Benefits for the infant
Greater immune health
During breastfeeding, approximately 0.25-0.5 grams per day of secretory IgA antibodies pass to the baby via the milk.This is one of the most important features of colostrum, the breast milk created for newborns. The main target for these antibodies are probably microorganisms in the baby's intestine. There is some uptake of IgA to the rest of the body, but this amount is relatively small. Also, breast milk contains several anti-infective factors such as bile salt stimulated lipase (protecting against amoebic infections), lactoferrin (which binds to iron and inhibits the growth of intestinal bacteria).
[edit]Fewer infections
Among the studies showing that breastfed infants have a lower risk of infection than non-breastfed infants are:
In a 1993 University of Texas Medical Branch study, a longer period of breastfeeding was associated with a shorter duration of some middle ear infections (otitis media with effusion) in the first two years of life.
A 1995 study of 87 infants found that breastfed babies had half the incidence of diarrheal illness, 19% fewer cases of any otitis media infection, and 80% fewer prolonged cases of otitis media than formula fed babies in the first twelve months of life.
Breastfeeding appeared to reduce symptoms of upper respiratory tract infections in premature infants up to seven months after release from hospital in a 2002 study of 39 infants.
A 2004 case-control study found that breastfeeding reduced the risk of acquiring urinary tract infections in infants up to seven months of age, with the protection strongest immediately after birth.
The 2007 review for AHRQ found that breastfeeding reduced the risk of acute otitis media, non-specific gastroenteritis, and severe lower respiratory tract infections.
[edit]Reduced sudden infant death syndrome
Breastfed babies have better arousal from sleep at 2–3 months. This coincides with the peak incidence of sudden infant death syndrome. A study conducted at the University of Münster found that breastfeeding halved the risk of sudden infant death syndrome in children up to the age of 1.
[edit]Less diabetes
Infants exclusively breastfed have less chance of developing diabetes mellitus type 1 than peers with a shorter duration of breastfeeding and an earlier exposure to cow milk and solid foods. Breastfeeding also appears to protect against diabetes mellitus type 2,at least in part due to its effects on the child's weight.
[edit]Less childhood obesity
Breastfeeding appears to reduce the risk of extreme obesity in children The protective effect of breastfeeding against obesity is consistent, though small, across many studies, and appears to increase with the duration of breastfeeding.
A study has also shown that infants who are bottle-fed in early infancy are more likely to empty the bottle or cup in late infancy than those who are breastfed. "Bottle-feeding, regardless of the type of milk, is distinct from feeding at the breast in its effect on infants' self-regulation of milk intake." According to the study, this may be due to one of three possible factors, including that when bottle feeding, parents may encourage an infant to finish the contents of the bottle whereas when breastfeeding, an infant naturally develops self-regulation of milk intake.A study in Today's Pediatrics associates solid food given too early to Formula-fed babies before 4 months old will make them 6 times as likely to become obese by age 3. It does not happen if the babies were given solid foods with breast feeding.
[edit]Less tendency to develop allergic diseases (atopy)
In children who are at risk for developing allergic diseases (defined as at least one parent or sibling having atopy), atopic syndrome can be prevented or delayed through exclusive breastfeeding for four months, though these benefits may not be present after four months of age. However, the key factor may be the age at which non-breastmilk is introduced rather than duration of breastfeeding. Atopic dermatitis, the most common form of eczema, can be reduced through exclusive breastfeeding beyond 12 weeks in individuals with a family history of atopy, but when breastfeeding beyond 12 weeks is combined with other foods incidents of eczema rise irrespective of family history.
[edit]Less necrotizing enterocolitis in premature infants
Necrotizing enterocolitis (NEC) is an acute inflammatory disease in the intestines of infants. Necrosis or death of intestinal tissue may follow. It is mainly found in premature births. In one study of 926 preterm infants, NEC developed in 51 infants (5.5%). The death rate from necrotizing enterocolitis was 26%. NEC was found to be six to ten times more common in infants fed formula exclusively, and three times more common in infants fed a mixture of breast milk and formula, compared with exclusive breastfeeding. In infants born at more than 30 weeks, NEC was twenty times more common in infants fed exclusively on formula. A 2007 meta-analysis of four randomized controlled trials found "a marginally statistically significant association" between breastfeeding and a reduction in the risk of NEC.
