“Min Sana in Corpor Sanu”, the perfect mind in healthy body. This quote is often used to highlight the beneficial effect of physical activity on mental abilities. In fact, the phrase, which appears in “Satire X” written approximately in the second century by the Latin poet Juvenal, goes even further: it indicates that one must pray in order to have a sound mind in a sound body (“Orandum est ut sit mens sana in corpore sano”).
Aside from this literary approximation, what can be said physiologically about the benefits of maintaining a healthy, balanced body and exercising our mind? Can exercise really help preserve our mental and brain abilities? Yeah. There is a lot of scientific data to support this, especially regarding the consequences of aging.
The brain becomes thinner with age
As we age, our tissues and organs deteriorate. The ability of cells to reproduce and repair themselves and thus remain functional is reduced, and this is accompanied by a gradual loss of tissue. For example, it is difficult to maintain well-developed muscles … This phenomenon also occurs in the brain, which leads to neurodegeneration, or the loss of neurons.
Concretely, both during diseases (eg Alzheimer’s disease) and during normal aging, various changes occur:
thinning of the cortical region (superficial regions);
loss of gray matter (neuronal cell body) and white matter (neuronal pathways, axons of neurons);
increased size of the ventricles (a group of cavities within the brain where cerebrospinal fluid circulates);
And a decrease in the number of neurons in different areas, especially in the hippocampus (important for memory, orientation in space, etc.).
It was established in the Baltimore study, which included hundreds of volunteers and continued over several years, that the decrease in metabolic capacity associated with aging must be associated with an increase in the size of the cerebral ventricle, this “hollow” space of the brain. Which leads to increased neurodegeneration and atrophy of our thinking system.
If a decrease in our ability to metabolize results in a loss of brain volume, we can conclude that better use of energy through physical exercise can slow down the loss of brain tissue…really?
More exercise, more memory
It is not easy to get the answer. Especially because it is difficult for us to quickly measure the effect and results of any intervention of any kind on the brain. The brain is not like blood or muscles, which quickly show a response that can be easily measured directly or from blood components.
The good news is that the advent of increasingly reliable imaging methods can detect part of the structural changes in certain areas of the brain.
Thus, physical exercise has been shown to improve cognitive abilities and increase the size of certain areas of the brain, particularly those related to memory. For example, in 2011, an article was published in the Proceedings of the National Academy of Sciences She indicated that physical exercise increases the size of the hippocampus. Other studies in older adults have shown that physical exercise also prevents volume loss in this brain region.
On the other hand, a positive relationship has been demonstrated between physical exercise and the amount of gray matter in other brain regions sensitive to age-related degeneration (such as the temporal lobe).
We tend to think of our bodies as a fragmented system. If we have a liver problem, we focus on the liver, and if it is a kidney problem, we focus on the kidneys. But our body does not work that way: everything is interconnected. This is why a kidney problem can aggravate heart disease, and a liver problem can lead to cerebral ischemia. However, during old age, in particular, complex body balances are in a very critical situation.
When we exercise, we put our bodies under moderate stress because we force our cells to increase their energy expenditure. This involves mobilizing the nutrients that need to be moved from the stores to the muscles. All the physiological changes needed to deal with this moderate stress are known as “hormones.”
During this process, the muscles release substances that inform the rest of the organs that the demand for energy is increasing. These contact substances are called “myokins” and are released into the blood for distribution to other organs.
Some of these myokins reach the brain, where they stimulate the expression of genes (and thus protein synthesis) which increases the ability of neurons to make new connections or strengthen existing ones. One of these myokins is brain-derived neurotrophic factor (BDNF), which is required for neurons to make connections and thus remain active. This is why physical exercise maintains brain volume – in our daily lives, but also during old age.
On the other hand, physical exercise increases the flow of blood and oxygen, which positively affects brain activity, including in the elderly.
Finally, other studies have shown that moderate physical exercise produces anti-inflammatory effects that can affect the brain, thus reducing, for example, the development of Alzheimer’s disease or dementia.
Scientific evidence, direct and indirect, clearly shows that as we age, physical activity helps prevent brain degeneration … thus giving the full meaning of the term “mens sana in corpore sano”. So it is better to avoid inactivity and sedentary lifestyles if we want to add life to years and not just years.
This article has been republished from The Conversation under a Creative Commons license. Read the original article.