Summary: A new study reveals that higher levels of inequality—whether economic, environmental, or health-related—are associated with faster brain aging, particularly in countries with greater disparities. The research, involving over 5,000 participants from 15 countries, used advanced brain clocks based on deep learning to measure brain age gaps.
The study found that socioeconomic inequality, pollution, and diseases significantly contribute to accelerated brain aging, with the most pronounced effects observed in individuals with dementia and women in Latin American countries. These findings highlight the need for public health policies addressing environmental and social factors to promote global healthier brain aging.
Key Facts:
- Countries with greater inequalities exhibit faster brain aging, particularly in areas most affected by aging.
- Socioeconomic inequality, pollution, and diseases are key factors driving accelerated brain aging.
- Women in Latin American countries, especially those with Alzheimer’s, show greater brain age gaps.
Source: University of Surrey
Countries with greater inequalities – whether economic, pollution or disease-based – exhibited older brain ages, according to a study published in Nature Medicine, involving the University of Surrey.
The pace at which the brain ages can vary significantly among individuals, leading to a gap between the estimated biological age of the brain and the chronological age (the actual number of years a person has lived).
This difference may be affected by several things, such as environmental factors like pollution and social factors like income or health inequalities, especially in older people and those with dementia. Until now, it was unclear how these combined factors could either accelerate or delay brain ageing across diverse geographical populations.
In the study, a team of international researchers developed ways to measure brain ageing using advanced brain clocks based on deep learning of brain networks. This study involved a diverse dataset of 5,306 participants from 15 countries, including Latin American and Caribbean (LAC) nations and non-LAC countries.
By analysing data from functional magnetic resonance imaging (fMRI) and electroencephalography (EEG), the researchers quantified brain age gaps in healthy individuals and those with neurodegenerative conditions such as mild cognitive impairment (MCI), Alzheimer’s disease, and frontotemporal lobe degeneration (FTLD).
Dr Daniel Abasolo, co-author of the study and Head of the Centre for Biomedical Engineering at the University of Surrey, said:
“Our research shows that in countries where inequality is higher, people’s brains tend to age faster, especially in areas of the brain most affected by aging. We found that factors like socioeconomic inequality, air pollution, and the impact of diseases play a big role in this faster aging process, particularly in poorer countries.”
Participants with a diagnosis of dementia, particularly Alzheimer’s disease, exhibited the most critical brain age gaps. The research also highlighted sex differences in brain aging, with women in LAC countries showing greater brain age gaps, particularly in those with Alzheimer’s disease.
These differences were linked to biological sex and gender disparities in health and social conditions. Variations in signal quality, demographics, or acquisition methods did not explain the results. These findings underscore the role of environmental and social factors in brain health disparities.
The findings of this study have profound implications for neuroscience and brain health, particularly in understanding the interaction between macro factors (exposome) and the mechanisms that underlie brain aging across diverse populations in healthy aging and dementia.
The study’s approach, which integrates multiple dimensions of diversity into brain health research, offers a new framework for personalized medicine. This framework could be crucial for identifying individuals at risk of neurodegenerative diseases and developing targeted interventions to mitigate these risks.
Moreover, the study’s results highlight the importance of considering the biological embedding of environmental and social factors in public health policies. Policymakers can reduce brain age gaps and promote healthier aging across populations by addressing issues such as socioeconomic inequality and environmental pollution.
About this brain aging research news
Author: Dalitso Njolinjo
Source: University of Surrey
Contact: Dalitso Njolinjo – University of Surrey
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Brain clocks capture diversity and disparities in aging and dementia across geographically diverse populations” by Daniel Abasolo et al. Nature Medicine
Abstract
Brain clocks capture diversity and disparities in aging and dementia across geographically diverse populations
Brain clocks, which quantify discrepancies between brain age and chronological age, hold promise for understanding brain health and disease. However, the impact of diversity (including geographical, socioeconomic, sociodemographic, sex and neurodegeneration) on the brain-age gap is unknown.
We analyzed datasets from 5,306 participants across 15 countries (7 Latin American and Caribbean countries (LAC) and 8 non-LAC countries). Based on higher-order interactions, we developed a brain-age gap deep learning architecture for functional magnetic resonance imaging (2,953) and electroencephalography (2,353).
The datasets comprised healthy controls and individuals with mild cognitive impairment, Alzheimer disease and behavioral variant frontotemporal dementia. LAC models evidenced older brain ages (functional magnetic resonance imaging: mean directional error = 5.60, root mean square error (r.m.s.e.) = 11.91; electroencephalography: mean directional error = 5.34, r.m.s.e. = 9.82) associated with frontoposterior networks compared with non-LAC models.
Structural socioeconomic inequality, pollution and health disparities were influential predictors of increased brain-age gaps, especially in LAC (R² = 0.37, F² = 0.59, r.m.s.e. = 6.9). An ascending brain-age gap from healthy controls to mild cognitive impairment to Alzheimer disease was found. In LAC, we observed larger brain-age gaps in females in control and Alzheimer disease groups compared with the respective males.
The results were not explained by variations in signal quality, demographics or acquisition methods. These findings provide a quantitative framework capturing the diversity of accelerated brain aging.
