By Claire McCarthy, MD, FAAP
Breast milk is the natural food best designed to meet the needs of human infants. It has all the necessary nutrients, in the perfect amounts and is easy to digest. Beyond the nutritional benefits, here's another big plus: Breast milk helps build and strengthen your baby's immune system. Here's how.
Breast Milk: Food and Infection Fighter
Breast milk contains antibodies that can fight infection. These antibodies are present in high amounts in colostrum, the first milk that the breast secretes after childbirth. However, there are antibodies in breast milk that are present in the mother all the time the mother is nursing her baby. Through these antibodies, the mother can pass some protection against infectious diseases that she has had in the past, and those that she has while she is breastfeeding. Breast milk can literally give babies a head start in preventing and fighting infections.
Breast milk is also made up of proteins, fats, sugars, and even white blood cells that work to fight infection in a variety of ways. These especially help fight gastrointestinal infections, since breast milk goes directly to the stomach and intestines when consumed by babies. The different factors in breast milk work directly with the intestine before being absorbed and distributed throughout the body. This also lays the foundation for a balanced, protective immune system that helps identify and fight infections and other illnesses even after you stop breastfeeding.
Other factors in breast milk directly stimulate and strengthen the immune system. These include lactoferrin and interleukin-6, -8 and -10. These proteins help balance the immune system's inflammatory response, which is necessary for immune function but can be harmful in excess.
There is even evidence that nursing mothers who are vaccinated against COVID-19 can transmit antibodies to the virus through breast milk. Although not proven, these antibodies could help protect babies who are still too young to receive the vaccine. (Also read: Breastfeeding during the COVID-19 pandemic).
Is breast milk probiotic?
Breast milk also has "probiotic" factors. Some strengthen the immune system and others serve as a source of nutrition for the body's healthy bacteria, called the human microbiome. A healthy microbiome can play a lifelong role not only in preventing infections, but also in lowering the risk of allergies, asthma, obesity, and other chronic diseases.
With all of these immune-boosting factors in breast milk, it's no surprise that breastfed babies are less likely to suffer from ear infections, vomiting, diarrhea, pneumonia, urinary tract infections, and certain types of infections. meningitis. Research also shows that children who are breastfed for more than six months are less likely to develop childhood leukemia and lymphoma than those who receive formula. This may be in part because these types of cancer are affected by disturbances in the immune system.
To help keep babies healthy, communities can take steps to help mothers who choose to breastfeed their babies. These measures may include paid leave and giving employees space and time to express breast milk. If you are breastfeeding your baby or have questions, don't hesitate to talk to your pediatrician. If you are unable to breastfeed, or for personal reasons choose not to, talk to your pediatrician about other ways you can promote your baby's health.
About Dr. McCarthy:
Claire McCarthy, MD, FAAP is a primary medicine pediatrician at Children's Hospital Boston, assistant professor of pediatric care at Harvard Medical University, longtime editor of Harvard Health Publications, and official spokesperson for the American Academy of Pediatrics. Dr. Ella writes about health and parenting for the Harvard Health Blog, the Huffington Post, and many other online and print publications.