Breastfeeding Lowers Your Risk of Breast Cancer

Pregnancy Reduces Estrogen Exposure

Mother breastfeeding her baby
Mother breastfeeding her baby. Torsten Schon @ Fotolia.com

Breastfeeding is not only healthy for your baby and a wonderful way to bond with him or her, but it has been shown to reduce a woman's risk of breast cancer. Furthermore, breastfed babies may have a reduced risk of developing certain cancers later in life.

How Breastfeeding Lowers Breast Cancer Risk

There are several theories about how breastfeeding can protect you from developing breast cancer. A 2017 review of 18 studies on the subject presents several possible explanations for the association:

  • Breastfeeding delays when women start menstruating again after giving birth. This reduces lifetime exposure to hormones such as estrogen, which are linked to an increased risk of breast cancer.
  • During and after lactation (which refers specifically to milk production in the breast), the breast sheds a lot of tissue during which it may also get rid of cells with damaged DNA that can give rise to cancer.
  • Breastfeeding may cause changes to the expression of certain genes in breast cells that make them more resistant to cancer-related mutations.

Research also suggests that children who are breastfed may have a reduced risk of developing certain cancers. A study in JAMA Pediatrics, for example, found that children who are breastfed for six months or longer may have a lower incidence of childhood leukemia.

How Long Should You Breastfeed?

While this is a very personal decision, it is believed that breastfeeding for one-and-a-half to two years over your lifetime will reduce your risk of breast cancer slightly.

Among the 18 studies reviewed in the 2017 report reviewed, 13 evaluated the effect of length of breastfeeding on cancer risk and concluded that for every five months of breastfeeding duration, there is a 2 percent lower risk of breast cancer.

The World Health Organization recommends that women breastfeed exclusively for a minimum of six months before introducing solid foods. This is a general recommendation, however, and unrelated to breast cancer prevention.

A Word From Verywell

Even if you have several pregnancies and breastfeed each baby, you may still develop breast cancer. Having breast tissue alone puts you at risk of breast disease. Perform a monthly breast self-exam to check for changes in your breasts, and keep in mind that most lumps are not cancerous. Benign lumps can be caused by a plugged milk duct, cyst, abscess, or fibroadenoma.

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