Societal inequality may reduce brain health, finds study

Socio-economic disparities may cause changes in brain structure and connectivity associated with ageing and dementia, according to a study on Friday.

The study, led by an international team of researchers led by Trinity College Dublin, found that higher levels of inequality are linked to reduced brain volume.

It can also lead to disrupted connectivity, especially in temporo-posterior and cerebellar regions—crucial for memory and cognitive function.

The findings also revealed that people with Alzheimer’s disease face the most severe impacts.

This suggests that environmental demands linked to structural inequality may exacerbate neurodegeneration in ageing populations.

In contrast, the researchers observed milder effects in frontotemporal lobar degeneration. It may be due to a more significant genetic influence.

“Reduced brain volume and connectivity are frequently observed in patients with dementia and are associated with disease progression and severity,” said the team in the paper, published in the journal Nature Aging.

Notably, the team found a link even after accounting for individual factors such as education, age, sex, and cognitive ability. This underscores the independent role of macro-level factors in shaping brain health.

“This research highlights the critical role of structural inequality in shaping brain health,” said Dr Agustín Ibanez, Professor in global brain health at Trinity College.

“Considering dementia rates rise particularly in low- and middle-income countries, our findings emphasise the need for targeted interventions to address the root causes of brain health disparities, which appear to be specific to each region,” Ibanez added.

The findings stress the need to integrate social and physical variables along with individual social determinants of health into global brain health research.

These may 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 ageing and reduce the dementia burden in disadvantaged communities.