If you’re looking for motivation to be more physically active, you may find it in a recent study that shows, in addition to its other health benefits, exercise may reduce the risk of 13 types of cancer. In the study, conducted by researchers at the National Institutes of Health and the American Cancer Society and published in the May 2016 edition of the JAMA Internal Medicine, researchers examined the physical activity levels of 1.4 million people over an 11-year period. The study gathered specific information about whether, how vigorously and how often each participant exercised. Researchers also noted whether and when the participant was diagnosed with cancer.
Overall, participants who exercised more saw a 7 percent lower risk of developing any type of cancer than people who exercised less often. Those who were the most active (measuring in the 90th percentile) had a reduced risk of the following 13 cancer types, compared to the least active participants (measuring in the 10th percentile):
- Esophageal adenocarcinoma (42 percent lower risk)
- Liver (27 percent lower risk)
- Lung (26 percent lower risk)
- Kidney (23 percent lower risk)
- Stomach (22 percent lower risk)
- Endometrial (21 percent lower risk)
- Myeloid leukemia (20 percent lower risk)
- Myeloma (17 percent lower risk)
- Colon (16 percent lower risk)
- Head and neck (15 percent lower risk)
- Rectal (13 percent lower risk)
- Bladder (13 percent lower risk)
- Breast (10 percent lower risk)
“While we have always known that exercise is good for your health, this study shows a direct association between exercise and reduction in risk for very specific types of cancers, including some of the more aggressive types of cancers,” says Gentry Kozub, Physical Therapist at our hospital near Atlanta. “Moderate physical activity means getting your heart rate elevated to 60 percent of your estimated heart rate maximum. What this really means is increasing your heart rate to work up a sweat.” Kozub suggested calculating your target heart rate for moderate intensity by subtracting your age from 220, then multiplying that number by 60 percent.
The study suggested that moderate exercise may help regulate hormone levels associated with an increased cancer risk, while controlling insulin levels linked to cancer growths. “The recommendations for exercise from the study are realistic and achievable,” says Kozub. “One hundred and fifty minutes of moderate-intensity activity a week can be done in a variety of ways,” like walking, running, swimming, doing aerobics, cycling, using an elliptical machine and weightlifting. She recommends spreading the 150 minutes out over the week (five days a week for 30 minutes, or six days a week for 25 minutes, etc.).
The study also found that while being overweight is a well-known risk factor for cancer, exercise appeared to help obese participants lower their risks for the disease. On average, the study’s participants were slightly overweight. “I think people may often get discouraged from working out if they do not see instantaneous changes on the scale,” says Kozub. “But this study suggests that you still receive the reduced risk from developing certain cancers even if you do not lose weight.” If it’s been awhile since you’ve exercised or have pre-existing health conditions or concerns, you should talk to your doctor before starting a new exercise program, she adds.