Non-immunological benefits for baby:
Health and mental benefits for breastfed babies reach beyond a strengthened immunity in many ways that last throughout lifetime as well as some that are protective throughout infancy. The major protection in infancy conferred through breastmilk in the form of tryptophan. Tryptophan is a major amino acid component in the synthesis of melatonin hormone, which regulates sleep/wake cycles (circadian rhythm). This not only increases sleep per night by an average of 45 minutes, but more importantly, studies have shown that breastfed infants are more easily aroused from sleep at ages 2-3 months compared to formula fed infants, who are therefore at a greater risk of sudden infant death syndrome (SIDS).
Erythropoietin and prolactin are two other protective molecules transferred through breast milk. Erythropoietin stimulates the production of blood cells, which is not only a survival factor in neonates but also serves as a neuroprotective measure. Prolactin is beneficial to full-term babies as well as neonates, being a factor in lung and gut development as well as aiding in the intestinal absorption of nutrients. In a study of neonates, high prolactin blood levels was associated with fewer days on the ventilator, quicker transition to enteral feedings, and greater growth in length.
Other benefits for the baby are not due to a single supplement, but rather the holistic nutrients and growth factors that breast milk provides as well as the psychological development from mother-baby intimate contact. These developmental benefits are not as easily quantifiable, but multiple studies have confirmed them. One study found that infants who were exclusively breastfed for 6 months (rather than being introduced to solid foods at 4 months of age) crawled sooner and had a higher probability of beginning to walk by the age of one year. Tests conducted between the ages of one and a half years and two and half years of age revealed higher scores on the Bayley Scale of psychomotor development for breastfed (rather than bottle-fed) babies.
Benefits for mom:
There are also many benefits for the mother that may be considered to promote breastfeeding. Decreased estrogen levels when breastfeeding are responsible for a variety of personal and societal benefits. Lowered estrogen leads to fewer and lighter menstrual periods, called lactational amenorrhea, which also confers a natural contraceptive to space out births. Estrogen levels are also a key factor in the development of breast, endometrial, ovarian, and uterine cancer as well as arthritis. This period of reduced estrogen levels decreases cancer risk for breastfeeding mothers, by as much as 4.3% per year of lactation for breast cancer.
Estrogen decrease is also accompanied by prolactin and oxytocin increase. Both have been proven to protect the mother against stress by decreasing cortisol levels. This may contribute to the reduced chances of developing postpartum depression as a breastfeeding mother (measured by the edinburgh postnatal depression scale) which conferred statistically significant protection for up to four months. The actual act of breastfeeding, especially when mother-child contact is established early and initiating breastfeeding within one hour of delivery decreased chances of child abandonment by 50%! This finding may hold great opportunity to improve children’s lives, especially in areas where orphans are abundant.
Mothers may also reap the benefits of a decreased chance of smoking relapse after breastfeeding as well as the loss of postpartum weight (exclusive breastfeeding for six months caused an average weight loss of 12 kg in nursing mothers).