Socioeconomic status linked to white matter changes, which can shape brain heath in later life

A person’s level of social and economic status can shape their brain heath in later life, a study suggests. Research led by the University of Edinburgh found a connection between socioeconomic status and changes in the white matter of the brain—a known risk factor of cognitive decline and dementia in older age.

The world-first study analyzed data from nearly one million people to determine links between genetics and measures of occupation, income, education and social deprivation.

They found that three quarters of the genetic effects linked to each of these four socioeconomic measures are common across them all.

This common signal, termed the genetic factor of socioeconomic status, was then analyzed in 947,466 individuals.

Using a research technique called a genome-wide association study—which looks for links with genetic variations and traits in the brain and behavior—they found 554 regions in the human genome associated with socioeconomic status.

Using these data, they found that differences in socioeconomic status are a likely causal risk factor in the accumulation of white matter hyperintensities, a condition which could affect thinking skills, dementia risk, and brain function in later life.

Researchers say the findings show socioeconomic status may marginally help explain differences in brain health.

However, the majority of differences in cognitive health are explained by other environmental and social factors such as social conditions, specific policies and even luck, the team say.

An international team of researchers from the UK, Netherlands and Italy analyzed genetic data from nearly one million people from the age of 30 to older age.

A common genetic variation accounted for 9% of the differences in socioeconomic status, researchers said. The majority of the reasons why people differed in social and financial standing was not due to genetic factors, they added.

The team then studied MRI brain scans from a separate group of around 40,000 people to determine if socioeconomic status influences brain structure and whether brain structure, in turn, affects socioeconomic status.

They found evidence that a higher level of socioeconomic status leads to lower levels of white matter hyperintensities in the brain.

Researchers say the results show the value of genetic data in identifying the role of changeable environmental risk factors—such as socioeconomic status—in how our brains age.

The study lead, Dr. David Hill, an MRC Research Fellow of the University of Edinburgh’s School of Philosophy, Psychology and Language Sciences, said, “We found that there is a common genetic signal across measures of occupation, income, education, and social deprivation. By using this common socioeconomic status factor, we were able to capture aspects of socioeconomic status shared between the individual, the household, and the area in which one lives. This enabled us to better identify the causal effects of socioeconomic status on brain structure.”

Dr. Charley Xia of the University of Edinburgh’s School of Philosophy, Psychology and Language Sciences, said, “Studies examining traits such as socioeconomic status using genetic data can be easily conflated—we have not shown that brain health is genetically determined—rather that through the use of genetic data we were able to identify socioeconomic status as a modifiable environmental influence on brain health in older age.”

The study is published in Molecular Psychiatry. It contains an extensive FAQ to serve as a guide for understanding how genetic differences can be linked to socioeconomic status differences, and highlights the value of genetic data as a tool to examine environmental influences in human trait variation.

The study used data from the UK Biobank, a major genetic study into the role of nature and nurture in health and disease and the Social Science Genetic Association Consortium.

The research was carried out by researchers from the Universities of Edinburgh, Bristol, University College London, Modena in Italy, Vrije University in the Netherlands and Amsterdam University Medical Center.

A person’s level of social and economic status can shape their brain heath in later life, a study suggests. Research led by the University of Edinburgh found a connection between socioeconomic status and changes in the white matter of the brain—a known risk factor of cognitive decline and dementia in older age.

The world-first study analyzed data from nearly one million people to determine links between genetics and measures of occupation, income, education and social deprivation.

They found that three quarters of the genetic effects linked to each of these four socioeconomic measures are common across them all.

This common signal, termed the genetic factor of socioeconomic status, was then analyzed in 947,466 individuals.

Using a research technique called a genome-wide association study—which looks for links with genetic variations and traits in the brain and behavior—they found 554 regions in the human genome associated with socioeconomic status.

Using these data, they found that differences in socioeconomic status are a likely causal risk factor in the accumulation of white matter hyperintensities, a condition which could affect thinking skills, dementia risk, and brain function in later life.

Researchers say the findings show socioeconomic status may marginally help explain differences in brain health.

However, the majority of differences in cognitive health are explained by other environmental and social factors such as social conditions, specific policies and even luck, the team say.

An international team of researchers from the UK, Netherlands and Italy analyzed genetic data from nearly one million people from the age of 30 to older age.

A common genetic variation accounted for 9% of the differences in socioeconomic status, researchers said. The majority of the reasons why people differed in social and financial standing was not due to genetic factors, they added.

The team then studied MRI brain scans from a separate group of around 40,000 people to determine if socioeconomic status influences brain structure and whether brain structure, in turn, affects socioeconomic status.

They found evidence that a higher level of socioeconomic status leads to lower levels of white matter hyperintensities in the brain.

Researchers say the results show the value of genetic data in identifying the role of changeable environmental risk factors—such as socioeconomic status—in how our brains age.

The study lead, Dr. David Hill, an MRC Research Fellow of the University of Edinburgh’s School of Philosophy, Psychology and Language Sciences, said, “We found that there is a common genetic signal across measures of occupation, income, education, and social deprivation. By using this common socioeconomic status factor, we were able to capture aspects of socioeconomic status shared between the individual, the household, and the area in which one lives. This enabled us to better identify the causal effects of socioeconomic status on brain structure.”

Dr. Charley Xia of the University of Edinburgh’s School of Philosophy, Psychology and Language Sciences, said, “Studies examining traits such as socioeconomic status using genetic data can be easily conflated—we have not shown that brain health is genetically determined—rather that through the use of genetic data we were able to identify socioeconomic status as a modifiable environmental influence on brain health in older age.”

The study is published in Molecular Psychiatry. It contains an extensive FAQ to serve as a guide for understanding how genetic differences can be linked to socioeconomic status differences, and highlights the value of genetic data as a tool to examine environmental influences in human trait variation.

The study used data from the UK Biobank, a major genetic study into the role of nature and nurture in health and disease and the Social Science Genetic Association Consortium.

The research was carried out by researchers from the Universities of Edinburgh, Bristol, University College London, Modena in Italy, Vrije University in the Netherlands and Amsterdam University Medical Center.