Breastfeeding and Improved Cognitive/Noncognitive Development: Does the Effect Last Post Infancy and Toddlerhood? :

There are many great reasons to recommend breastfeeding as the preferred feeding method to new mothers, one of which has been the data from studies suggesting improved cognitive and noncognitive development in babies who breastfeed. But how valid and reliable is that evidence especially when you look up the road at the developmental trajectories of children who did and did not breastfeed? Girard et al. (10.1542/peds.2016-1848) investigated this question in approximately 8000 families in Ireland. Children in this cohort were randomly selected to participate by sharing parent and teacher reports and combining these with developmental assessments on  these children at 3 and 5 years looking at who did and did not breastfeed (based on maternal report of breastfeeding with propensity score matching).  While breastfeeding at first glance showed better developmental outcomes in cognitive and noncognitive development, once propensity matching occurred, only 1 of 13 developmental outcomes remained as being statistically significant—i.e. the level of hyperactivity being less for those children who breastfed for at least 6 months and even this disappeared by age 5.  Does this mean that breastfeeding not be recommended due to the lack of differences in development when compared to those who did not breastfeed for at least a half a year?  No—of course not, given the many other reasons why breastfeeding is best for a baby.  To further help explain the unexpected findings in this study and to note some limitations of the data findings as presented, Dr. Lydia Furman, an expert on lactation issues, provides an important commentary (10.1542/peds.2017-0150) to better frame this study in a larger context. Dr. Furman’s commentary adds a nice perspective that may enable you to appreciate the negative findings in this study but await confirmation in future studies before you can generalize the findings. In the meantime, hopefully this study will not by itself stop you from continuing to advocate as strongly as ever for mothers of new babies to breastfeed for at least six months if not the first year of life.