Physical Activity Lowers Risk of Breast Cancer


Recent, and consistent, physical activity significantly reduces the risk of developing breast cancer among postmenopausal women. Even modest physical activity is associated with reducing the risk. These resents were recently published in Cancer Epidemiology, Biomarkers and Prevention.

Data has suggested that physical activity reduces the risk of developing some cancers, including breast cancer. However, researchers have not been clear on how long the protective effects of activity persist, nor how rapidly they may confer a protective effect.

To further address these questions, researchers recently analyzed data from nearly 60,000 postmenopausal women who were followed between 1993 and 2005 through biennial questionnaires.

Women who had physical activity levels of 12 metabolic equivalent task-hours (MET-h) or greater per week within the previous 4 years had a significantly reduced risk of developing invasive breast cancer.
The benefit of physical activity in regards to reducing the risk of breast cancer leveled off at 12 MET-h/week, meaning that more physical activity did not confer a greater risk reduction for breast cancer.
The benefits of physical activity in regards to reducing the risk of breast cancer occurred within 4 years. Physical activity beyond 4 years did not provide the risk reduction of breast cancer.
The researchers concluded that “Our results suggest a decrease in risk associated with recent recreational physical activity even of modest levels.”

Reference: Fournier A, Dos Santos G, Guillas G, et al. Recent recreational physical activity and breast cancer risk in postmenopausal women in the E3N cohort. Cancer epidemiology, biomarkers and prevention. On-line publication. August 11, 2014. doi: 10.1158/1055-9965.EPI-14-0150. Available at: