A new study has found that adults living in disadvantaged neighbourhoods may be at greater risk of faster brain ageing.
Experts believe this type of brain ageing and shrinkage could be an early sign of dementia, with middle-aged and older people living in areas with higher poverty levels and fewer employment and educational opportunities feared to be more at risk.
"Worldwide, dementia is a major cause of illness and a devastating diagnosis," said study author Amy J. H. Kind of the University of Wisconsin School of Medicine and Public Health in Madison. "There are currently no treatments to cure the disease, so identifying possible modifiable risk factors is important. Compelling evidence exists that the social, economic, cultural and physical conditions in which humans live may affect health. We wanted to determine if these neighbourhood conditions increase the risk for the neurodegeneration and cognitive decline associated with the earliest stages of Alzheimer's disease and dementia."
Researchers analysed 601 people with an average age of 59 from another study of Wisconsin residents. Those chosen had no memory or cognitive issues at the beginning of the study, but 69 per cent had a family history of dementia. Participants underwent an initial MRI scan, and over the course of 10 years, they were given additional brain scans every three to five years. These scans measured brain volume in areas typically affected by dementia, and participants were also given memory and thinking tests every two years.
While at the start of the study there was no difference in brain volume based on where the participants lived, at the end, the brain scans showed those who lived in disadvantaged neighbourhoods recorded a greater brain shrinkage and also faster decline in cognitive tests used to measure the risk of Alzheimer’s disease.
"Our findings suggest that increased vigilance by healthcare providers for early signs of dementia may be particularly important in this vulnerable population," said Kind. "Some possible causes of these brain changes may include air pollution, lack of access to healthy food and healthcare and stressful life events. Further research into possible social and biological pathways may help physicians, researchers and policymakers identify effective avenues for prevention and intervention in Alzheimer's disease and related dementia."
The study was published in the online issue of Neurology.