Exercise Helps Prevent Breast Cancer

Feb. 16, 2007 -- Exercise may help prevent breast cancer, and help those who do get it cope, two new studies show.

The first study, based on interviews with 15,000 women, shows that women who get more than six hours of strenuous exercise a week, and have no family history of breast cancer, may be 23% less likely to develop the disease than women who don't exercise at all.

The second study shows a 12-week group exercise program may boost mood and physical function in women with early-stage breast cancer.

The researchers don't promise exercise will prevent breast cancer, or blame breast cancer on a lack of exercise. Many factors affect cancer risk.

But, they do report exercise appeared to have benefits in protecting against cancer for women of all ages.

"We have found that exercise likely offers protection against breast cancer regardless of a woman's stage in life," researcher Brian Sprague, of the University of Wisconsin Paul P. Carbone Comprehensive Cancer Center, says in an American Association for Cancer Research (AACR) news release.

"The take-home message for women should be that it is never too late to begin exercising," Sprague says.

Breast Cancer Prevention Study

The study by Sprague, assistant professor Amy Trentham-Dietz, PhD, also of the Carbone cancer center, and others, appears in Cancer Epidemiology Biomarkers & Prevention.

For the study, the researchers interviewed more than 15,000 women in Massachusetts, New Hampshire, and Wisconsin by telephone.

Those interviewed included 6,391 breast cancer patients and 7,630 women without breast cancer. The women were 20-69 years old, roughly split between women 49 and under, those in their 50s, and those in their 60s.

Family History of Breast Cancer

Most had no family history of breast cancer, including the women with breast cancer themselves. While family history increases breast cancer risk, most patients don't have a family history of the disease.

During the 40-minute phone interview, the women noted whether they had participated in the following activities at some point in their lives since age 14: jogging/running, bicycling, calisthenics/aerobics/dance, racquet sports, swimming, walking/hiking for exercise, or other strenuous individual or team activities.

Most women, whether or not they had breast cancer, reported getting up to three hours of weekly strenuous exercise at some point since age 14.

But 461 women without breast cancer, and 332 with breast cancer, said they had exercised strenuously for more than six hours weekly at some point since age 14 -- typically when they were in their teens and early 20s.