Abstract
OBJECTIVE: To investigate relationships of breastfeeding duration with brain structure and adiposity markers in youth and how these relationships are modified by neighborhood socioeconomic environments (SEEs). METHODS: This was a cross-sectional study of youth enrolled in the Adolescent Brain and Cognitive Development (ABCD) Study® (n = 7511). Mixed effects models examined associations of breastfeeding duration with global brain measures and adiposity markers, adjusting for sociodemographic, pre- and post-natal covariates. Stratified analysis was performed by area deprivation index (ADI) tertiles. RESULTS: Total cortical surface area (SA) (False Discovery Rate - FDR corrected P < 0.001), cortical (FDR corrected P < 0.001) and subcortical gray matter (GM) volume (FDR corrected P < 0.001) increased with increased breastfeeding duration. Body mass index (BMI) z-scores (FDR corrected P = 0.001), waist circumference (FDR corrected P = 0.002) and waist-to-height ratio (WHtR) (FDR corrected P = 0.001) decreased with increased breastfeeding duration. Breastfeeding duration was inversely associated with adiposity in youth from high- and medium- ADI neighborhoods, but positively associated with SA across ADI tertiles. CONCLUSIONS: In this cross-sectional study, longer breastfeeding duration was associated with lower adiposity indices, particularly in youth from lower SEEs and greater SA across SEE levels. Longer breastfeeding duration showed long-term associations with brain and body development for offspring. IMPACT: Building on previous findings that longer breastfeeding duration is associated with healthier weight gain, lower obesity risk, and brain white matter development in infancy, our results find longer breastfeeding duration to be associated with lower adiposity indices and greater cortical and subcortical gray matter volume, and cortical surface area during peri-adolescence. Children from lower socioeconomic environments (SEEs) demonstrated stronger negative associations of breastfeeding duration and adiposity indices, and children across SEEs showed positive relationships between breastfeeding duration and cortical surface area. Promoting breastfeeding, particularly among women from lower SEEs would confer long-term benefits to offspring.