Racism Experiences Tied to Worse Cognition

Experiences of racism were linked with lower memory scores and worse cognition in midlife and old age, especially among Black individuals, two observational studies showed.

"Racism is one of many causes of disparities in dementia," said University of California Davis epidemiologist Kristen George, PhD, MPH, presenting author of one of the studies at the 2022 Alzheimer's Association International Conference.

"If we really want to address dementia, we need to be able to name and measure racism," George told MedPage Today.

Older Black adults are twice as likely and Hispanic/Latino adults are one and a half times as likely to develop dementia as white individuals. But researchers have only recently begun to look for links between racism and cognitive decline, George noted. At this point, "we don't know a lot," she said.

George and colleagues evaluated 522 people without dementia in the Life After 90 study of Kaiser Permanente Northern California members. The average age of participants was 93 and 63% were women. Overall, 33% of participants were white, 23% were Black, 22% were Asian, and 15% were Latino. About half (46%) had mild cognitive impairment.

Participants were asked survey questions about discrimination experiences, such as being denied a bank loan, being mistreated by police, or being unfairly denied a promotion.

Based on survey responses, the researchers divided participants into three groups. Class 1 included 56 people, mainly white men, who said they had experienced workplace discrimination. Class 2 comprised 398 people who had experienced little or no discrimination, and Class 3 included 68 people who had experienced widespread discrimination and were all minorities.

Compared with Class 2, semantic memory was better for Class 1 (β 0.32) and worse for Class 3 (β -0.26), the researchers reported. Executive function was better for Class 1 (β 0.26), while Class 3 did not differ from Class 2. The researchers found no differences among the groups in verbal episodic memory.

The differences in semantic memory and executive function were "substantial," George noted. "We would have expected that Class 2 would have the best cognition of the group," she said. "But we found that Class 1 that reported job discrimination had better baseline cognition."

In the second study, researchers surveyed 1,095 middle-age adults in the Offspring Study in Manhattan about their experiences with interpersonal discrimination, institutional discrimination, and structural racism. In the cohort, 19% were white, 26% Black, and 55% Latino. Participants had a mean age of 55.

"On average, Black participants experienced interpersonal discrimination at least once every week," said presenting author Dominika Šeblová, PhD, of Columbia University Irving Medical Center in New York City, at a press conference. "Black participants were much more likely to attribute these experiences of discrimination to be related to their race, ancestry, or skin color than Latinx and white people."

The researchers found reliable relationships between daily experiences of racism and memory, Šeblová noted. The association of interpersonal racism with memory corresponded to scores that suggested a loss of 3 years of chronological age and was driven mainly by Black participants, she added.

"Our research is showing that structural racism, as a chronic lifetime stressor for minoritized people, is associated with poor memory in middle age," Šeblová said. "Our results suggest that efforts to increase systemic equality may also decrease risk for cognitive impairment later in life."

In an interview with MedPage Today, neuropsychologist Sid O'Bryant, PhD, of the University of North Texas Health Science Center at Fort Worth, praised the two studies.

"Both of them have excellent designs," O'Bryant said. "They were done really carefully and thoughtfully." Future studies that evaluate racism and cognitive changes over time may provide additional insight, he added.