Gabe Mirkin, M.D.
Whenever I see people who are out-of-shape, I ask myself whether they are suicidal, uninformed, or they just don't care. Even eighty- and ninety-year-olds should be able lift weights, cycle long distances and compete in athletic competitions. Yet most people are in pathetic shape and suffer the consequences. An expert group appointed by the International Agency for Research on Cancer of the World Health Organization met in Lyon, France on February 2001 to evaluate the evidence for the role of weight control and physical activity in preventing cancer, and to identify priorities for research and for public health action in relation to the primary prevention of cancer. They concluded that limiting weight gain during adult life, thereby avoiding overweight and obesity, reduces the risk of postmenopausal breast cancer and cancers of the colon, endometrium, kidney (renal cell) and esophagus (adenocarcinoma). Limiting weight gain possibly reduces risk of cancer of the thyroid.
Weight loss among overweight or obese persons possibly reduces risks of these cancers, but no definite conclusion can be drawn. The working group also concluded that there was sufficient evidence for the role of physical activity in preventing colon and breast cancers, and limited evidence for the cancers of the prostate and endometrium. Some of these effects were independent of that of the weight control. Taken together, the working group considered that excess body weight and physical inactivity account for approximately a quarter to one-third of cancers of the colon, breast, endometrium, kidney (renal cell) and esophagus (adenocarcinoma). Thus being fat and out of shape appear to be the most important avoidable causes of these cancers. If you have been graining a few pounds each year, it is now time for you to start an exercise program and stop setting yourself up for cancer.