Major Study Finds Breastfeeding Reduces Mothers’ Risk of Developing Ovarian Cancer Later in Life

A new study led by researchers at Harvard Medical School finds that mothers who breastfeed their infants are 24 percent less likely to develop ovarian cancer later in life. Furthermore, the longer a mother breastfeeds, there is less of a risk that she develops ovarian cancer. The research found that women who breastfeed for 12 months were 34 percent less likely to develop ovarian cancer.

A total of 9,973 women with ovarian cancer and 13, 843 controls were included in the analysis. The prevalence of ever having breastfed ranged from 41 percent to 93 percent across studies. Mean breastfeeding duration ranged from 3.4 to 8.7 months.

Results showed an 18 percent reduction in risk for women who breastfed less than 3 months per live birth and a 34 percent reduction for women who breastfed 12 months or longer per live birth. The authors note that “statistically significant risk reduction associated with a mean breastfeeding duration of less than 3 months per episode suggests even a short duration of breastfeeding is beneficial.

The researchers conclude that “the World Health Organization recommends exclusive breastfeeding for at least 6 months and continued breastfeeding with complementary foods for 2 or more years. Our results support these recommendations.”

The full study, “Association Between Breastfeeding and Ovarian Cancer Risk,” was published on the website of the journal JAMA Oncology. It may be accessed here.