Through an examination of school segregation in the Jim Crow South, researchers are probing the link between education and brain health.
From the late 19th century to the mid-20th century, Jim Crow laws dominated Southern states in the country, legalizing racial segregation in everyday — including in public schools. These policies resulted in long-lasting inequities between Black and white older adults — including, researchers say, race-based disparities in brain health.
In a new study published in The Journals of Gerontology: Series B, researchers present a way to analyze education as a brain health factor that accounts for the institutionalized racism that Black older adults faced growing up in the Jim Crow South. This approach could explain up to about half of the disparity in the cognitive function between Black and white older adults, they say.
The recent study’s findings build on past research showing the geographic, social and cultural circumstances in which people were born or raised affects their cognitive health later in life. For instance, the recent study’s authors pointed to previous research of Black older adults living in Chicago; the study found that people who were born in the South or raised there until at least the age of 12 had a higher likelihood of performing worse on cognitive tests, compared to those in non-Southern regions. Further, some research suggests that perceptions among Black older adults of unfair treatment is linked with poorer cognitive test performances.
When it comes to assessing the link between education and cognitive health, one of the standard ways researchers measure education as a variable has been to look at “years of education.” But, according to recent study’s lead author Katrina Walsemann, an associate professor of public policy at the University of Maryland College Park, this measure comes with some downsides: It overlooks the political and cultural context of people’s education. She noted that segregation led to major differences in educational resources allocated to Black versus white students.
“A large proportion of older Black adults — people born in the 20s, 30s, 40s — grew up in the Jim Crow South when there were segregated school systems mandated by law,” Walsemann told Being Patient, “and Black schools were not provided the same level of investment as the white schools were.”
Consequently, historical documents show that annual school terms were on average up to two times shorter for Black students and they also received fewer days of schooling than their white counterparts. But education is closely linked with cognitive function, and scientists believe that education helps build people’s cognitive reserve, the brain’s resilience against aging and disease. Less time at spent at school means students have less opportunities to build their cognitive reserve, which may increase their odds of developing dementia down the road, Walsemann explained.
“If you’re going to school for fewer days out of the school year than another group of kids, then you don’t have the same amount of time to develop your cognitive function [and] cognitive reserve,” she said. “That could put you at risk later in life for impairment and dementia.”
Moving forward, accounting for these disparities could help expand researchers’ understanding of the factors behind the higher rates of dementia among Black older adults, compared to white older adults.
For the study, Walsemann and her colleagues collected data of U.S. older adults from the ongoing Health and Retirement study. The team linked this information to data of states and territories that legally mandated segregated schools. The final sample included 4,343 older adults who lived in the U.S. South when they were school aged, began primary school in or after 1919, and completed primary or secondary school by 1954.
The researchers then developed a measure of education that included not only years of schooling, but also race, state of residence, days of school attendance and school term length.
In line with past research, Black older adults had lower levels of overall cognitive function, and more specifically, episodic and working memory, compared to white older adults on average, the researchers observed.
Meanwhile, the team’s measure of education explained 41 to 55 percent of the Black-white disparity in overall cognitive function, and episodic and working memory. On the other hand, years of schooling accounted for 28 to 33 percent of racial disparity in these cognitive measures.
Ultimately, scientists hope that historically and culturally relevant factors of brain health, from education, to racism and discrimination, to health outcomes like comorbidities, can help inform people’s risk of cognitive impairment and dementia — and solutions to promote healthy cognitive aging.
