Vigorous exercise cuts breast cancer risk in women
Many studies have found a link between regular exercise and breast cancer. Now a study from the National Cancer Institute provides some specifics regarding that relationship. The research, published today in BioMed Central's open access journal Breast Cancer Research, found that normal-weight women who exercise vigorously are about 30% less likely to develop breast cancer compared with normal-weight women who don't exercise vigorously.
The study examined more than 30,000 postmenopausal American women for 11 years. Vigorous exercise was defined performing such tasks as heavy housework (scrubbing floors, washing windows, heavy yard work) and participating in strenuous sports or exercise, such as running, fast jogging, competitive tennis, aerobics, bicycling on hills and fast dancing. In other words, activity in which you really work up a sweat.
The study also found that light housework (vacuuming, washing clothes, general gardening) and light exercise, such as walking, hiking, light jogging, bowling and recreational tennis) was not protective. Moreover, vigorous activity was only protective in lean or normal-weight women, not those who were overweight or obese. According to the lead author, Dr. Michael F. Leitzmann, physical activity may protect against breast cancer by reducing body mass, increasing immune function and decreasing chronic inflammation-all factors known to influence the disease risk.
-- Shari Roan
Photo credit: Robert Durell / Los Angeles Times