According to the National Breast Cancer Foundation, 200,000 American women are diagnosed annually with breast cancer. Risk factors including age, number of first-degree relatives with breast cancer, race and hormone status influence are recognized risk factors for breast cancer. However, numerous environmental factors or lifestyle-related factors have also been shown to increase the risk for developing breast cancer.
Dietary Factors
One third of breast cancer risk may be related to diet and exercise, according to the Cornell University Sprecher Institute for Comparative Cancer Research. Since estrogen levels are a major factor in breast cancer risk, certain dietary modifications can lower estrogen levels. For example, increasing fiber intake and lowering fat consumption can result in lower levels of estrogen.
Physical Activity
Women who remain physically active throughout their lifetimes benefit from a 30 to 40 percent decreased risk of breast cancer. These findings are in accordance with a study by the Women's Health Initiative showing that physical activity among postmenopausal women involving walking about 30 minutes per day produced a 20 percent reduction in breast cancer risk. However, to reduce risk, the American Cancer Society suggests 45 to 60 minutes of moderate aerobic exercise most day of the week.
Exposure to Chemicals
Information provided by the Cornell University Sprecher Institute for Comparative Cancer Research suggests that chronic exposure to chemicals contained in everyday household products can have detrimental effects on health and increase the risk for developing breast cancer. Paints, various cleaning products, bleach and stain removers are among the more common products that contain harmful chemicals. Exposure includes inhalation, direct skin or eye contact and ingestion.These chemicals mimic the effect of estrogen in the body. Lifelong exposure to endogenous estrogen is a well established risk for breast cancer. Children and pregnant women are especially vulnerable and should exercise caution around these chemicals.
Additional Considerations
While the influence of obesity on breast cancer has a protective effect against breast cancer in premenopausal women, it is associated with an increased risk in postmenopausal women. This is thought to be due to the source of endogenous estrogens before and after menopause. In obese premenopausal women, ovarian estrogen production is inhibited by leptin which increases with fat stores leading to a decreased risk for breast cancer.
It is important to understand that many women in their postmenopausal years are overweight and are not capable of sustaining prolonged aerobic exercise to decrease their risk for breast cancer. Therefore, a low intensity program can be a part of the first initial transition from a sedentary lifestyle to becoming physically active.
Women that have not given birth or women who had their first child after the age of 30 may have a greater risk for breast cancer.
References
- National Breast Cancer Foundation: What is Breast Cancer?
- American Cancer Society: Breast Cancer
- "Exercise and Sports Sciences Reviews"; Physical Activity and Breast Cancer Risk: The Effect of Menopausal Status; Christine M. Friedenreich; October 2004
- Cornell University Sprecher Institute for Comparitive Cancer Research: Program on Breast Cancer and Environmental Risk Factors
- "The American Journal of The American Medical Association";Physical Activity and Mortality in Postmenopausal Women;L.H. Kushi et. al; April 1997
