A recent study from Duke University suggests that living in poorer neighborhoods might speed up brain aging and increase the risk of dementia, regardless of how much money you make or how educated you are.
The study proposes that focusing on these disadvantaged areas for dementia prevention efforts and urging doctors to consider where their patients live could help reduce the risk of dementia.
Risk of dementia
“If you want to prevent dementia, and you’re not asking someone about their neighborhood, you’re missing information that’s important to know,” the researchers explain.
Alzheimer’s disease stands as the leading cause of dementia, a condition that gradually strips individuals of their memories and cognitive abilities. Currently, approximately 58 million people worldwide suffer from dementia, a figure projected to surge to 150 million by 2050.
Despite the looming increase in cases and the significant emotional and financial burdens dementia imposes on individuals and families, effective cures or medications remain elusive.
Researchers are now shifting their focus towards dementia prevention rather than treatment, exploring lifestyle modifications such as dietary adjustments and regular exercise as potential avenues for mitigating the onset of this debilitating condition.
Where we live
While these lifestyle choices are well understood to affect the likelihood of developing dementia as we get older, the researchers wanted to understand whether where we live may be similarly important.
“We wanted to understand if there was a geographic patterning to dementia the way there is to longevity, like blue zones,” the researchers explain. “A lot of individual choices, like what you eat, what you do for fun, or who you spend time with, are constrained by where you live.”
In a big study involving 1.41 million people in New Zealand, the researchers checked out their medical records and where they lived to find patterns.
They looked at things like how much money people in different areas made, if they had jobs, their education level, and how easy it was for them to get around. Then, they rated each person’s address on a scale from one to ten based on these factors.
A stark finding
Just like smaller studies in the US and England, this one found something alarming: folks living in the toughest neighborhoods had a 43% higher chance of getting dementia over 20 years.
But here’s the kicker: could signs of brain trouble linked to rough neighborhoods show up way before memory issues kick in?
To find out, they dug into info from the Dunedin Study, which has been keeping tabs on nearly 1,000 Kiwis since they were babies. They looked at all kinds of stuff, like brain scans, memory tests, and how people rated their own smarts as they got older.
And what they found was pretty worrying: even by the time they hit 45, people from disadvantaged areas showed signs of weaker brain health, no matter how much money or education they had.
Poorer brain health
“It’s not just what personal resources you have, it’s also where you live that matters,” the researchers explain.
The study revealed various signs of poorer brain health among individuals residing in disadvantaged neighborhoods. These included fewer or smaller nerve cells in areas of the brain responsible for processing information, less efficient communication between brain cells, and increased instances of brain atrophy, possibly accompanied by microbleeds.
When researchers examined MRI scans of study participants at age 45, those from poorer neighborhoods exhibited visibly older brains, appearing approximately three years more aged than expected based on their chronological age. Moreover, they performed worse on memory tests and reported more difficulties with everyday cognitive tasks, such as following conversations or remembering familiar routes.
These findings underscore the association between living in disadvantaged neighborhoods and an elevated risk of dementia. While the precise mechanisms linking neighborhood deprivation to increased risk remain unclear, potential factors may include poorer air quality, reduced social interactions, heightened stress levels, and limited walkability commonly observed in such areas.
Addressing the heightened dementia risk linked to disadvantaged neighborhoods may not necessitate complex or expensive interventions. Simple, community-focused initiatives, such as implementing dementia prevention programs tailored to underserved areas or transforming vacant lots into small parks, could effectively channel resources to where they are most needed.
The authors emphasize the importance of early consideration of an individual’s neighborhood circumstances to identify and mitigate the accelerated aging of the brain and the associated risk of dementia.
