Low income affected the rate of brain aging
A team of medics from Switzerland studied the results of brain diagnostics and compared them with the socio-economic conditions in which people lived, namely the level of family income. The team from the Department of Population Epidemiology at the University Hospital of Geneva and from the University of Lausanne and the University of Geneva (Switzerland) tried to answer this question. The results of their study are published in The Journal of Neuroscience.
People from lower-income families showed signs of advanced aging of the brain's white matter. The researchers found greater mean diffusivity (transport of H2O molecules in biological tissues), lower density of neurites, or axons, which are the long cylindrical outgrowths of the nerve cell, as well as less myelination (increased lipid content and decreased water content of the nerve sheaths) and lower iron levels.
"The association of household income with mean diffusivity was mediated by neurite density and myelination; mean diffusivity partly mediated the association of income with cognitive ability. Household income moderated the correlation of white matter microstructure with cognitive function, so higher mean diffusivity, lower myelination or neurite density were only associated with worse cognitive ability in people from lower-income households," the authors of the research paper noted.
At the same time, participants living in more affluent families maintained cognitive function even with higher mean diffusion, lower myelination or neurite density, the researchers stressed. According to them, these findings provided a more detailed understanding of how socioeconomic differences affect the brain and cognitive function.
A little earlier than the article by Swiss medics in the journal Alzheimer's & Dementia, a scientific paper by scientists from Duke University (North Carolina, USA) was published. Their analysis of medical records and addresses of 1.41 million New Zealanders showed that accelerated brain aging and the development of dementia - dementia - is influenced by living in poor, disadvantaged neighborhoods.
By the age of 45, such people had significantly worse brain health, and this was regardless of personal income or education level. Based on MRI scans, those living in the most deprived areas had brains that looked three years older than they should be given their present age. They also performed worse in memory tests and experienced more problems in everyday life - for example, losing their bearings in familiar places.