The lack of economic resources deteriorates people’s physical and mental health and prevents them from leading a normal life and having access to universal rights such as work and decent housing. Now, new research has established a direct link between structural inequality – such as socioeconomic disparities measured through each country’s GINI index – and changes in brain structure and connectivity related to aging and dementia.
The study was carried out by a group of researchers from Trinity College Dublin in collaboration with international partners and its objective was to analyze how social inequality can affect our brain. The article that includes their conclusions is titled ‘Structural inequality linked to brain volume and network dynamics in aging and dementia across the Americas’ and has been published in Nature Aging.
The research was led by the Multipartner Consortium to Expand Dementia Research in Latin America (ReDLat), the Latin American Institute for Brain Health (BrainLat), the Global Brain Health Institute (GBHI) at Trinity College Dublin and other international centers and highlights how social inequities have a biological impact, especially on underrepresented populations in Latin America and the United States.
The results indicate that high levels of inequality are associated with smaller brain volume and reduced connectivity, especially in temporal-posterior and cerebellar areas that are essential for memory and cognitive function. These effects were more intense in Latin America, highlighting the greater vulnerability of these populations to macro-level socioeconomic stressors.
How an environment with social inequalities affects mental health
Additionally, the study reveals that Latinos with Alzheimer’s experience the most severe impacts and suggests that environmental demands related to structural inequality could aggravate neurodegeneration in older people. In contrast, the less significant effects observed in frontotemporal lobar degeneration reinforce the hypothesis of a greater genetic influence in this disorder. The reduction in brain volume and connectivity, frequently observed in patients with dementia, is associated with the progression and severity of the disease.
A key finding is that these associations persist even when considering individual factors such as education, age, sex and cognitive ability, underscoring the independent impact of macrostructural factors on brain health. Living in an environment with social inequalities affects brain health beyond the individual socioeconomic situation, showing the profound consequences of these disparities.
High levels of inequality are associated with smaller brain volume and reduced connectivity, especially in areas critical for memory and cognitive function.
In the opinion of the researchers, their findings highlight the importance of both individual social determinants and macrostructural factors – such as social and physical variables – in global research on brain health, and lay the foundations for conducting new studies that analyze the mechanisms. biological findings that relate inequality to aging and neurodegeneration.
They also consider that taking into account that dementia rates are increasing especially in low- and middle-income countries, it is necessary to adopt specific interventions to manage the causes of these inequalities that vary depending on the characteristics of each region.
The study proposes a multidimensional approach to achieving equity in brain health, examining other macrostructural factors beyond socioeconomic inequalities. These could include aspects such as democratic governance, air pollution, migration, climate change and access to green spaces. Identifying and addressing these specific factors could lead to the development of interventions aimed at mitigating accelerated brain aging and reducing the burden of dementia in disadvantaged communities.
