August 5th, 2011

By Theresa Hardy, CPNP, IBCLC

Newborn Nurse Practitioner and Lactation Consultant

Pediatrics, Christie Clinic

Have you ever wondered why babies love breastmilk so much? Or what’s in breastmilk that makes it so good for them? There are good reasons your infant grins up at you while they are nursing. Thirst quenching and sweet early in the feeding, high in fat and satisfying at the end of the feeding, uniquely designed to meet developmental needs, easily digestible; breastmilk has been termed the “perfect” food for infants. It contains necessary nutrients in easy to digest forms, while simultaneously providing both active and passive protection against illness. It is species specific, adapted over millennia to meet human infant nutritional needs while ensuring optimal growth, development and survival.

Breastmilk is a living fluid, providing a diverse array of bioactive substances to the developing infant during critical periods of brain, immune, and gut development. It has the ability to adapt to the needs of the growing baby; it changes throughout lactation and consists of exactly the right amount of proteins, carbohydrates and fats at the right time, adapting itself to the changing needs of growing babies.

Breastmilk is composed of 87% water, so your baby needs only breast milk to meet his fluid needs. The remaining 13% is made of fats, sugars, proteins, vitamins, minerals, enzymes and many other components. Multipurpose molecules are abundant in breastmilk. For example, the protein lactoferrin delivers highly absorbable iron while simultaneously depriving harmful bacteria from iron needed to survive and grow in the infant’s intestinal tract. Other multipurpose molecules in breast milk are oligosaccharides, sugars which promote the maturing of organs (the brain in particular), and prevent pathogenic germs from growing in the baby’s gut. Lactose (milk sugar), the main carbohydrate in breastmilk, is distinctly higher than in cow’s milk, making it very sweet, and providing the energy required for rapidly growing brains and the development of the infant's central nervous system.

Breastmilk is supremely digestible. While fully breast or breastmilk fed, it is not possible to form a hard stool, so baby doesn’t struggle with constipation. As baby’s gut matures, more and more of a breastmilk meal is digested, so much less waste means less dirty diapers. Actually, parents appreciate that more than the baby.  Parents also appreciate that breast milk stools are less, um, odiferous than those of formula fed babies.

In each breastfeeding, mother delivers millions of living white blood cells to her baby to help baby fight off all kinds of diseases, with diverse cells in breastmilk providing potent anti-inflammatory effects.  Immunoglobulins are abundant in human milk, which has immense protective value to the newborns immature immune system.  Newborn immunoglobulin protection is deficient and only increases slowly the first several months after birth.  Newborns do not absorb much of the primary immunoglobulin, SIgA. Rather, it “paints” the infants intestine to protect against respiratory and gastrointestinal tract infections caused by viruses and bacteria. Moreover, breastmilk “customizes” infant protection to illness. Before a mother has any symptoms of an illness, her body is making specific antibodies to protect the infant from that illness.

Breastmilk changes over time to meet the infants’ nutritional and developmental needs. An illustration is in those predictable late evening “fussies”. Baby doesn’t need a large volume morning feeding. What he needs, and gets, in the late evening, are smaller, more frequent feedings of higher fat milk to soothe his nervous system and make him feel fuller longer. He is ready for his first long sleep of the night. His parents certainly are!

Your baby is not interested in the latest research on the physiology of breastmilk, or that stem cells have been recently identified in his milk, or that he will be a healthier infant, child, and adult. He doesn’t know that the American Academy of Pediatrics recommends exclusive breastfeeding for the first six months, continuing for at least the first year of life and beyond for as long as mutually desired by mother and child. He doesn’t know that his parents will save approximately fifteen hundred dollars on formula alone for the first year of his life. He just knows he had a great feeding of milk made just for him, is content, and has drifted off to sleep in loving arms.

Tags: pediatrics, theresa hardy