Multiple studies have shown that breastfeeding reduces the risk of breast and ovarian cancers in the mother. Girls that are breastfed as infants go on to have reduced risk for breast cancer later in life.
United States Breastfeeding Committee, Joan Meeks, MD, press release 8-28-08, in honor of breast cancer awareness month.; Enger SM, Ross RK, Paganini-Hill A, Bernstein L. Breastfeeding experience and breast cancer risk among postmenopausal women. Cancer Epidemiol Biomarkers Prev. 1998;7:365–369; Rosenblatt KA, Thomas DB. Lactation and the risk of epithelial ovarian cancer. WHO Collaborative Study of Neoplasia and Steroid contraceptives. Int J Epidemiol. 1993;22:192–197; Freudenheim, J. et al. 1994. Exposure to breast milk in infancy and the risk of breast cancer. Epidemiology 5:324-331