Regular physical activity is a fundamental component of maintaining optimal health. Routine aerobic exercise can reduce the incidence of type 2 diabetes, obesity, cardiovascular disease, hypertension, high cholesterol and mood disorders. For years, researchers have questioned the effects of exercise on the development of cancer. The May 2006 issue of Carcinogenesis may shed some light on the picture. Preliminary evidence displayed in animals suggests that exercise can reduce the risk of skin tumors and pre-cancerous intestinal polyps.
Scientists at Rutgers, State University of New Jersey, and the University of Medicine and Dentistry of New Jersey conducted experiments in mice, focusing on the development of skin cancer. By exposing hairless mice to UV light and splitting them into groups with cages either containing a running wheel or devoid of one, they discovered that the mice with exercise took twice as long to develop skin cancer. Also the number of tumors was 32% less in the exercise group. A second study focusing on intestinal polyp development in mice over a 10 week period showed that voluntary wheel running exercise increased survival and decreased the number of polyps by 25% compared with mice without wheel access. The authors are uncertain what specific mechanisms are accounting for their findings, suggesting fat and lean muscle mass may play a role.
Whether these results apply to humans is difficult to predict. Until long-term, well designed studies are conducted we will not know. However, for those individuals who regular aerobic activity is not contrainidcated, these results may lend one more reason to get moving.
Posted by Dr. Jennifer Stagg on September 14, 2006 07:17 PM
