We had the same thought: We know exercise can reduce our risk of certain types of cancers, specifically colon cancer in men (and breast cancer in women). But new research, published in JAMA Internal Medicine, suggests the possible cancer-fighting benefits of exercise expand well beyond our previous beliefs—namely the number of cancers we can ward off, and the potential good exercise can do, even if you're overweight, The New York Times reports.
Researchers within the division of cancer epidemiology and genetics at the National Cancer Institute, Harvard Medical School, and more compiled 12 health studies conducted in the U.S. or Europe. In all, their comprehensive study included roughly 1.44 million people (the larger the scale, the more accurate the trend). These participants were asked whether they exercised, how often, and how vigorously. The researchers also looked into if and when, after each study’s start, the participants had been diagnosed with any type of cancer.
Men and women who moderately exercised—even if the time they spent exercising, like brisk walking, was slight—had a significantly smaller risk of developing 13 different types of cancer than people who were sedentary. Participants were less likely to suffer from breast, lung, and colon cancers (which we already knew); but they were also at a lower risk of developing tumors in their liver, esophagus, kidney, stomach, uterus, blood, bone marrow, head and neck, rectum, and bladder.
The top 10 percent of participants (a.k.a. those who spent the most time performing moderate or vigorous workouts each week) were as much as 20 percent less likely to develop most of the cancers in the study, compared to the 10 percent who were the least active, the researchers found.
Better news: The more people exercised, the greater their risk for developing any of these 13 cancers dropped. Still need a reason to run, bike, swim, or hit the gym? (We didn't think so.)