The Association Between Breastfeeding Duration and Attentional and Cognitive Development in Infancy and Early Childhood.

While breastfeeding duration has been positively associated with later cognitive outcomes in childhood, behavioral assessments commonly used in early infancy may lack the sensitivity required to detect subtle differences. This study examined whether eye-tracking during infancy can be used to detect differences in attentional development related to infant feeding practices in a generally well-nourished population. Specifically, using data from the YOUth Baby & Child cohort (N = 2647) collected in Utrecht, the Netherlands, infant attentional disengagement was assessed around 5 months (4-6 months) and around 10 months (9-11 months) of age, alongside child receptive vocabulary around 3 years (2-4 years) and around 6 years (5-7 years) of age. While a positive association was established between breastfeeding duration and receptive vocabulary around 6 years of age, no association was established between breastfeeding duration and attentional disengagement at either timepoint. These findings suggest that effects of early-life nutrition on cognitive development in well-nourished infants do not extend to early attentional development or are too subtle to be picked up using eye-tracking. Future research could explore populations with greater developmental variability.