Exercise may improve the immune system’s ability to fight cancer
Exercise may help to fight cancer by changing the inner workings of certain immune cells, according to an important new study in mice of how running affects tumors.
The study involved rodents but could also have implications for understanding how exercise might affect cancer in humans as well.
We already have considerable and compelling evidence that exercise alters our risks of developing or dying from cancers. In a large-scale 2016 epidemiological study, for instance, highly-active people were found to be much less likely to develop 13 different types of cancer than people who rarely moved.
Likewise, a review of past research released last year by the American College of Sports Medicine concluded that regular exercise may reduce our risks of developing some cancers by as much as 69 percent.
That analysis also found that exercise may improve treatment outcomes and prolong life in people who already have cancer.
But it is not yet fully clear how working out may affect tumors. Animal studies show that exercise lessens inflammation and may otherwise make the body’s internal environment less hospitable to malignancies.
But many questions remain unanswered about the interplay of exercise and cancer.
For the new study, which was published in eLife, scientists in Sweden decided to learn more by inoculating mice with different types of cancer cells and letting some of the rodents run, while others remained sedentary.
After several weeks, the researchers saw that some of the runners showed little evidence of tumor growth.002