Kaiser Permanente analysis finds people who attended schools in states with higher educational quality less likely to get dementia in later life
People attending schools in states with higher state-level educational quality are less likely to develop dementia in late life, according to a new Kaiser Permanente analysis published in JAMA Neurology. The study also found Black individuals had a higher likelihood of being exposed to lower state-level educational quality.
The authors suggest their findings provide insight into how unequal investment in high-quality education due to structural racism may affect dementia disparities, and how state-level investments in education may be important for brain health decades later.
“Our study adds to the evidence that older Black individuals were unequally burdened by lower state-level educational quality,” said lead author Yenee Soh, ScD, a research fellow with the Kaiser Permanente Division of Research. “Educational investments at the state level matter for dementia risk.”
Previous research mainly focused on educational quantity (such as years of schooling or highest degree attained) and risk of late-life dementia, but this may be insufficient to fully understand how education may influence dementia risk, Soh said. The researchers wanted to understand if and how educational quality was associated with dementia.
The study included 20,778 non-Hispanic Black and white adults born in the United States between 1902 and 1931. All were Kaiser Permanente Northern California (KPNC) members who participated in KPNC Multiphasic Health Checkups between 1964 and 1972 (the checkups collected information on demographics, health-related activities, and health indicators).
The authors used 3 metrics to gauge state-level educational quality: school term length, student-teacher ratio, and attendance rates. These metrics, which have been used in previous research, were consistently collected by states throughout the participants’ childhood years. The states’ measurements were categorized as low-, medium-, or high-quality. Meanwhile, participant dementia diagnoses were obtained from KPNC electronic medical records from 1997 to 2019.
Among individuals in the study, 19% self-reported as Black and 81% as white; 41% had less than a high school education. Seventy-six percent to 86% of the Black individuals were categorized into the low-quality state education groups, compared with 21% to 23% of white individuals.
The analysis found attending schools with medium-to-high state-level quality for student-teacher ratio, attendance rates, and school term length were associated with 8% to 21% lower risk of dementia compared with the respective lowest quality group. The magnitude of the risk did not differ based on Black or white race.
Educational quality and ‘cognitive reserve’
The authors suggested a few potential reasons for the association. Higher educational quality may contribute to “cognitive reserve” early in life, increasing the brain’s ability to cope with age-related changes and disease later in life. Higher educational quality also may increase literacy and numeracy; both are linked to higher educational attainment and income, which provides more access to resources that protect or enhance health. Educational quality may also be related to health factors that reduce dementia risk, such as lower likelihood of obesity, smoking, and high blood pressure, all of which are associated with dementia.
“This study underscores the importance of investing in education quality accessible by all for us to reach our goal of healthy brain aging for all,” said senior author Paola Gilsanz, ScD, an investigator with the Division of Research.
The authors said future research should explore how educational quality varies across other racial and ethnic groups, younger groups of people, and different regions of the U.S. to give a more complete view of the problem.
They also noted the potential role of school segregation — either explicit or economic — and the need to “disentangle how historical and modern forms of segregation are associated with dementia risk, particularly among racial and ethnic minority groups.”
Soh noted there could also be a role for individual-level factors, such as interpersonal discrimination or familial poverty, which may interact with the state-level educational quality that an individual experiences. The interplay of such factors needs to be further explored in future studies, she said.
The study was funded by the National Institute on Aging.
Additional co-authors were Charles P. Quesenberry, PhD, of the Division of Research; Rachel A. Whitmer, PhD, of University of California, Davis; Elizabeth Rose Mayeda, PhD, MPH, of University of California, Los Angeles; M. Maria Glymour, ScD, and Chloe W. Eng, MSPH, of University of California, San Francisco; Rachel L. Peterson, PhD, MPH, of University of Montana; and Jennifer J. Manly, PhD, of Columbia University Irving Medical Center.
# # #
About the Kaiser Permanente Division of Research
The Kaiser Permanente Division of Research conducts, publishes and disseminates epidemiologic and health services research to improve the health and medical care of Kaiser Permanente members and society at large. It seeks to understand the determinants of illness and well-being, and to improve the quality and cost-effectiveness of health care. Currently, DOR’s 600-plus staff is working on more than 450 epidemiological and health services research projects. For more information, visit divisionofresearch.kaiserpermanente.org or follow us @KPDOR.