Exercise Produces Hormone Changes That May Cut Breast Cancer Risk

The choice - physical activity cutting breast cancer risk or cutting off your breast(s).

A year-long aerobic exercise program for sedentary postmenopausal women produced hormone changes that may reduce the risk of breast cancer, researchers say.

"Exercise is a healthy, noninvasive, inexpensive and achievable lifestyle factor that can be used to reduce cancer risk," lead author Dr. Christine M. Friedenreich from Alberta Health Services, Canada, told Reuters Health by email. "Unlike some other options, e.g., chemoprevention, there are no harmful side effects and the benefits are considerable for many other chronic diseases as well."

In a randomized trial...in the Journal of Oncology, Dr. Friedenreich and her colleagues examined the effect of an aerobic exercise intervention on circulating estradiol, estrone, sex hormone-binding globulin, androstenedione, and testosterone levels in 320 women, ages 50 to 74.

The exercise program involved at least 45 minutes of aerobic exercise 5 days a week. In the control group, women merely maintained their usual level of activity.

Women in the intervention group exercised for a mean of 3.6 sessions per week for an average of 178.4 minutes/week. At 12 months, the exercisers had significant reductions in estradiol and free estradiol compared to controls, and significant increases in sex hormone-binding globulin.

Do you really need to think about it?