Over the years the body's defenses tend to weaken, the level of inflammation increases and the consequence is a higher predisposition to infections, bacterial and viral, that are also characterized by a higher severity. But there is a way to slow down or even postpone this decline, and that is physical exercise. Choosing an active life, at all ages, therefore, rejuvenates the body but also the cells of the immune system, as emerges from a recent review published in the journal Immuno by a German team (Brauer et al, Immuno, 2021).
The immune system ages, too
Like all other organs and tissues in the body, also the immune system ages. As a consequence, its ability to react to attack by pathogens, whether they are viruses, bacteria, fungi or toxins, decreases. Lifestyle helps to counteract the aging processes. In particular, the article we are talking about today focused on the analysis of the effects on the immune system of physical activity that, as we will see, can slow down the aging of the immune system, when practiced in old age, or even delay it, if the active life is chosen from an early age. In short, physical activity would be a true elixir of youth, capable of turning back the hands of the biological clock. But let's try to understand better.
Physical activity rejuvenates the immune system, the research
In order to understand the link between physical activity and the health of the immune system, scientists analyzed the results of previous research that investigated the connection between health and lifestyle of volunteers, in all about 440 people. What emerged is that exercise increases, in those who practice it, the number of T helper lymphocytes, which are the cells of the immune system that play a key role in guiding the body's response to external attacks, and of cytotoxic T lymphocytes, designed to destroy cells infected by viruses and cells with degeneration. Already only after a treadmill session, for example, CD8 + cells were increased, which counteract the action of viruses, bacteria but also the processes that lead to the development of tumors. Also noteworthy is the observation that, in those who perform moderate physical activity, the telomeres are longer. Telomeres are the terminal part of each chromosome with the purpose of protecting it from deterioration. Over time, telomeres shorten until they are no longer able to protect chromosomes and the cell ages, unable to carry out its tasks. Longer telomeres therefore mean a longer life for the cell, which in fact is as if it could rejuvenate itself every time physical activity is performed, but always without excess. Instead, exercise has been shown to reduce senescent T cells, which are still cells of the immune system but which have undergone aging and are highly pro-inflammatory, stimulating the inflammation and the weakening of the defenses themselves.
More benefits with resistance exercise
In addition, among all types of physical exercise, resistance training has shown the greatest benefits compared to training that aims only to strengthen the muscles, such as weight lifting. By endurance training we mean all those exercises, from swimming, brisk walking or bicycle, which improve physical endurance, that is the ability to undergo effort for a prolonged period of time.