Apropos of ACOG’s new breastfeeding guidelines (see CBU post ), Attn notes Lancet’s publication of “Breastfeeding in the 21st century: epidemiology, mechanisms, and lifelong effect,” which includes 28 pooled analyses (meta-analyses) of studies of breastfeeding’s benefits in children and mothers.
In children, low- and middle-income countries reap the greatest reductions in mortality. However, breastfeeding prevents deaths in high-income countries as well because it reduces incidence of Sudden Infant Death Syndrome (SIDS) and necrotizing enterocolitis, a scourge in preterm infants. Breastfeeding also reduces morbidity, including fewer cases of diarrhea and respiratory infections—especially diarrheal and respiratory illnesses severe enough to require hospital admission—middle ear infections, and malocclusion. Longer periods of breastfeeding decrease the likelihood of being overweight. Breastfeeding appears to protect against Type 2 diabetes and possibly Type 1 diabetes as well. Breastfeeding is consistently associated with higher scores on intelligence tests, including in studies that adjust for potential confounding factors such as home stimulation. Finally, it is associated with a reduced incidence of childhood leukemia.
In mothers, studies find a protective effect against breast cancer that increases according to the number of months of breastfeeding and against ovarian cancer. Breastfeeding also has a duration-dependent beneficial effect on body mass index (BMI). Breastfeeding is associated with reduced likelihood of depression as well, although reviewers note that it seems more likely that depression affects breastfeeding than vice versa.
A section of the review summarizes the burgeoning body of research into the microbiome, the bacterial ecosystem of the intestines, gut, and breast, that is elucidating the mechanisms by which breastmilk confers its benefits on metabolism and immunity. Research is also discovering how breastfeeding can affect gene expression (epigenetics), which explains how breastfeeding provides long-term benefits. Conclude the reviewers:
Human breastmilk is therefore not only a perfectly adapted nutritional supply for the infant, but probably the most specific personalized medicine that he or she is likely to receive, given at a time when gene expression is being fine-tuned for life (p. 486).
The Take Away: Breastfeeding has unique and irreplaceable value. Maternity and pediatric professionals and society as a whole have the obligation to promote and facilitate breastfeeding. ACOG’s new breastfeeding support guidelines serve as a model set of strategies for achieving that goal.