Breastfeeding Benefits Your Baby’s Immune System

By: Claire McCarthy, MD, FAAP

Breast milk is the food naturally designed to nourish babies. It delivers all the nutrients your newborn needs in the right amounts, and it's easy to digest. Another bonus: breast milk helps strengthen your baby's immune system. Here are more amazing facts about breastfeeding, immunity and your child's health.

Breast milk provides your baby with antibodies that help fight infection. The first milk that that comes out of breasts after giving birth–known as colostrum–is especially rich in antibodies. As you continue to nurse, your baby will take in more antibodies, which helps them resist illness and infection now and in the future.

Along with antibodies, breast milk delivers proteins, fats, sugars and even white blood cells that work to fight infection in many ways. As breast milk enters your baby's system, infection-fighting elements work with your baby's intestine even before nutrients are broken down and absorbed into the bloodstream. The result is a more balanced immune system that helps your child's body recognize and fight illness more effectively.

Other elements in breast milk directly stimulate and support your baby's immune response, too. These include lactoferrin and interleukin-6, -8 and -10, proteins that help moderate the inflammatory response that happens when your immune system encounters a threat—for example, a virus or bacterial infection. Inflammation is a natural part of immune functioning, but too much inflammation can be harmful, so keeping things balanced is essential for your child's health.

You may have heard about probiotics, the "good" bacteria that are present in the healthy digestive systems of kids and adults. These useful bacteria strengthen your child's immune response by offsetting the growth of unfriendly organisms that can cause infections and inflammation.

Breastfeeding gives your baby a steady supply of probiotics, strengthening their gut microbiome. Research suggests that this, in turn, reduces risks for chronic health conditions including:

Studies also show that breastfed babies are less likely to suffer from infections such as:

urinary tract infections

some forms of meningitis

In addition, research reveals that children who nurse for 6+ months are less likely to develop childhood leukemia and lymphoma than formula-fed children. This may be because these two types of cancer, which affect the blood, are linked with disruptions to a child's immune system.

The American Academy of Pediatrics (AAP) recommends breastfeeding as the healthiest way to feed newborns and infants. With the right resources and support, most parents who choose to breastfeed will be able to successfully manage any challenges they encounter. Breastfeeding parents enjoy health dividends as well, including:

Metabolic support for returning to their pre-pregnancy weight

Reduced chances for cardiovascular disease and stroke

Lower risks for ovarian and breast cancer

If you're considering breastfeeding, or you have questions about your baby's nutrition and health, don't hesitate to ask your pediatrician. And if you can't breastfeed or decide it's not right for you, rest assured that your pediatrician will support you with healthy feeding strategies that will nurture your child's growth and development.

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Claire McCarthy, MD, FAAP is a primary care pediatrician at Boston Children's Hospital, an Assistant Professor of Pediatrics at Harvard Medical School, a senior editor for Harvard Health Publications and an official spokesperson for the American Academy of Pediatrics. She writes about health and parenting for the Harvard Health Blog, the Huffington Post and many other online and print publications.