Longer breastfeeding duration leads to larger gray matter volume at age 10 years

A study directed by Dr. Christian Stephan-Otto, scientific coordinator of the Paediatric Image Computing Centre (PeCIC) of SJD Barcelona Children's Hospital - Institut de Recerca Sant Joan de Déu, and by Dr. Maria Portella, head of the Mental Health Research Group of the Institut d'Investigació Biomèdica Sant Pau, has analysed magnetic resonance images of some 8,000 children between the ages of 9 and 11 years in order to determine the relationship between breastfeeding duration and brain gray matter volume.

"We observed that breastfeeding duration is proportionally associated with a larger volume of a specific brain area in children from 9 to 11 years of age. This area comprises the inferior frontal gyrus and the lateral orbitofrontal cortex", according to Dr. Stephan-Otto, scientific coordinator of PeCIC, who goes on to say: "What's more, these larger volumes are associated with lower impulsivity levels in the children concerned."

"Our findings suggest that breastfeeding may have long-term effects on the development of the brain and the personality", states Christian Núñez, first author of the paper and researcher at the Institut d'Investigació Biomèdica Sant Pau, adding: "It should be pointed out that these brain regions play a very important role in decision-making and emotional self-regulation, among other functions."

Relationship between gray matter and cognitive performance

Gray matter is the brain substance that primarily contains neuronal cell bodies, dendrites and synapses, and it is responsible for processing sensory information, for controlling muscle movements, and for conscious thought. A larger gray matter volume may be associated with better cognitive performance and better capacity for processing sensory information.

Additionally, some studies have found that a larger gray matter volume is associated with better mental health and lower risk of developing neuropsychiatric disorders such as depression and anxiety. It should be noted, however, that the relationship between gray matter volume and brain function is not yet fully understood and that it continues to be a subject of research.

Larger gray matter volume in the brain's frontal cortex

The inferior frontal gyrus and the lateral orbitofrontal cortex are two important regions of the frontal part of the brain that carry out crucial functions in semantic processing, decision-making and emotional self-regulation. While previous research had already demonstrated the clinical and cognitive benefits of breastfeeding, this study has allowed observation of its effects on the brain. Likewise, it has been determined for the first time that a larger gray matter volume in this region has a direct influence on impulsivity levels in children, indicating that breastfeeding may be of fundamental importance in personality development.

"These results are just the beginning", says Dr. Maria Portella, co-coordinator of the study. "We hope to continue investigating how breastfeeding affects the brain and how we can use this information to improve child health. With this project we have laid the groundwork to show that a relationship does indeed exist in this respect, and we now need to achieve a better understanding of how this increase in gray matter volume relates to the cognitive and clinical benefits that breastfeeding is already known to possess."

The study was conducted by a research team of Sant Joan de Déu Barcelona Children's Hospital - Institut de Recerca Sant Joan de Déu, Institut d'Investigació Biomèdica Sant Pau, Hospital Clínic/IDIBAPS, NeNe Foundation, Autonomous University of Barcelona (UAB) and Networked Biomedical Research Centre (CIBER) - Mental Health. The project uses data from the Adolescent Brain Cognitive Development (ABCD) dataset, a large-scale longitudinal study funded by the US National Institute of Health.

Reference article: Núñez C, García-Alix A, Arca G, Agut T, Carreras N, Portella MJ, Stephan-Otto C. Breastfeeding duration is associated with larger cortical gray matter volumes in children from the ABCD study. J Child Psychol Psychiatry. 2023 Mar 22. DOI: 10.1111/jcpp.13790. Epub ahead of print. PMID: 36946606.

Image: Brain, the green areas indicate the brain regions that show a higher volume associated with the duration of breastfeeding.