Your Zip Code Might Influence Brain Health as You Age
New research indicates that the likelihood of receiving a dementia diagnosis can vary significantly depending on where you live in the U.S. This study explored how geographical location impacts dementia rates, and the findings are quite revealing.
Conducted by scientists at the University of California, San Francisco, the study was published recently in JAMA Neurology. The researchers examined medical records from veterans and discovered higher rates of dementia in several regions, especially in the Southeast and Northwest, although they did consider factors like income level. This points to potential long-standing regional differences contributing to dementia risk, according to the authors.
Dementia remains a significant public health challenge, particularly for older adults. Currently, over 6 million Americans are living with dementia, and a government-funded study projected this past February that up to 42% of individuals over 55 may develop it at some point in their lives.
The condition itself is complex, often resulting from a combination of environmental and genetic factors. Interestingly, senior author and neurologist Kristine Yaffe noted that there’s been limited research on how dementia risk varies geographically, especially at a national level. Fortunately, the team had access to a valuable dataset: deidentified records from veterans involved with the Veterans Health Administration, which is the largest integrated healthcare system in the country.
Yaffe mentioned in an email that the consistency of VA data collection nationwide made it perfect for their investigation. “No other national healthcare systems have this capability,” she asserted.
The study focused on the health of over 1.2 million randomly selected VA patients aged 65 and older without pre-existing dementia, tracking them for an average of 12 years.
When the researchers adjusted for age, they found that the Mid-Atlantic region, which includes states like Pennsylvania and Virginia, had the lowest dementia rates. Using this as a reference point, they identified that dementia rates were 25% higher in the Southeast (such as Kentucky and Tennessee), and 23% higher in both the Northwest (Idaho, Oregon) and Rocky Mountain states (Colorado, Montana). Other regions, like the South and Southwest, showed increases of 18% and 13%, respectively, with the Northeast slightly higher at 7%.
“These differences are quite significant, especially since all participants are veterans receiving care at VAHS,” said Yaffe, expressing her surprise at the size of these variations.
The researchers posited that elements like education levels, rural versus urban environments, and the prevalence of other health issues, such as heart disease, might account for some of the discrepancies they observed. Yet, even after factoring these in, the patterns remained largely unchanged. This suggests there might be other factors—less quantifiable by medical records—that explain why someone from New Jersey might face a lower risk of dementia compared to someone in Kentucky.
“The differences might be rooted in lifelong variances in aspects like the quality of education or social determinants of health,” Yaffe speculated.
The findings raise additional questions for further exploration, and the research team is eager to delve into them. If all goes well, insights gained could lead to new strategies for preventing dementia.
