January 2013

Breastfeeding May Protect Against Ovarian Cancer

New research suggests that breastfeeding may reduce the risk for ovarian cancer.

A women's reproductive system has two ovaries, one on either side of the uterus. The ovaries, each about the size of an almond, produce eggs (ova) as well as the female sex hormones estrogen and progesterone.

Both babies and mothers gain many benefits from breastfeeding. Breast milk contains antibodies that can protect infants from bacterial and viral infections. Some of the nutrients in breast milk, such as protein and vitamins, help protect an infant against some common childhood illnesses and infections. Research indicates that women who breastfeed may have lower rates of certain breast and ovarian cancers.

The new study included 493 women with ovarian cancer and 472 women without ovarian cancer. The women answered a questionnaire regarding the breastfeeding length of time and the number of children breastfed.

Women who breastfed for a total of 31 months or more were significantly less likely to have ovarian cancer than women who breastfed for 10 months or less. Furthermore, women who breastfed three or more children had a significantly reduced risk of ovarian cancer, compared to women who breastfed only one child.

For more information about breastfeeding or ovarian cancer, please visit Natural Standard's Medical Conditions database.


  1. Natural Standard: The Authority on Integrative Medicine. 
  2. Su D, Pasalich M and Lee AH. Ovarian cancer risk is reduced by prolonged lactation: a case-control study in southern China. Am J Clin Nutr. 2013 Feb;97(2):354-359.

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