Two systems compensate for the immature immune system of the newborn: placental transfer of maternal antibodies and the transmission of many immunoprotective and immunomodulating factors through breastfeeding. While the effects of placental transfer wane by six months of age, the delivery of immune support and maturation from breastmilk is available to the child the entire time he is breastfed. The benefits appear to last even beyond the age of weaning.

The American Academy of Pediatrics¹, the American Academy of Family Physicians², and the American College of Obstetrics and Gynecology³, all affirm that breastfeeding is protective of many diseases for the infant and mother. The health outcomes for infants and mothers ought to be measured using breastfeeding as the physiologic norm. The health risks for formula-fed infants compared to breastfeeding infants include⁴ an increased risk of diarrhea; 100% increased risk of otitis media; leukemia; 250% higher risk of hospitalization for a lower respiratory infection; 56% increased risk of Sudden Infant Death Syndrome; obesity; and type 1 and type 2 diabetes mellitus. Infants who are formula fed have a higher risk for dental malocclusion, and higher risk of a lower IQ. Premature infants who are formula fed have a substantially increased risk for necrotizing enterocolitis (NEC). The American Academy of Pediatrics recommends the use of banked donor human milk in the neonatal intensive care unit when sufficient mothers’ milk is not available to decrease the risk of NEC⁵.

For maternal outcomes, a history of lactation is associated with a reduced risk of type 2 diabetes^6,7, hypertension^8,9, stroke¹⁰, metabolic syndrome^11,12 and visceral body fat¹³. At least 7-12 months of lactation was found to reduce myocardial infarction risk in a large prospective cohort, and this association persisted after controlling for multiple lifestyle factors¹⁴. Women who do not breastfeed have a higher risk of breast^15,16,17 and ovarian cancer^18,19.

It has been estimated that if 90% of infants in the US were breastfed according to medical recommendations, 3,340 annual excess deaths would be prevented, 78% of which are maternal due to myocardial infarction (n = 986), breast cancer (n = 838), and diabetes (n = 473). Excess pediatric deaths total 721, mostly due to Sudden Infant Death Syndrome (n = 492) and necrotizing enterocolitis (n = 190). Medical costs total $3.0 billion, 79% of which are maternal. Costs of premature death total $14.2 billion^20,21.

In addition to the health benefits, breastmilk is always the right temperature, needs no mixing, is ready when infant is, and it’s free. It is species-specific and changes in composition for the age of the child. Mother’s milk supply will adjust to the infant’s needs. For example, bioactive proteins increase in breastmilk when an infant has an upper respiratory infection²². Mom doesn’t need to carry bottles, bags, and ice packs to go out. Families with breastfed children save money and create less waste for the environment²³.