Leisure-time physical activity significantly reduces cancer risk

A study by Matthews et al, published in the Journal of Clinical Oncology, found that leisure-time physical activity significantly reduced risk of many cancers.

In this pooled study of 750,000 adults, engagement in recommended amounts of leisure-time physical activity (7.5-15 MET hours/week), an equivalent of 2.5 to 5.0 hours/week of moderate-intensity activity (eg, brisk walking), was associated with significantly lower risk for breast, colon (men only), endometrial, kidney, myeloma, and liver cancer and non-Hodgkin lymphoma (women only). The strength of associations for recommended amounts of physical activity versus none ranged from a 6% to 10% lower risk for breast cancer to an 18% to 27% lower risk for liver cancer. The shape of the dose-response curves varied by cancer type. Both moderate- and vigorous-intensity activity seemed to be associated with lower risk for colon, breast, and kidney cancer.