Cancer and Physical Activity

Abstract

Colon cancer is one of the most extensively studied cancers in relation to physical activity. A 2009 meta-analysis of 52 epidemiologic studies that examined the association between physical activity and colon cancer risk found that the most physically active individuals had a 24% lower risk of colon cancer than those who were the least physically active. A pooled analysis of data on leisure-time physical activity (activities done at an individual’s discretion generally to improve or maintain fitness or health) from 12 prospective U.S. and European cohort studies reported a risk reduction of 16%, when comparing individuals who were most active to those where least active. Incidence of both distal colon and proximal colon cancers is lower in people who are more physically active than in those who are less physically active. Physical activity is also associated with a decreased risk of colon adenomas (polyps), a type of colon polyp that may develop into colon cancer. However, it is less clear whether physical activity is associated with lower risks that polyps that have been removed will come back.