By Erika Costanzo, Breastfeeding Counselor Human milk is a dynamic, living substance. It is full of immune boosting antibodies and healthy bacteria, which are needed by infants and children in different amounts and formulations as they grow. Human milk changes as the needs of the nursing child evolves. Human milk is composed of water, carbohydrates, fats, proteins, vitamins, minerals, antibodies, immune cells, stem cells, hormones, enzymes, growth factors, and hundreds of different beneficial bacteria. Scientists studying human milk are continuing to discover components we are not aware of yet. Early milk, called colostrum, provides newborns with powerful immune protection and coats the digestive tract to guard against unwanted bacteria. Colostrum is thick and often golden in color, and helps babies pass meconium, those first sticky, tar-like stools. After a few days, the lactating parent's body begins to produce a transitional milk, which is thinner in texture, generally lighter in color, and higher in volume than the smaller amounts of colostrum that the baby needed right after birth. At about two weeks postpartum, transitional milk continues to evolve into its final state, known as mature milk. This is the way we typically think of human milk, in its mature state. Human milk provides all of the nutrition that babies need for the first 6-12 months of life. As children transition to more solid foods and take in less milk, the volume produced decreases, but the concentration of immunological components increases, providing the concentrated protection that curious, exploring toddlers need. In addition to evolving as children grow older, human milk changes throughout the day, with higher serotonin levels in the evening when babies are preparing to sleep. Human milk also responds to the environment, producing immune factors that fight off bacteria the body detects, either from mom’s exposure or through the feedback mom’s body gets from baby’s saliva at the breast. During a growth spurt, when babies may feed more frequently, the volume and fat content of milk increases in order to help babies grow. There is also some interesting research focused on the differences in the milk the body produces for female and male babies. According to the Mayo Clinic, “there's no known age at which breast milk is considered to become nutritionally insignificant for a child” (Mayo Clinic, 2020). |