Regular physical activity protects women against breast cancer, according to a French study published in "Cancer Epidemiology, Biomarkers & Prevention". The activity does not even have to be particularly intensive; however, it does need to be regular.
Researchers at the Institut Gustave Roussy in Villejuif, France, analysed data obtained from biennial questionnaires completed by 59,308 postmenopausal women who were enrolled in E3N, the French component of the European Prospective Investigation Into Cancer and Nutrition (EPIC) study. The mean duration of follow-up was 8.5 years, during which 2,155 of the women were diagnosed with a first primary invasive breast cancer.
The study revealed that women who in the previous four years had undertaken physical activity equivalent to four hours of walking or two hours of cycling each week had a 10 percent decreased risk of invasive breast cancer compared with women who were less active. Women who undertook this level of physical activity between five and nine years earlier but were less active in the four years prior to the final data collection, did not have a decreased risk for invasive breast cancer.
The beneficial effects of regular physical activity were independent of body mass index, weight gain, waist circumference, and the level of activity from five to nine years earlier.
"Twelve MET-h [metabolic equivalent task-hours] per week corresponds to walking four hours per week or cycling or engaging in other sports two hours per week and it is consistent with the World Cancer Research Fund recommendations of walking at least 30 minutes daily," said first author Agnès Fournier. "We found that recreational physical activity, even of modest intensity, seemed to have a rapid impact on breast cancer risk. However, the decreased breast cancer risk we found associated with physical activity was attenuated when activity stopped."
Univadis
