paying the bills, cannot afford healthy food or lack safe places to exercise, it’s hard to stay physically and mentally well.
Social factors also include education, and over the years studies have consistently linked higher education levels with a lower risk of dementia. In the current study, Yaffe’s team could only account for the typical education level in veterans’ ZIP codes — not their own attainment.
It all means that many factors, going back to early life experiences, may contribute to racial disparities in dementia rates, says Percy Griffin, director of scientific engagement at the Alzheimer’s Association.
“This is definitely a complicated issue,” Griffin adds.
The study — published April 19 in the Journal of the American Medical Association — used medical records from nearly 1.9 million veterans age 55 or older who received care between 1999 and 2019. The vast majority were men.
Over 10 years, 13% were diagnosed with dementia. The rate was highest among Hispanic vets, roughly 21 cases per 1,000 each year, followed by Black participants, at 19 per 1,000. White veterans had the lowest rate (11.5 per 1,000 each year), while Asian and Native American vets fell somewhere in between (just over 12 and 14 cases, respectively, per 1,000).
Once researchers accounted for other factors — such as whether vets had a history of high blood pressure, diabetes, stroke or brain injury — race was still an independent risk factor for dementia. That was particularly true for Hispanic and Black veterans.
In contrast, being Native American, per se, was not linked to a higher dementia risk, versus being white.
That is somewhat surprising, Yaffe says, and the reasons are unknown. But, she notes, Native American veterans may be different from Native Americans as a whole, and it’s not clear whether the findings would apply more broadly.
Yaffe also points to another issue: Studies have hinted that the standard tests used to evaluate memory and thinking do not perform equally for all races and ethnicities — raising the possibility of overdiagnosis.
“If someone fails a certain screening test,” Yaffe says, “that depends a lot on education, familiarity with testing, and English fluency. One could easily see biases around this. Someone might ‘fail’ the test and be considered to have dementia, but it may be due to some of these other things rather than a true failure.”
Griffin says that’s an important question, since dementia screening tools were validated on mostly white, more-educated groups.
More broadly, he says, it’s time for action.
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Eliminating dementia disparities
“We know disparities in dementia exist,” Griffin adds. “What are the steps going forward?”
He points to some that the Alzheimer’s Association has been taking, including partnering with groups such as the National Hispanic Medical Association and faith-based organizations to increase dementia awareness among health care providers and the public.
Griffin encourages older adults who are noticing changes in their memory to talk to their doctor sooner rather than later.
In addition, he says, a body of research suggests that “what’s good for the heart is good for the brain.” People can help protect their brain health through diet, regular exercise and managing conditions like high blood pressure and diabetes.