Walking seven hours a week can lower breast cancer risk by 14 per cent, while vigorous physical activity every day can cut the risk by 25 per cent, a new study led by an Indian-origin researcher has claimed.
In the study of 73,615 postmenopausal women, those who were very active or walked for at least seven hours a week had a reduced risk for breast cancer, US researchers found.
"We examined whether recreational physical activity, specifically walking, was associated with lower breast cancer risk," said Alpa Patel, senior epidemiologist at the American Cancer Society (ACS) in Atlanta.
"Given that more than 60 per cent of women report some daily walking, promoting walking as a healthy leisure-time activity could be an effective strategy for increasing physical activity among postmenopausal women.
"We were pleased to find that without any other recreational activity, just walking an average of one hour per day was associated with lower risk of breast cancer in these women," Patel said.
After making adjustments to the data, the researchers determined that the observed benefits of physical activity and walking were not influenced by body type (BMI and weight gain) or hormonal status (postmenopausal hormone use and estrogen receptor status).
Women who engaged in at least an hour of vigorous physical activity every day had a 25 per cent lower risk for breast cancer, and those who walked for at least seven hours a week had a 14 per cent lower risk for breast cancer.
This is the first study to report a lower risk for breast cancer among this demographic associated specifically with walking, according to the authors.
The study included 73,615 postmenopausal women from a large cohort of 97,785 women aged 50 to 74 years, recruited between 1992 and 1993 to the Cancer Prevention Study-II Nutrition Cohort, a prospective study of cancer incidence established by the ACS.
The study was published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.