Summary: Growing up in poverty may impact a child’s brain development, specifically in the white matter tracts which facilitate communication between different brain regions.
The research, part of the large-scale Adolescent Brain Cognitive Development Study, links neighborhood and household poverty to these crucial aspects of brain structure.
This association appears to be partially mediated by childhood obesity and lower cognitive function, both more prevalent in children living in poverty.
Key Facts:
- The study reveals that neighborhood and household poverty may be linked to differences in the white matter tracts of the brain in children, crucial for the processing of information.
- Higher rates of childhood obesity and lower cognitive function observed in poverty-stricken areas partially explain the influence of poverty on white matter differences.
- The study is part of the largest long-term investigation into brain development and child health in the U.S., tracking almost 12,000 children for over a decade.
Source: WUSTL
A new study from Washington University School of Medicine in St. Louis suggests that growing up in poverty may influence the wiring of a child’s brain.
The study, published June 27 in JAMA Network Open, indicates a link between both neighborhood and household poverty and the brain’s white matter tracts, which allow for communication between brain regions. White matter plays a critical role in helping the brain process information.
The findings stem from the largest long-term study of brain development and child health conducted in the U.S. — the Adolescent Brain Cognitive Development (ABCD) Study, which was launched by the National Institutes of Health (NIH) in 2015. Washington University is a national leader in studies of the developing brain and is one of 21 study sites around the country participating in the ABCD Study, which is following nearly 12,000 children, beginning at ages 9 to 10, for at least a decade.
“White matter integrity is very important in brain development,” said first author Zhaolong (Adrian) Li, a neuroimaging research technician in the Department of Psychiatry.
“For example, weaknesses in white matter are linked to visuospatial and mental health challenges in children. If we can capture how socioeconomic status affects white matter early on in a child’s life, the hope is we can, one day, translate these findings to preventive measures.”
The researchers also found that childhood obesity and lower cognitive function may explain, at least partially, poverty’s influence on white matter differences. Generally, children who grow up in poverty have a higher risk of obesity and score lower on tests of cognitive function than their peers in higher income neighborhoods and households.
The latter could be due, in part, to limited access to enriching sensory, social and cognitive stimulation.
“Our finding that obesity and cognitive enrichment may be relevant mediators, if confirmed, would provide strong support for managing healthy weight and encouraging cognitively stimulating activities to support brain health in disadvantaged children,” said Tamara Hershey, PhD, the James S. McDonnell Professor of Cognitive Neuroscience and a professor of psychiatry and of radiology.
The research was conducted in the Neuroimaging Labs Research Center in the university’s Mallinckrodt Institute of Radiology.
White matter, the densely packed nerve fibers deep in the brain, gets its white color from the fatty substance that surrounds nerve fibers. The fatty coating is responsible for the rapid transmission of information along nerve cell tracts.
The organization and connectivity between these tracts support learning and proper communication across brain regions. Disruption in these communication pathways has been linked to physical challenges as well as worse mental health outcomes.
The scientists used the publicly available ABCD Study database, through which they were able to model water movement as an indicator of white matter integrity in the brain scans of 8,842 children ages 9 to 11.
Just like rocks, pebbles and boulders impact the flow of water in a river, diverse brain cell structures create barriers that hinder water diffusion. The researchers found less directional movement of water molecules in the brains of children living in poverty, signifying structural changes in white matter regions.
They also found higher water content in spherical spaces in the brain, which hinted at possible neuroinflammation in children who live in poverty.
A child’s environment is complex, involving both neighborhood and family influences. Disadvantaged neighborhoods suffer disproportionately from unemployment, poverty, and income disparity. Single-parent homes are more common, and residents are typically less educated, earn a lower income, and own less property.
“Our analysis revealed that neighborhood poverty is linked to white matter differences and putative immune cell presence. We found a similar link when looking at household socioeconomic status, taking into account annual income and parental education,” Li said.
“Wealth and income inequality are accelerating in the U.S.,” said co-corresponding author Scott Marek, PhD, an assistant professor of radiology and of psychiatry.
“We and others are starting to scratch the surface of how inequality may harm the developing brain and affect mental health outcomes.
“Our findings emphasize shifting away from the thinking that socioeconomics is a unitary construct. It’s not schools or parenting alone that matter for brain health. It’s likely the collection of many neighborhood and familial life factors.”
Hershey, who directs the Neuroimaging Labs Research Center and is a co-corresponding author, cautioned that the study only looked at one time point. Therefore, it is too soon to know if poverty triggered the brain differences seen in the study, she said.
However, the ABCD Study continues to track enrolled children through brain scans and cognitive testing with the potential for future long-term brain development studies in disadvantaged children.
“We hope this work encourages future studies to examine modifiable health risk factors in large and longitudinal samples that would one day translate to intervention,” Hershey said.
About this neurodevelopment research news
Author: Judy Martin Finch
Source: WUSTL
Contact: Judy Martin Finch – WUSTL
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Associations Between Socioeconomic Status, Obesity, Cognition, and White Matter Microstructure in Children” by Zhaolong (Adrian) Li et al. JAMA Network Open
Abstract
Associations Between Socioeconomic Status, Obesity, Cognition, and White Matter Microstructure in Children
Importance
Lower neighborhood and household socioeconomic status (SES) are associated with negative health outcomes and altered brain structure in children. It is unclear whether such findings extend to white matter and via what mechanisms.
Objective
To assess whether and how neighborhood and household SES are independently associated with children’s white matter microstructure and examine whether obesity and cognitive performance (reflecting environmental cognitive and sensory stimulation) are plausible mediators.
Design, Setting, and Participants
This cross-sectional study used baseline data from participants in the Adolescent Brain Cognitive Development (ABCD) study. Data were collected at 21 US sites, and school-based recruitment was used to represent the US population. Children aged 9 to 11 years and their parents or caregivers completed assessments between October 1, 2016, and October 31, 2018. After exclusions, 8842 of 11 875 children in the ABCD study were included in the analyses. Data analysis was conducted from July 11 to December 19, 2022.
Exposures
Neighborhood disadvantage was derived from area deprivation indices at participants’ primary residence. Household SES factors were total income and highest parental educational attainment.
Main Outcomes and Measures
A restriction spectrum imaging (RSI) model was used to quantify restricted normalized directional (RND; reflecting oriented myelin organization) and restricted normalized isotropic (RNI; reflecting glial and neuronal cell bodies) diffusion in 31 major white matter tracts. The RSI measurements were scanner harmonized. Obesity was assessed through body mass index (BMI; calculated as weight in kilograms divided by height in meters squared), age- and sex-adjusted BMI z scores, and waist circumference, and cognition was assessed through the National Institutes of Health Toolbox Cognition Battery. Analyses were adjusted for age, sex, pubertal development stage, intracranial volume, mean head motion, and twin or siblingship.
Results
Among 8842 children, 4543 (51.4%) were boys, and the mean (SD) age was 9.9 (0.7) years. Linear mixed-effects models revealed that greater neighborhood disadvantage was associated with lower RSI-RND in the left superior longitudinal fasciculus (β = −0.055; 95% CI, −0.081 to −0.028) and forceps major (β = −0.040; 95% CI, −0.067 to −0.013). Lower parental educational attainment was associated with lower RSI-RND in the bilateral superior longitudinal fasciculus (eg, right hemisphere: β = 0.053; 95% CI, 0.025-0.080) and bilateral corticospinal or pyramidal tract (eg, right hemisphere: β = 0.042; 95% CI, 0.015-0.069).
Structural equation models revealed that lower cognitive performance (eg, lower total cognition score and higher neighborhood disadvantage: β = −0.012; 95% CI, −0.016 to −0.009) and greater obesity (eg, higher BMI and higher neighborhood disadvantage: β = −0.004; 95% CI, −0.006 to −0.001) partially accounted for the associations between SES and RSI-RND. Lower household income was associated with higher RSI-RNI in most tracts (eg, right inferior longitudinal fasciculus: β = −0.042 [95% CI, −0.073 to −0.012]; right anterior thalamic radiations: β = −0.045 [95% CI, −0.075 to −0.014]), and greater neighborhood disadvantage had similar associations in primarily frontolimbic tracts (eg, right fornix: β = 0.046 [95% CI, 0.019-0.074]; right anterior thalamic radiations: β = 0.045 [95% CI, 0.018-0.072]).
Lower parental educational attainment was associated with higher RSI-RNI in the forceps major (β = −0.048; 95% CI, −0.077 to −0.020). Greater obesity partially accounted for these SES associations with RSI-RNI (eg, higher BMI and higher neighborhood disadvantage: β = 0.015; 95% CI, 0.011-0.020). Findings were robust in sensitivity analyses and were corroborated using diffusion tensor imaging.
Conclusions and Relevance
In this cross-sectional study, both neighborhood and household contexts were associated with white matter development in children, and findings suggested that obesity and cognitive performance were possible mediators in these associations. Future research on children’s brain health may benefit from considering these factors from multiple socioeconomic perspectives.
