20 July 2023

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Edentulism predicts cognitive decline

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This longitudinal cohort study examines if cognitive decline varies by birth cohort, adjusting for covariates, and edentulism and nonuse of dental care predict a 10-year cognitive decline.

Researchers used the University of Michigan Health and Retirement Study which features a representative sample of U.S. adults over age 50.

Eligibility criteria included having cognitive interview data available and responding to the question, “Have you lost all of your upper and lower natural permanent teeth?” at two or more time points between 2006 and 2018.

The team assessed use of dental care in the past two years. Linear mixed models for repeated measures estimated the trajectories of mean cognition over time for the birth cohorts, adjusted for baseline cognition, dentition status, dental care use and covariates (demographic characteristics, health behaviors, and medical conditions).

Cohort-by-time interaction terms were included to assess if cognitive decline varied by birth cohort. The research team looked at a 10-year change in cognition status (measured by HRS Cogtot27) — categorized as dementia (<7); cognitive impairment, not demented (7-11) 7≤Cogtot27<12; and normal (≥12) — was also investigated according to birth cohort, dentition status, and dental care use.

Mean (SD) baseline age was 63.4 (10.1) y (n = 22,728).

Older birth cohorts had greater cognitive decline than younger cohorts. Linear mixed-model estimates and 95% confidence intervals for protective factors for cognitive decline included higher baseline cognition (HRS Cogtot27) (0.49; 0.48–0.50), use of dental care in the past 2 y (0.17; 0.10–0.23), and covariates such as greater household wealth and being married.

Risk increased with being edentulous (−0.42; −0.56 to −0.28), having a history of stroke or diabetes, less education, being a Medicaid recipient, current smoker, experiencing loneliness and poor or fair self-rated health.

Researchers concluded that edentulism and irregular dental care are among important predictors of cognitive decline. Tooth retention and regular dental care throughout life are important for maintaining oral and cognitive health.

Jones JA, Moss K, Finlayson TL, Preisser JS, Weintraub JA. "Edentulism Predicts Cognitive Decline in the US Health and Retirement Cohort Study." Journal of Dental Research. 2023;102(8):863-870. doi:10.1177/00220345231167805.