According to the results of a large European study published in the journal Cancer Epidemiology, Biomarkers & Prevention, women with the highest levels of household physical activity are less likely than the least active women to develop breast cancer.
Breast cancer is diagnosed in approximately 200,000 women annually in the U.S. alone. Due to its prevalence, researchers continue to evaluate ways to prevent or reduce the risk of women developing the disease.
Several studies have suggested that physical activity may reduce the risk of breast cancer, particularly postmenopausal breast cancer. Uncertainties remain, however, about the effects of different types of physical activity.
To explore the effects of different types of physical activity on risk of premenopausal and postmenopausal breast cancer, researchers evaluated information from a large study known as the European Prospective Investigation into Cancer and Nutrition (EPIC).
The current analysis involves more than 200,000 women (90,060 premenopausal women and 128,109 postmenopausal women). Study participants provided information about household, recreational, and occupational physical activity. Household physical activity included activities such as housework, home repair, gardening, and stair climbing. Recreational physical activity included walking, cycling, and other sports activities.
- Overall, 16% of the women were classified as inactive.
- Women with the highest levels of household activity had a reduced risk of both premenopausal and postmenopausal breast cancer. Among premenopausal women, those with the highest level of household activity were 29% less likely to develop breast cancer than women with the lowest level of household activity. Among postmenopausal women, those with the highest level of household activity were 19% less likely to develop breast cancer.
- By themselves, neither occupational nor recreational physical activity were linked with breast cancer risk.
The researchers conclude, “This study provides additional evidence for a protective effect of physical activity on breast cancer risk.” The researchers note that the protective effect of household physical activity “warrants further confirmation, but underscores the importance of more moderate types of activities for the prevention of breast cancer among middle-aged and older women.”
Reference: Lahmann PH, Friedenreich C, Schuit AJ et al. Physical Activity and Breast Cancer Risk: The European Prospective Investigation into Cancer and Nutrition. Cancer Epidemiology, Biomarkers & Prevention [early online publication] December 19, 2006.