Oct 30, 2020 06:00:00

'Lactic acid' may be the cause of exercise suppressing cancer growth

Although

previous studies have shown that exercise reduces the risk of developing 13 different types of cancer, the mechanism by which exercise reduces the risk of developing cancer remains a mystery. Meanwhile, a new study shows that elevated levels of metabolites such as lactic acid after strenuous exercise may provide 'nutrition' to immune cells in the blood and strengthen immunity.

Cytotoxic T-cells mediate exercise-induced reductions in tumor growth | eLife
https://elifesciences.org/articles/59996

Exercise May Inhibit Cancer by Fuelling The Immune System, Study in Mice Suggests
https://www.sciencealert.com/exercise-might-delay-the-spread-of-cancer-by-fuelling-the-immune-system

In this study, researchers first divided cancer-affected mice into a 'rotary wheel exercise group' and a 'no physical activity group.' The results showed that regularly exercised mice had slower cancer growth and higher survival rates.

It is believed that the reason for the increased survival of mice in the exercising group was the ability to generate cytotoxic T cells that attack cancer cells, and mice lacking the ability to generate T cells promote cancer growth. It was not possible to suppress it and increase the survival rate. On the contrary, even in non-exercising mice, injecting T cells taken from exercising mice seems to have significantly improved the condition.

'This result shows that cytotoxic T cells become more effective against cancer cells through exercise,' the researchers say.

Researchers also believe that these changes are brought about by metabolites such as lactic acid. In mouse experiments, exercise-related metabolites increased up to 8-fold in post-exercise mice. This also significantly increased the amount of T cells in the blood taking up metabolites. Researchers believe that lactic acid and other substances may supply 'nutrition' to T cells in the blood and increase 'antitumor activity.'

In addition, an experiment in which lactic acid was administered to non-exercising mice in this study showed that T cells in the tumor increased and cancer growth was suppressed without exercise. I did. However, researchers also say that 'exercise has something more integrated than raising lactate levels.'

In addition to the mouse experiment, this study also conducted an experiment on eight healthy men. In the experiment, subjects performed a 30-minute bicycle exercise, and blood samples were taken before and after the exercise. The results confirmed that some metabolite levels were elevated, similar to mice, but further experiments were conducted to see if the metabolites strengthened the immune system and T cells killed the cancer. Is necessary.