LAUSR

All breastfeeding research faces the age-old challenge of innate selection bias. Girard et al1 recently used advanced quasi-experimental techniques to mimic randomization in combination with a large contemporary cohort, making a novel contribution to the field. This study has received significant press attention, mainly because the findings contradict previous researchers who reported positive relationships between breastfeeding and offspring cognitive development and/or performance. However, there is a crucial lack of discussion about a potentially critical contributing factor to these conflicting results: the exposure (formula-fed) group is not homogeneous. Infant formula feeding options are incredibly vast and differ between cultures. Combining all formula-fed infants into one single exposure diminishes … E-mail: bridget.young{at}ucdenver.edu