THE QUESTION Numerous studies have found that vigorous exercise can help stave off breast cancer. Might more-moderate physical activity, such as walking, have a similar effect?
THIS STUDY analyzed data on 73,615 post-menopausal women (average age, 63). About 9 percent were inactive, partaking in no leisure-time physical activity; for 47 percent, walking was their only exercise. Over a span of about 14 years 4,760 of the women were given diagnoses of breast cancer. Those who walked for at least an hour a day, even if they did no other exercise, were 14 percent less likely to have developed breast cancer than were less-active women. Women who exercised the most strenuously lowered their risk by 25 percent.
WHO MAY BE AFFECTED Post-menopausal women, the group most likely to develop breast cancer. An estimated one of every eight women will develop breast cancer at some point, and the risk increases with age, especially from middle age on.
CAVEATS Physical activity data came from the women’s responses on periodic questionnaires; the data did not include physical activity that may have been linked to their jobs. The findings might not apply to younger women.
FIND THIS STUDY October issue of Cancer Epidemiology, Biomarkers & Prevention.
The research described in Quick Study comes from credible, peer-reviewed journals. Nonetheless, conclusive evidence about a treatment's effectiveness is rarely found in a single study. Anyone considering changing or beginning treatment of any kind should consult with a physician.