May 28, 2021
This article is an excerpt from issue 41 of Today’s Research on Aging.
Expanded educational opportunities during the early part of the 20th century are related to recent declines in dementia prevalence among both older non-Hispanic Black and non-Hispanic white adults, Mark D. Hayward and colleagues show.1 Their review of Health and Retirement Study (HRS) data from 2000 to 2014 documents significant declines in dementia prevalence for both older non-Hispanic Black and non-Hispanic white adults. Non-Hispanic Black adults ages 65 to 74 experienced the steepest decline. Analysis demonstrates that higher levels of educational attainment are related to the recent declines in dementia prevalence.
Findings by Hayward and colleagues echo numerous studies that link more schooling with a lower risk of dementia. Researchers theorize that education may directly affect brain development by creating a cognitive reserve (stronger connections among brain cells) that older adults can draw on if their memory or reasoning ability begins to decline with dementia. They also suspect that people with more education may be better able to compensate or adapt in the face of disrupted mental functions. In addition, education brings multiple advantages: people with more education tend to have healthier lifestyles, higher incomes, better health care, and more social opportunities—all associated with better brain health.
In a related study based on HRS data, Mateo P. Farina and colleagues use modeling techniques to simulate dementia prevalence among different racial and ethnic groups and find lower dementia prevalence in both Black and white Americans with more education, especially at older ages.2
However, they also find that Black adults who have not finished high school are at much greater risk of dementia than other groups, even white adults without a high school diploma (see figure). In fact, dementia prevalence for Black adults at age 65 without a high school diploma is similar to that of Black adults at age 75 with a high school education and white adults at age 85 with at least some college.
FIGURE. Older Black Americans Who Did Not Graduate From High School Face a Higher Risk of Dementia
Implied Dementia Prevalence Among Black and White Older Adults by Age and Education Levels, 2000-2014
Source: Mateo P. Farina et al., “Racial and Educational Disparities in Dementia and Dementia-Free Life Expectancy,” The Journals of Gerontology: Series B, Psychological Sciences and Social Sciences 75, no. 7 (2020): Figure 1.
These findings show the importance of intersectionality—the overlapping of social disadvantages, compounding the impact—in explaining health disparities (see below). “When race and socioeconomic status are combined in empirical research, they intersect in ways that typically exaggerate disparities because of the distinct racialized and class-based exposures that affect health outcomes,” Farina and colleagues conclude.
Vicki Freedman and colleagues identify large and growing disparities in dementia risk by race/ethnicity, which could slow progress in cutting dementia levels. Among those ages 70 and older, dementia prevalence in the non-Hispanic Black population is estimated at 12.7%, compared with 8.4% among non-Hispanic white adults.3
Closing gaps in educational attainment is one way to reduce this Black-white disparity in dementia prevalence. But more research is needed to “unpack the ‘black box’ of how early-life education decreases later-life dementia risk,” writes Kenneth M. Langa.4
Bereavement also may be contributing to racial disparities in dementia risk, Debra Umberson and colleagues show.5 Their analysis of HRS data provides evidence that experiencing the death of a child prior to midlife (before a parent reaches age 40)—a tragedy more common for Black parents than for white parents—is related to increased dementia risk. The researchers find links between child loss and a variety of factors that may raise dementia risk, including depression, diminished earnings, alcohol consumption and smoking, and cardiovascular disease.
Researchers also note the need for better methods to measure dementia prevalence across different groups. Estimates of the Black-white gap in dementia prevalence differ across data sources based on whether they determine dementia using cognitive tests (via those in the HRS) or physician diagnosis (via Medicare claims). Yi Chen and colleagues find that older Black adults and individuals with less than a high school education are more likely than older white adults and college-educated individuals, respectively, to be identiﬁed as having dementia based on cognitive tests only.6 In contrast, dementia ascertained by only physician diagnosis yields similar prevalence rates for older Black and white adults and among older adults with different levels of education.
Chen and colleagues show that in the years following cognitive decline in older adults, only a small portion (15%) never receive a dementia diagnosis. However, Black and Hispanic adults, and people with low levels of education, are at higher risk of having a delayed or no dementia diagnosis. Both cognitive tests and a physician diagnosis have limitations, the researchers conclude, yet methodological advances and policy changes may be improving identification and diagnosis of dementia among different groups.
Intersectionality: Disparities Compound to Increase Negative Health Impacts
Mounting evidence shows that health disparities related to race/ethnicity, gender, and socioeconomic status interact, increasing health disadvantages. The health risk of compounded disparities is not the sum of each but a multiple of all.
For instance, older Black females experience especially poor health, Tyson H. Brown and colleagues show based on data from the nationally representative HRS.7 The researchers focused on self-reported health, a measure that previous studies show is more closely related to a person’s actual health status.
Brown and colleagues demonstrate that the effects of racial/ethnic, gender, and socioeconomic inequality on health interact to produce inequalities in health among women. They show that Black and Mexican American women have elevated risks of poor health above and beyond what would have been predicted by simply examining race/ethnicity or gender alone. Having higher levels of education—an advantage—is more strongly related to better health among white men and women than among their Black and Mexican American peers.
Being a Black woman is associated with increased risk of having hypertension (high blood pressure) beyond that related to being Black or female separately, a study by Liana J. Richardson and Brown based on HRS data shows.8 They also find that Black women experience elevated rates of hypertension at younger ages than do other racial or ethnic groups.
“We interpret racial/ethnic and gender inequalities, not as effects of race/ethnicity and gender per se, but rather as a result of relations of domination and subordination stemming from racism, sexism, and their consequences for class inequality,” Richardson and Brown write.
They emphasize the importance of taking gender into account when focusing on racial/ethnic disparities so interventions can target groups at highest risk. Policies and interventions should recognize that age, racial/ethnic, and gender inequalities operate together to increase hypertension risk, they argue.
- Mark D. Hayward et al., “The Importance of Improving Educational Attainment for Dementia Prevalence Trends from 2000 to 2014, Among Older Non-Hispanic Black and White Americans,” The Journals of Gerontology: Series B, Psychological Sciences and Social Sciences 75 (2021): https://doi.org/10.1093/geronb/gbab015.
- Mateo P. Farina et al., “Racial and Educational Disparities in Dementia and Dementia-Free Life Expectancy,” The Journals of Gerontology: Series B, Psychological Sciences and Social Sciences 75, no. 7 (2020): e105–e112, https://doi.org/10.1093/geronb/gbz046.
- Vicki A. Freedman et al., “Short-Term Changes in the Prevalence of Probable Dementia: An Analysis of the 2011–2015 National Health and Aging Trends Study,” The Journals of Gerontology: Series B, Psychological Sciences and Social Sciences 73 (2018): S48-S56, https://doi.org/10.1093/geronb/gbx144.
- Kenneth M. Langa, “Cognitive Aging, Dementia, and the Future of an Aging Population,” in Future Directions for the Demography of Aging: Proceedings of a Workshop (Washington, DC: National Academies Press, 2018), https://doi.org/10.17226/25064.
- Debra Umberson et al., “Death of a Child Prior to Midlife, Dementia Risk, and Racial Disparities,” The Journals of Gerontology: Series B, Psychological Sciences and Social Sciences 75, no. 9 (2020): 1983-95, https://doi.org/10.1093/geronb/gbz154.
- Yi Chen et al., “Analysis of Dementia in the US Population Using Medicare Claims: Insights From Linked Survey and Administrative Claims Data,” Alzheimer’s & Dementia 5, no. 1 (2019): 197-207, https://doi.org/10.1016/j.trci.2019.04.003.
- Tyson H. Brown et al., “Using Multiple-Hierarchy Stratification and Life Course Approaches to Understand Health Inequalities: The Intersecting Consequences of Race, Gender, SES, and Age,” Journal of Health and Social Behavior 57, no. 2 (2016): 200-22, https://doi.org/10.1177/0022146516645165.
- Liana J. Richardson and Tyson H. Brown, “(En)gendering Racial Disparities in Health Trajectories: A Life Course and Intersectional Analysis,” SSM—Population Health 2 (2016): 425-35, https://doi.org/10.1016/j.ssmph.2016.04.011.