Research released earlier this week offered evidence that the brains of poorer people age more rapidly than those of the better-off. The results raised a troubling question: Does that mean the marginalized are more likely to develop dementia?
A separate but complementary new study reports they are indeed.
Researchers who tracked the lives of more than 6,000 elderly folks in England found those who had accumulated the least wealth—that is, those who scored in the bottom rank on a five-point affluence scale—were 50 percent more likely to develop dementia than those in the top tier.
"Wealth late in life, but not education, was associated with increased risk for dementia, suggesting that people with fewer financial resources were at higher risk," writes a research team led by Dorina Cadar and Andrew Steptoe of University College London. Their study is published in the journal JAMA Psychiatry.
The researchers utilized data from the English Longitudinal Study of Ageing, which features a representative sample of the English population aged 65 and older. When they enrolled, participants reported the highest level of education they attained. Their wealth was calculated by the value of property, possessions, housing, savings, and investment.
Participants were then tracked for up to 12 years. The onset of dementia was noted by either a physician's diagnosis of the report of a family member or caregiver who filled out a questionnaire regarding their cognitive decline.
The researchers found dementia was positively associated with lower wealth, and this association was independent of education level. This link was still found after taking their physical health into account, and was stronger among the (relatively) younger participants—those born between 1926 and 1943—than those born between 1902 and 1925.
Cadar and her colleagues offer several possible explanations for this. Greater wealth, they note, "could represent a gateway to more mentally stimulating environments," including "greater digital literacy," as well as "broader access to cultural resources and behaviors (such as) reading, theaters, and social clubs."
In addition, people of lower socioeconomic status typically have poorer diets and exercise less then the better-off (often due to factors beyond their control). They're also at a heightened risk of depression. It's conceivable all of those factors could make dementia more likely, although more research is needed.
The fact education was "not a robust predictor" of dementia was a surprise, but the researchers note it may reflect the specific circumstances of these participants. This was the World War II generation, in which many people who would have gone to a university instead spent their early-adult years in the military.
Such people "may not necessarily have been able to access higher education," the researchers note, "but may have gained access to intellectually challenging jobs and growth opportunities after the war." That's key, since "high complexity of work" has been shown to reduce the risk of most types of dementia.
The researchers conclude that "public health strategies for dementia prevention should target socioeconomic gaps to reduce health disparities and protect those who are particularly disadvantaged." Cadar added that these results point to the need to "reduce health disparities and enhance engagement in sociocultural activities that ultimately contribute to a higher mental resilience or cognitive reserve."
What specifically that might look like is far from clear. But given the projected cost of caring for cognitively impaired seniors as the Baby Boomer generation ages, it deserves to become an urgent priority.