In a detailed review of evidence from 20 studies one of us, Kathleen Wolin, reports that higher levels of physical activity protect against colon cancer (see study) and now the precursor lesions, colon polyps (see study) . The evidence is consistent across study design, approaches to assessment of physical activity, and the populations studied. Key features of this extensive review include the thorough search of the literature and use of state of the art statistical approaches to combine the evidence on activity and colon cancer risk.
By evaluating both colon polyps, the precursor lesion from which the majority if colon cancers develop, as well as colon cancer, Wolin is able to show that sustaining activity over the lifetime will lead to the greatest reduction in colon cancer. The parallel evidence from our previous work estimating the overall benefit of activity against colon cancer, sustained activity at the level of one hour of walking per day from age 30 to age 70 will reduce colon cancer by half compared to those who do not exercise at all (see table of results). This significant 50 percent reduction in new cases of colon cancer is a benefit that most of us can achieve. In addition, exercise reduces risk of heart disease and diabetes as well as other major chronic conditions.
Colon cancer is largely preventable. In addition to a healthy diet, maintaining a healthy weight and being physically active, screening significantly reduces the risk of both the diagnosis of colon cancer and death from colon cancer. See our related post,