Why physical activity improves brain health

Question: I am 68 years old and have been suffering from depression and memory problems for some time. The psychiatrist and neurologist, in addition to taking the medications, insist that I have to do physical activity. Does it seem so important to you? (Camilo Remillo, from Rosario)

One of the main reasons why People often feel good after going for a walk, run, or bike ride It is because the body releases dopamine and serotonin, neurotransmitters closely linked to the feeling of well-being.

Multiple studies have also shown that people who do physical activity several times a week They have on average higher performances and scores on cognitive tests, compared to those who lead a sedentary life. At the same time, it significantly reduces anxiety and depression.

However, for the benefits on brain structure to really begin to be consolidated, it is necessary that The exercise is done constantly and not sporadically.

It all starts with increased muscle activity. Molecules are released – where irisin should be highlighted – that travel through the blood until they reach the brain and fatty tissue, especially.

On the latter, irisin transforms white fat into brown fat, which increases total energy expenditure and helps maintain or even lose weight body since it increases sensitivity to the action of insulin, releases more free T4 (hormone produced by the thyroid) and seems to have a certain antitumor effect in some types of cancer.

In short, irisin would have a protective action against different diseases, especially metabolic ones.

It has neuroprotective qualities on the brain and a link between regular physical activity and benefits on cognitive health has been demonstrated, according to statements by C. Wrann, professor of medicine at Massachusetts General Hospital and Harvard Medical School.

Better blood circulation due to physical activity is essential for stimulate the growth of new blood vessels in the brain. It’s not just that there is an increase in blood flow, but the various molecules that come from the muscle reach the brain and allow other chemicals to be released locally.

In this case, the main one is a hormone called Brain-Derived Neurotrophic Factor, key to the health of neurons and the creation of new connections between them. Some authors compare it to a fertilizer for neurons because they heal and/or help those who are damaged recover.

These molecules, together with the better cerebral circulation, allow or facilitate the increase in the size of some areas of the brain, which is more noticeable in older adults since can compensate for the loss of brain volume which normally occurs over time.

An important area is the hippocampus, key to maintaining a good memory and a better mood, especially if it is already affected. The brain shrinks with age, which could be prevented by doing regular physical activityresulting in a protective factor against Alzheimer’s.

And something similar happens with depression, since in depressed patients the hippocampus is smaller than in healthy people.

In March 2023 the magazine Science published research with the title “Combating brain shrinkage. “Aerobic exercise can prevent the decrease in brain density.”