The benefits of breast milk for babies are numerous. Lower rates of childhood obesity, decreased incidence of asthma and even better brain development are all linked with drinking more of mother's milk in infancy, and despite decades of research and promising marketing claims, the formula industry has not caught up to mother nature in the milk department.

But even if technicians could develop a better food for infants, researchers are now realizing that skipping the lactation phase would be problematic for mothers' health. In fact, not breastfeeding after giving birth seems to put women at higher risk for breast and ovarian cancer, diabetes, cardiovascular disease and many other serious health conditions.

The mechanisms behind these increased risks are still being sorted out, but researchers think that by not engaging in the process that the body prepares for during pregnancy, many crucial systems can go out of whack. And the effects can last for decades after children are weaned. 

"The normal physiology is breastfeeding after pregnancy," says Alison Stuebe, an assistant professor in the Division of Maternal Fetal Medicine at the University of North Carolina in Chapel Hill, who describes breastfeeding as the fourth trimester of pregnancy. When women cannot or choose not to breastfeed, "there are myriad consequences, and we're just figuring them out," she says.


This image, based on medical imaging and computer rendering by the Visual MD, reveals the some of the biological systems affected during lactation, many of which are now thought to have lasting effects on a woman's health.

Costs of not nursing
About 85 percent of U.S. women have at least one child, and based on information about the virtues of breast milk for all those babies, most health agencies recommend that when biologically possible and safe women breastfeed infants exclusively for the first six months with the option of introducing complementary foods in addition to breast milk through 12 months.

Almost three quarters of women in 2005 (the latest year for which data are available) started breastfeeding their infants shortly after birth. By six months, however, only 42 percent of women were still feeding their babies any breast milk at all (with 12 percent still feeding exclusively breast milk at that point). Considering the improved health outcomes for the infants alone, the U.S. could save about $13 billion each year on medical costs if 90 percent of women nursed their infants exclusively for the first six months, according to an analysis by led by Melissa Bartick of the Department of Medicine at Cambridge Health Alliance and Harvard Medical School, published March 2010 in the journal Pediatrics. And that sum says nothing of the money that might be saved on health costs for mothers if they breastfed, which Bartick estimates would be "significant."

In a study of data from 139,681 postmenopausal women in the U.S., those who breastfed for less than 12 months during their reproductive years had a higher risk for cardiovascular disease, diabetes, hyperlipidemia and hypertension than women who had lactated for more than a year in total. For example, among women who had children, those who did not breastfeed had a 42.1 percent chance of developing hypertension, where mothers who breastfed for at least 12 months had a 38.6 percent chance, according to an analysis led by Eleanor Schwarz, an assistant professor of medicine, obstetrics, gynecology and reproductive sciences at the University of Pittsburgh, and published May 2009 in Obstetrics & Gynecology. For women who never become pregnant, many of their risks seem to be closer to those who have children and breastfed.

5 Comments

1. 1. Manatee593 08:58 AM 5/6/10

   Interesting article but what a shame that the banner ad above is for infant formula.

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2. 2. mimimccu 12:25 PM 7/9/10

   Agree about the poor choice of advertising! I wonder how much Enfamil paid for that one!

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3. 3. hmuccitelli 10:10 AM 5/2/11

   How about changing the title to "How Formula Feeding Harms Mothers and Babies"? If breastfeeding is the normal healthy state, then why do they say that breastfed moms and babies are healthier, not that formula fed babies are less healthy? In science you are supposed to compare the exception to the rule, not the other way around. This article uses language to mix messages. To the authors: So which is it? Make up your mind before you start writing.

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4. 4. hmuccitelli in reply to hmuccitelli 10:32 AM 5/2/11

   How you report your data DOES matter.

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5. 5. brynnscott 03:46 PM 2/9/12

   This is a touchy subject--some women are unable to breast feed, some women can breast feed but not produce enough to fulfill the needs of their child, some women may want to continue breast feeding but are unable to manage because they need to return to work and don't have a pump or a place to store the milk safely. So the language in the article is based around encouraging those who can instead of remonstrating those who can't.

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