Daily Walk May Cut Your Breast Cancer Risk
Study findings are good news for postmenopausal women, experts say
WebMD News Archive
By Kathleen Doheny
FRIDAY, Oct. 4 (HealthDay News) -- Older women who walk every day may reduce their risk of developing breast cancer. And those who exercise vigorously may get even more protection, according to new research.
The study of more than 73,000 postmenopausal women found that walking at a moderate pace for an hour a day was associated with a 14 percent reduced breast cancer risk, compared to leading a sedentary lifestyle. An hour or more of daily strenuous physical activity was associated with a 25 percent reduced risk, the study found.
This is welcome news for women who aren't very athletic.
"The nice message here is, you don't have to go out and run a marathon to lower your breast cancer risk," said study researcher Alpa Patel, senior epidemiologist at the American Cancer Society, which funded the study.
"Go for a nice, leisurely walk an hour a day to lower risk," Patel advised.
Breast cancer is the leading cancer among women. In the United States, about one in eight women will develop the disease in her lifetime.
The women who reported moderate exercise walked about three miles an hour, or about a 20-minute mile. The more vigorous exercisers participated in such activities as fast walking -- about 4.5 miles in an hour, the equivalent of a light jog, Patel said -- moderate cycling or lap swimming.
For the study, published online Oct. 4 in Cancer Epidemiology, Biomarkers & Prevention, Patel and her team identified more than 73,000 women past menopause who were enrolled in an American Cancer Society study on cancer incidence.
When they enrolled in 1992, the average age was nearly 63. The women completed a questionnaire about medical, environmental and demographic factors at the start and repeated the reports every two years between 1997 and 2009. The study participants also reported on their physical activity and time spent sitting, including watching television and reading, and reported any diagnosis of breast cancer.
During the follow-up, which was roughly 14 years, 4,760 women developed breast cancer.
The researchers compared the exercise habits of women who developed breast cancer and those who did not. About 9 percent never participated in physical activity, while about half reported walking as their sole activity.
Those who walked seven hours or more a week, even without engaging in other recreational physical activity, reaped protective benefits compared to those who walked three hours or less a week.
The message is encouraging, Patel said.
However, the study only found an association between moderate exercise and reduced breast cancer risk, not a direct cause-and-effect relationship.
While other studies have found that exercise lowered risk of breast cancer more for women with a lower body mass index (BMI) -- a calculation of body fat based on height and weight -- this study found the effect held regardless of BMI, weight gain in adulthood or use of postmenopausal hormone therapy.