Breastfeeding: Nutrition and behavior

This chapter focuses on the functional properties of breastfeeding and its role in the mother-newborn relationship. The components of human milk make it an inimitable mixture and the optimal nutrition for newborns. Far from being only a source of nutritional elements, human milk has many favorable properties, most of them yet to be discovered. It has been shown that exclusive breastfeeding for 6 months in developing countries could prevent 13% of the global childhood mortality. This explains why the guidelines of both the World Health Organization and American Academy of Pediatrics strongly recommend 6 months of exclusive breastfeeding. Breastfeeding provides various physiological benefits for the child, such as protection against infections, development of physiological gut microbiota (eubiosis), acid-base balance, and optimal sleep quality. The positive effect of breastfeeding on neurobehavioral and cognitive development, especially of premature infants, is based on two potential mechanisms: the nutritional content of breast milk and the increasingly stronger mother-child bond, which indirectly involves cognitive growth. Behavioral postpartum changes are mediated by a vast array of neurochemicals, including oxytocin. Breastfeeding also reduces postpartum depression: the mechanisms involved are not completely understood, but it has been hypothesized that prolactin and oxytocin play significant roles. Their increasing levels are associated with a decrease of adrenocorticotropic hormone and cortisol levels. Endorphins plasmatic levels double during breastfeeding, suggesting a significant role, but conflicting results have been described.