Study Unveils How Societal Inequities are Linked to Brain Health in Aging and Dementia

A research paper is published in Nature Aging by an international team of researchers from the Multipartner Consortium reveals a direct link between structural inequality—such as socioeconomic disparities measured by a country-level index (GINI)—and changes in brain structure and connectivity associated with aging and dementia.

Key findings

1.Researchers found that higher levels of inequality are linked to reduced brain volume and disrupted connectivity, especially in temporo-posterior and cerebellar regions essential for memory and cognitive function.

2.The findings also revealed that Latinos with Alzheimer’s disease experience the most severe impacts, suggesting that environmental demands linked to structural inequality may exacerbate neurodegeneration in aging populations. In contrast, the milder effects observed in frontotemporal lobar degeneration support the hypothesis of a more significant genetic influence in this condition. Reduced brain volume and connectivity are frequently observed in patients with dementia and are associated with disease progression and severity.

3. Notably, associations persisted even after accounting for individual factors such as education, age, sex, and cognitive ability, underscoring the independent role of macro-level factors in shaping brain health. Living in a context of aggregate inequality affects brain health regardless of your specific socioeconomic level, demonstrating the far-reaching consequences of societal disparities on the brain.

First author Agustina Legaz, PhD from the ReDLat consortium, said,

“Our findings emphasize the urgency of integrating not only individual social determinants of health into global brain health research but also macro-level exposome factors, such as social and physical variables. These findings pave the way for future studies exploring the biological mechanisms linking aggregate inequality to aging and neurodegeneration.”

The study calls for a multi-level approach to brain health equity, examining the biological embedding of other macro-level exposome factors beyond socioeconomic inequality.

Reference: Legaz, A., Altschuler, F., Gonzalez-Gomez, R. et al. Structural inequality linked to brain volume and network dynamics in aging and dementia across the Americas. Nat Aging (2024). https://doi.org/10.1038/s43587-024-00781-2