Is the "breast is best" mantra an oversimplification?
Recommendations about breastfeeding—absent critical analysis and removed from context—may overvalue its benefit. Here's a look at the evidence.
PRACTICE RECOMMENDATIONS
› Encourage breastfeeding for its potential to reduce the risk of acute otitis media, upper- and lower-respiratory infections, gastrointestinal infection, and dental malocclusion. A
› Promote breastfeeding for its potential to make a small difference in intelligence quotient and the incidence of overweight and obesity—but not for any other significant impact on long-term health. B
› Consider the needs and preferences of the individual when advocating breastfeeding so as to avoid potentially engendering maternal feelings of guilt and inadequacy. C
Strength of recommendation (SOR)
A Good-quality patient-oriented evidence
B Inconsistent or limited-quality patient-oriented evidence
C Consensus, usual practice, opinion, disease-oriented evidence, case series
From The Journal of Family Practice | 2018;67(6):E1-E9.
Long-term outcomes
Cognitive development. Several studies conducted in developed countries have linked breastfeeding to positive cognitive outcomes in children, including higher intelligence quotient (IQ).35,49-52
These effects are conflicting, however, in studies that include sibling analysis and ones that control for maternal IQ.8,35,43,52-54 In the 2013 WHO meta-analysis, breastfeeding was associated with an increase of 2.2 points on normalized testing when only high-quality studies were included.51 A 2015 meta-analysis identified 4 high-quality studies with a large sample size and recall time <3 years, which demonstrated a mean difference of 1.76 points in IQ (95% CI, 0.25-3.26) in childhood and adolescence.52 Although statistically significant, this modest increase is of questionable clinical benefit and of unknown duration.
Obesity. The relationship between breastfeeding and obesity later in life is debatable. A large, systematic 2014 review of 15 cohort and 10 cross-sectional studies found a significantly reduced risk of childhood obesity among children who were breastfed (adjusted OR=0.78; 95% CI, 0.74-0.81).55 However, the review included studies that controlled for different confounders, and smaller effects were found in studies in which more confounders were taken into account.
The 2013 WHO meta-analysis found a small (approximately 10%) reduction in the prevalence of overweight or obese children, but cautioned that residual confounding and publication bias were likely.51 At 6.5 and 11.5 years of follow-up, PROBIT failed to demonstrate a protective effect for exclusively or “ever” breastfed infants.56 Sibling analysis similarly fails to demonstrate a statistically significant relationship.8
Continue to: A 2015 meta-analysis of 23 high-quality studies...
