Oral Health Status, Knowledge, Hygiene Behavior and Cognitive Function Among Older Adults in Shanghai, China

Cognitive impairment is a growing concern in rapidly aging societies, including China, and oral health has been proposed as a modifiable correlate of cognitive aging; however, few studies compare distinct oral health domains within the same older population or identify the subgroups in which associations are strongest. We analyzed data from 1707 community-dwelling adults aged 55+ in the 2022 Lifelong Learning and Productive Aging Survey of Shanghai (LEAP-SH) study. Cognitive problems were measured with the Ascertain Dementia 8 (AD8) total score (0–8; higher = worse). Self-reported oral health, oral health knowledge, and oral hygiene behavior were each standardized and entered in separate models adjusted for sociodemographic and health covariates; interaction models tested effect modification by six sociodemographic moderators. All three domains were associated with lower AD8 scores, most strongly oral health status (β = −0.26; p < 0.001), followed by oral health knowledge (β = −0.14; p = 0.004) and oral hygiene behavior (β = −0.10; p = 0.036). Associations were broadly consistent across subgroups; only two interactions, both involving knowledge, were nominally significant, and neither survived correction for multiple comparisons. Oral health may be a modifiable correlate of cognitive aging, although the cross-sectional design precludes causal inference.