Research Paper Volume 15, Issue 18 pp 9310—9340

Pathways explaining racial/ethnic and socio-economic disparities in dementia incidence: the UK Biobank study

May A. Beydoun1, , Hind A. Beydoun2, , Marie T. Fanelli-Kuczmarski1, , Jordan Weiss3, , Michael F. Georgescu1, , Osorio Meirelles1, , Donald M. Lyall4, , Michele K. Evans1, , Alan B. Zonderman1, ,

  • 1 Laboratory of Epidemiology and Population Sciences, National Institute on Aging, NIA/NIH/IRP, Baltimore, MD 21224, USA
  • 2 Department of Research Programs, Fort Belvoir Community Hospital, Fort Belvoir, VA 22060, USA
  • 3 Stanford Center on Longevity, Stanford University, Stanford, CA 94305, USA
  • 4 School of Health and Wellbeing, University of Glasgow, Glasgow, Scottland, UK

Received: May 8, 2023       Accepted: August 21, 2023       Published: September 25, 2023
How to Cite

Copyright: © 2023 Beydoun et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Background: Pathways explaining racial/ethnic disparities in dementia risk are under-evaluated.

Methods: We examine those disparities and their related pathways among UK Biobank study respondents (50–74 y, N = 323,483; 3.6% non-White minorities) using a series of Cox proportional hazards and generalized structural equations models (GSEM).

Results: After ≤15 years, 5,491 all-cause dementia cases were diagnosed. Racial minority status (RACE_ETHN, Non-White vs. White) increased dementia risk by 24% (HR = 1.24, 95% CI: 1.07–1.45, P = 0.005), an association attenuated by socio-economic status (SES), (HR = 1.12, 95% CI: 0.96–1.31). Total race-dementia effect was mediated through both SES and Life’s Essential 8 lifestyle sub-score (LE8LIFESTYLE), combining diet, smoking, physical activity, and sleep factors. SES was inversely related to dementia risk (HR = 0.69, 95% CI: 0.67, 0.72, P < 0.001). Pathways explaining excess dementia risk among racial minorities included ‘RACE_ETHN(−) → SES(−) → DEMENTIA’, ‘RACE_ETHN(−) → SES(−) → Poor cognitive performance, COGN(+) → DEMENTIA’ and ‘RACE_ETHN(−) → SES(+) → LE8LIFESTYLE(−) → DEMENTIA’.

Conclusions: Pending future interventions, lifestyle factors including diet, smoking, physical activity, and sleep are crucial for reducing racial and socio-economic disparities in dementia.


AD: Alzheimer’s Disease; AL: Allostatic Load; ALCOHOL: alcohol consumption, z-score; BMI: Body Mass Index; CI: Confidence Interval; COGN: Poor cognitive performance principal component variable (3 measured variables); DIET/NUTR: diet and nutritional biomarkers z-score variable (3 dietary quality measures and 4 nutritional biomarkers); DX: Diagnosis; GSEM: Generalized Structural Equations Modeling; HEALTH: Poor health-related factors as mean of z-scores for allostatic load, self-rated health, co-morbidity index and body mass index; HR: Hazard Ratio; IR: Incidence Rate; ICD-9: International Classification of Diseases, 9th revision; ICD-10: International Classification of Disease, 10th revision; LCL: Lower Confidence Limit; LIFESTYLE: Lifestyle-related factors composed of social support, physical activity, diet, nutritional biomarkers, smoking and alcohol consumption using means of z-scores for related measured variables; LOAD: Late-Onset Alzheimer’s Disease; N: number of participants; N’: number of observations; PA: Physical activity z-score variable (3 measured variables); RACE_ETHN: racial/ethnic contrast; SES: Socio-economic status mean of z-scores composed of income, education and Townsend deprivation index; SMOKING: smoking z-score variable; UCL: Upper Confidence Limit; UKB: UK Biobank.