Breastfeeding Reduces the Risk of Breast Cancer

It has long been believed that having lots of children and starting to give birth in your twenties, reduced a mother’s risk of developing breast cancer.

Having your first child after the age of 30 was always believed to increase the mother’s risk of developing breast cancer.

New research suggests that the benefit of reduced risk for breast cancer can include mothers who had their first child after the age of twenty-five…as long as they breastfeed. The most common forms of breast cancer involve tumors that express estrogen and progesterone receptors, but being a young first-time mother and having 4 or more children does not reduce the risk of developing rarer forms of breast cancer where the tumors don’t have these receptors. Breastfeeding, this research suggests, reduces the risk of developing both the common and rarer form of breast cancer.

“Breastfeeding may have a protective effect that negates the increased risk of breast cancer associated with late pregnancies,” said Dr. Giske Ursin, an associate professor of preventive medicine at the Keck School of Medicine at the University of Southern California, in a press release. “As more women may choose to delay pregnancy until after 25, it is important to note that breastfeeding provides protection against both estrogen and progesterone receptor positive and negative tumors.”

The study, “Parity, breastfeeding and breast cancer risk by hormone receptor status in women with late age at first birth—A Case Control Study,” was authored by Sarah J. Lord, Leslie Bernstein, Karen Johnson, Kathi Malone, Linda Weiss, Jill McDonald, and Giske Ursin.

The findings were presented on Monday at the annual meeting of the American Association for Cancer Research in Los Angeles.