Physical Activity Lowers Breast Cancer Risk By Nearly 30%

Researchers from the University of North Carolina Gillings School of Global Public Health in Chapel Hill publishing in the journal CANCER have found that physical activity, either mild or intense and before or after menopause, may reduce breast cancer risk. As an aside, the scientists discovered that substantial weight gain may negate these benefits. The lead study investigator, Dr. Lauren McCullough and her team looked for a link between recreational physical activity, done at different time points in life, and the risk of developing breast cancer.

Study finds moderate exercise can lower breast cancer risk up to 30 percent
The study examined 1,504 women with breast cancer (233 noninvasive and 1,271 invasive) and 1,555 women without breast cancer who were 20 to 98-years-old. Participants were part of the Long Island Breast Cancer Study Project, an investigation set up to review possible environmental causes of breast cancer. Researchers determined that women who exercised either during their reproductive or postmenopausal years had a reduced risk of developing breast cancer.

The study found that women who exercise between ten and nineteen hours per week experienced a 30 percent decrease in breast cancer risk. Risk levels were reduced regardless of duration or intensity, meaning that a rigorous workout was not necessary to achieve positive results. Exercise seemed to lower the risk of hormone receptor positive breast cancer (ER or PR positive), which is the most commonly diagnosed tumor type among American women.

The study team highlighted the finding that increased body weight increased overall risk of developing breast cancer, regardless of hours spent exercising. Clearly, physical activity is important to lower risk, but gaining weight can negate the effect and is an independent risk factor. Dr. McCullough concluded "The observation of a reduced risk of breast cancer for women who engaged in exercise after menopause is particularly encouraging given the late age of onset for breast cancer." A daily 30 minute walk and maintaining a healthy body weight provide a significant shield against this insidious disease.