Breast-Feeding Reduces Risk of Breast Cancer

According to the National Cancer Institute, the incidence of breast cancer has been on the rise for the past two decades. More than 200,000 new cases of breast cancer will be diagnosed in the United States this year, and almost 40,000 of these women will die from the disease. Women at risk for breast cancer include those who started their periods before age 12, who began menopause after age 55, who have never given birth to a child, who were over age 30 when they gave birth for the first time, who used postmenopausal estrogen replacement therapy for more than five years, or who have a mother or sister who have had breast cancer. The risk of developing breast cancer also increases with age. More than 77% of women diagnosed with breast cancer are age 50 or older at the time of their diagnosis. Although rare, men can also develop breast cancer, accounting for less than 1% of all cases in the United States.

In this new study, data from 47 studies done in 30 countries were examined to determine whether breast-feeding protected against breast cancer. Information on history and patterns of breast-feeding, aspects of childbearing and menopausal status were analyzed for almost 150,000 women of diverse cultural and ethnic backgrounds.

The risk of developing breast cancer decreased by just over 4% for every 12 months that a woman breastfed during her life. This was in addition to the 7% reduction in breast cancer observed with the birth of each child. The cancer-protective benefit of breast-feeding was observed, regardless of when a woman gave birth to her first child. Women with breast cancer had fewer births and breastfed less than did women without breast cancer. It is interesting to note that the proportion of women who had ever breast fed was the lowest in the United States (50%), where the incidence of breast cancer is relatively high, and highest in Japan and Scandinavia (more than 90%), where the incidence of the disease is lower. The average cumulative duration of breast-feeding in women with breast cancer and those without was 10 months and 16 months, respectively.

Breast-feeding may have other benefits, aside from protecting against breast cancer. Some studies suggest that infants who are breast-fed have stronger immune systems and develop fewer infections than formula-fed infants. Other studies show that breast-fed infants are less likely to develop asthma, eczema, and allergies. The American Academy of Pediatrics recommends at least 6 months of exclusive breast-feeding, although some research indicates that a longer duration of breast-feeding (such as 10 to 12 months) may further improve the health of the infant. The results of the new study suggest that mothers would also benefit from breast-feeding for a longer period of time. For more specific information with regard to evaluating breast cancer risk, consult a physician.

Darin Ingels, ND, MT (ASCP), received his bachelor’s degree from Purdue University and his Doctorate of Naturopathic Medicine from Bastyr University in Kenmore, WA. Dr. Ingels is the author of The Natural Pharmacist: Lowering Cholesterol (Prima, 1999) and Natural Treatments for High Cholesterol (Prima, 2000). He currently is in private practice at New England Family Health Associates located in Southport, CT, where he specializes in environmental medicine and allergies. Dr. Ingels is a regular contributor to Healthnotes and Healthnotes Newswire.

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