Breastfeeding duration is associated with larger cortical gray matter volumes in children from the ABCD study

Abstract

Background: Despite the numerous studies in favor of breastfeeding for its benefits in cognition and mental health, the long-term effects of breastfeeding on brain structure are still largely unknown. Our main objective was to study the relationship between breastfeeding duration and cerebral gray matter volumes. We also explored the potential mediatory role of brain volumes on behavior.

Methods: We analyzed 7,860 magnetic resonance images of children 9-11 years of age from the Adolescent Brain Cognitive Development (ABCD) dataset in order to study the relationship between breastfeeding duration and cerebral gray matter volumes. We also obtained several behavioral data (cognition, behavioral problems, prodromal psychotic experiences, prosociality, impulsivity) to explore the potential mediatory role of brain volumes on behavior.

Results: In the 7,860 children analyzed (median age = 9 years and 11 months; 49.9% female), whole-brain voxel-based morphometry analyses revealed an association mainly between breastfeeding duration and larger bilateral volumes of the pars orbitalis and the lateral orbitofrontal cortex. In particular, the association with the left pars orbitalis and the left lateral orbitofrontal cortex proved to be very robust to the addition of potentially confounding covariates, random selection of siblings, and splitting the sample in two. The volume of the left pars orbitalis and the left lateral orbitofrontal cortex appeared to mediate the relationship between breastfeeding duration and the negative urgency dimension of the UPPS-P Impulsive Behavior Scale. Global gray matter volumes were also significant mediators for behavioral problems as measured with the Child Behavior Checklist.

Conclusions: Our findings suggest that breastfeeding is a relevant factor in the proper development of the brain, particularly for the pars orbitalis and lateral orbitofrontal cortex regions. This, in turn, may impact impulsive personality and mental health in early puberty.

Keywords: Breastfeeding; behavior; brain structure; magnetic resonance imaging.