Societal inequality linked to reduced brain health linked to aging and dementia

Researchers from Trinity College Dublin have collaborated with international partners to determine whether societal inequalities affect the brain.

Their research paper “Structural inequalities linked to brain volume and the dynamics of aging and dementia networks across the Americas” was published In Natural aging on December 27 by an international team of researchers from the Multi-Partner Consortium to Expand Dementia Research in Latin America (ReDLat), from the Latin American Institute of Brain Health (BrainLat), the GIobal Brain Health Institute (GBHI) at Trinity College Dublin and other centers around the world.

The study reveals a direct link between structural inequalities – such as socio-economic disparities measured by a national-level index (GINI) – and changes in brain structure and connectivity associated with aging and dementia.

The study also sheds light on how societal inequalities are biologically rooted, particularly in underrepresented populations in Latin America and the United States.

Researchers found that higher levels of inequality are linked to reduced brain volume and disrupted connectivity, particularly in posterior temporal and cerebellar regions essential for memory and cognitive functions. These effects were more pronounced in Latin America, highlighting unique vulnerability of Latin American populations to macro-level socio-economic stressors.

The results also found that Latinos with Alzheimer’s disease experience the most severe impacts, suggesting that environmental demands linked to structural inequalities may exacerbate neurodegeneration in aging populations. On the other hand, the milder effects observed in frontotemporal lobar degeneration support the hypothesis of a more significant genetic influence on this pathology. Reduced brain volume and connectivity is frequently observed in patients with dementia and is associated with disease progression and severity.

Notably, the associations persisted even after accounting for individual factors such as education, age, gender, and cognitive ability, highlighting the independent role of macro factors in brain health. Living amid global 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, Ph.D. of the ReDLat consortium, said: “Our findings highlight the urgency of integrating not only individual social determinants of health into global brain health research, but also factors of macro-level exposure, such as social and physical variables. These results pave the way for future studies. explore the biological mechanisms linking global inequalities to aging and neurodegeneration.

Dr. Agustín Ibáñez, Ph.D., professor of global brain health at Trinity College and director of BrainLat and corresponding author, added: “This research highlights the critical role of structural factors. inequality in shaping brain health. Given that dementia rates are increasing particularly in low- and middle-income countriesour findings highlight the need for targeted interventions to address the root causes of brain health disparities, which appear region-specific.

The study calls for a multi-tiered approach to brain health equity, examining biological integration of other macro-level exposure factors beyond socio-economic inequalities.

These can include variables such as democratic governance, air pollution, migration, climate change and access to green spaces. Identifying and addressing these region-specific modulators could lead to targeted interventions that mitigate accelerated brain aging and reduce the burden of dementia in disadvantaged communities.