New research into the function of natural killer cells in the body has found that endurance exercise boosts their efficiency and effectiveness in fighting disease and keeping us biologically young.
By indulging in prolonged physical activity such as long-distance swimming, cycling, running and rowing, older adults prime their natural killer (NK) cells to fight off the ravages of inflammation associated with illness and ageing.
NK cells are a type of white blood cell (lymphocyte) that can destroy infected and diseased cells, including cancer cells. They are at the forefront of the immune system because they detect and fight viruses and other pathogens.
It has been known for some time that endurance training provides better immune defence, resulting in stronger, long-lasting antibody responses to influenza vaccination, improved immunity and metabolic balance, and delayed ageing.
Now an international research team has found that exercise prepares the immune system by 'training' the cells to do their job better.
Luciele Minuzzi, a visiting researcher at Justus Liebig University Giessen in Germany, said: “In a previous study, we found that obesity and a sedentary lifestyle can trigger a process of premature ageing of defence cells.
"This made us want to investigate the other side of the story, that is, whether an older adult who has been practicing endurance exercises for more than 20 years may have a better-prepared immune system. And that’s indeed what we found.
"In these individuals, NK cells functioned better in the face of an inflammatory challenge, in addition to using energy more efficiently. Therefore, it’s as if exercise also trains the immune system."
According to the study’s findings, regular endurance training modulates the inflammatory response over time.
“When we compared the cells of trained older adults with those of non-athletes of the same age, we found that those with a history of endurance exercise had fewer inflammatory markers and more anti-inflammatory markers,” said Fábio Lira, a professor at the Faculty of Science and Technology (FCT-UNESP) and project coordinator.
"This means that, compared to non-athletic older adults, they had much better control of inflammation."
Lira said that the immune system can be influenced by several factors, such as sleep quality, diet and vaccination, as well as stress, a sedentary lifestyle and the use of immunosuppressive drugs, which reduce the activity of defence cells.
“Physical exercise is one of these factors that can benefit the immune system, and in this research project, we’re investigating how it can modulate the immune response over time."
In another study, the same group of researchers compared the immune response of young and master athletes before and after an acute exercise
session.
The results showed that the master athletes had a more controlled inflammatory response than the younger athletes.
The young athletes showed a more intense inflammatory response, while the older athletes showed a more regulated and controlled profile.
According to the researchers, this suggests that lifelong training can promote beneficial, balanced immune adaptation.
“Because they train regularly, their bodies are accustomed to dealing with inflammatory episodes, which requires more intense stimuli to generate significant long-term inflammatory responses," Dr Minuzzi said.
Dr Minuzzi points out that research on immune cells in athletes with a long training history has once again shown that decades of physical activity seem to 'train' the regulation of inflammation.
“The system doesn’t stop responding, but it avoids exaggeration. This is particularly interesting for a greater understanding of healthy ageing since disordered inflammatory responses are linked to several chronic diseases."
Or become our friend and subscribe to receive our fortnightly newsletter.