The Dementia Epidemic Among Older Black Americans

Posted on November 17, 2022

Co-authored by

Mark D. Hayward, Ph.D.
University of Texas at Austin

Mateo P. Farina, Ph.D.
University of Southern California

November is Alzheimer’s Awareness month. While it is a time to recognize the importance of supporting persons living with dementia, it is also a time to acknowledge the glaring disparities in dementia in our country. One such disparity is the epidemic levels of dementia among older Black Americans compared to White Americans.

The prevalence of dementia among Black Americans aged 65 years and older is about 2.5 times that for White Americans of the same age. In 2012, for example, a nationally representative study reported that 19.3% of older Black people had dementia compared to 7.4% of older White people¹. These differences are starker at older ages. For Black persons aged 75 years and older, the prevalence of dementia is 31%, compared to 9% for White persons of that age². Research reporting race differences in dementia onset—that is, new cases of dementia—document a similar race gap: Black people have about a 2.7 times greater risk of onset compared to White people³. These numbers translate into an extraordinary and disproportionate burden for Black individuals, their families, and their communities. This burden is often compounded by older Black Americans having fewer personal, social, economic, clinical, and community resources compared to White Americans. Moreover, the COVID-19 pandemic has increased these inequities, making care more difficult to obtain and placing a greater burden on familial caregivers.

The race disparity in dementia prevalence and incidence is largely reflective of the differences in exposures that Black Americans and White Americans experience throughout their lives, and not innate biological differences (e.g., genetic differences). For example, recent studies have documented a decline in both Black people and White people living with dementia from 2000-2014². The reason for the declining trend was unclear. Several hypotheses have been suggested: education improvements across birth cohorts, better control of hypertension, positive health behaviors, and improved childhood conditions. The evidence for this period points to a straightforward explanation. The downward trend in dementia prevalence for both Black people and White people since 2000 has been driven by increased educational attainment—shown by research to be one of the major risk factors contributing to the Black-White disparity—and is, largely, unrelated to changes in other major risk factors. This shows that improvements in education, and not medical interventions, had far-reaching benefits for dementia trends, although it is clear that the persistence of the race gap over time likely reflects Black individuals’ continued challenges in obtaining greater levels of education. This finding also provides additional evidence that improvements in social risk factors in early life can dramatically move the needle and reduce the burden of dementia decades later in the older population.

There is little doubt that cognitive health disparities defined by both race and education are enormous, and that highly educated White people and less educated Black people anchor the tail ends of the disparity. For example, highly educated 65-year-old White people can expect to live free of dementia for more than 17 years—an expectancy even greater than the total life expectancy for less educated Black people⁴. Less educated 65-year-old Black people, on the other hand, can only expect 10.59 years of life without dementia. The 7-year difference in life expectancy without dementia shows how stark these cognitive health inequalities can be. This difference is even more striking when considering the educational composition of the race groups; more than 50% of older Black individuals do not have a high school diploma, while about 38% of older White individuals have more than a high school education.

How, then, can we explain the higher rates of dementia among older Black people compared to White people? Addressing this problem is not straightforward. The lives of many older Black people differed in fundamental ways from the lives of older White people. About 80% of older Black Americans were born in the pre-1964 Jim Crow South, although many now live elsewhere as older adults. Growing up in the Jim Crow South not only meant dramatically different childhoods for Black Americans compared to White Americans due to curtailed economic, political, and social rights, but also because of living with the threat of violence. These childhood exposures may have had developmental consequences through stressors and limited opportunities, which reverberate decades later and place older Black Americans at greater risk of dementia. Research clearly documents that early life in a Southern context is associated with poor cognitive health. This association remains after controlling for educational attainment and adult risk factors. Understanding how and why a Southern context in childhood may be associated with poor cognitive health is essential to understand today’s disparities in cognitive health. What the future holds is unclear, yet it is clear that the racial divide in dementia will almost certainly reflect future disparities in resources, risks and opportunities.

References

1. Chen, C. and J.M. Zissimopoulos, Racial and ethnic differences in trends in dementia prevalence and risk factors in the United States. Alzheimer’s & dementia (New York, N. Y.), 2018. 4: p. 510-520.
2. Hayward, M.D., 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, 2021.
3. Zhang, Z., M.D. Hayward, and Y.-L. Yu, Life Course Pathways to Racial Disparities in Cognitive Impairment among Older Americans. Journal of Health and Social Behavior, 2016. 57(2): p. 184-199.
4. Farina, M.P., et al., Racial and Educational Disparities in Dementia and Dementia-Free Life Expectancy. The Journals of Gerontology: Series B, 2020. 75: p. e105-e112. PMC7530490.