Weight Gain Raises Cancer Risk in Study

A study of more than 95,000 nurses provides what may be the strongest evidence yet that women who put on a lot of weight during adulthood raise their risk of breast cancer substantially. Researchers, reporting on their findings in the Journal of the American Medical Assn., said the reason is that body fat increases the amount of estrogen in the bloodstream, and estrogen is thought to promote breast tumors. Women who were not taking estrogen after menopause increased their risk of breast cancer with every pound they gained after age 18.