Physical activity can lower the risk of developing 13 different types of cancer, according to a new study in JAMA Internal Medicine.
For the new study, researchers pooled data on 1.44 million people, aged 19 to 98 years, and examined a broad range of cancers, including rare malignancies. Participants, from the United States and Europe, were followed for a median of 11 years during which time 187,000 new cases of cancer occurred.
National Cancer Institute conducted the study as part of the National Institutes of Health and the American Cancer Society.
Here are five insights:
1. Leisure-time physical activity, as assessed by self-reported surveys, was associated with a lower risk of colon, breast and endometrial cancers.
2. Leisure-time physical activity is defined as exercise done at one's own discretion to improve or maintain health. The median level of activity in the study was about 150 minutes of moderate-intensity activity per week.
3. The study also found the risk of developing seven cancer types was at least 20 percent lower among the most active participants, that is, those in the 90th percentile of activity, as compared with the least active participants, those in the 10th percentile of activity.
4. Most associations between physical activity and lower cancer risk changed little when adjusted for body mass index. This suggests physical activity acts through mechanisms other than lowering body weight to reduce cancer risk.
5. The National Cancer Institute findings confirm and extend the evidence for physical activity having a beneficial impact on cancer risk.