Studies have shown how getting the recommended amount of exercise can lower the risk of getting certain cancers. Now, Swedish researchers have found why there’s a link between exercise and slowing the rate of cancer.
A news release from the Karolinska Institutet in Sweden on Monday announced that scientists there have tested the hypothesis that physical activity stimulates the immune system resulting in the reinforcement of the body’s capacity to stop and hinder cancer from growing.
Researchers built on the hypothesis by reviewing the way the immune system’s cytotoxic T cells — white blood cells specialized in killing cancer cells — respond to exercise. They conducted the study using mice.
“The biology behind the positive effects of exercise can provide new insights into how the body maintains health as well as help us design and improve treatments against cancer,” Randall Johnson, professor at the Department of Cell and Molecular Biology, Karolinska Institutet, and the study’s corresponding author said in the news release.
Results of the study, which was published in the journal eLife, showed cancer growth slowed down in mice who were active and that physical activity changes the metabolism of the immune system’s cytotoxic T cells. That results in an improved ability to attack cancer cells.
To conduct the experiment, researchers split mice with cancer into two groups. One group was allowed regular exercise in a spinning wheel and the other group remained inactive. The result showed that cancer growth slowed and mortality decreased in the exercising mice compared with the ones that were inactive.
Afterward, researchers analyzed the importance of cytotoxic T cells by injecting antibodies that remove the T cells in trained and untrained mice alike. The positive effect of exercise on cancer growth and survival was removed by the antibodies. The researchers say this shows how significant the T cells are for exercise to aid in slowing cancer growth.
Additionally, cytotoxic T cells were transferred from active to inactive mice with tumors. That improved their outlooks compared to the mice who got cells from inactive rodents.
“Our research shows that exercise affects the production of several molecules and metabolites that activate cancer-fighting immune cells and thereby inhibit cancer growth,” Helene Rundqvist, senior researcher at the Department of Laboratory Medicine, Karolinska Institutet, and the study’s first author said in a statement. “We hope these results may contribute to a deeper understanding of how our lifestyle impacts our immune system and inform the development of new immunotherapies against cancer.”
To find out more about the study, including how exercise altered T cell metabolism, view the news release here.
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