Exercise Lowers Breast Cancer Risk, Helps Bones ... article excerpt
Posted Oct 04 2009 11:11pm
((( Bloomberg Dec 11 - 06 ))) Exercise may lower the risk of developing breast cancer after menopause, while also helping maintain bone density, according to two separate studies published in the Archives of Internal Medicine today.
Post-menopausal women who exercise frequently or vigorously are 14 percent less likely to develop breast cancer than those who don't, Mayo Clinic researchers said. In another study, scientists at Washington University School of Medicine said exercising to lose weight maintained bone density, while dieting alone made bones weaker.
Researchers said exercise reduced body fat, cutting a major source of estrogen associated with tumors in post-menopausal women. It also helped spur bone production, protecting against hip fractures and diseases such as osteoporosis.
``A common explanation given for the bone loss induced by weight loss is reduction in mechanical stress on the weight- bearing skeleton,'' scientists at Washington University School of Medicine said. ``Accordingly, the preservation of bone mineral density in the exercise group could be mediated through exercise-induced bone loading.''
The St. Louis, Missouri-based scientists studied 30 women and 18 men for a year. Those who restricted calories lost an average of 18 pounds (8.2 kilograms) and more than 2 percent of bone density in the lower spine, hip and upper femur, or thigh bone. Those who exercised lost an average of 15 pounds (6.7 kilograms) with no significant change in bone density.