Lifestyle in the Prevention and Management of Cancer: Physical Activity

Abstract

Cancer is the second leading cause of death in the United States, accounting for 1 in 4 deaths annually. It has been estimated that one third of all cancer deaths are related to overweight/ obesity, physical inactivity, and poor diet. Epidemiological studies have shown that regular physical activity reduces the risk for some types of cancer as well as postdiagnosis mortality. In studies examining the relation between regular physical activity and the risk of breast cancer, women who were the most physically active reduced their risk by at least 20%. Higher levels of recreational physical activity especially demonstrated greater risk reduction. Meta-analyses suggest that greater physical activity, especially leisure-time physical activity, may reduce the risk of colon cancer by 20% or more in men and women. Physical activity did not demonstrate an association with the risk for cancer of the rectum in either gender. Most studies report an inverse relation between physical activity level and risk for endometrial cancer. Although the estimates of risk reduction vary greatly across studies, the average reported risk reduction was about 30%. The benefit of regular physical activity in the prevention of prostate cancer is not as clear as with other types of cancer. There is some evidence, however, that physical activity may be protective of the more aggressive forms of the disease. Further research is needed to better quantify the specific components of physical activity required to reduce the risk for different cancers.