Association between tooth loss and frailty among Chinese older adults: the mediating role of dietary diversity

BACKGROUND: This study aimed to examine the association between tooth loss and frailty among Chinese older adults and the mediating role of dietary diversity in this association. METHODS: Data from five waves of the Chinese Longitudinal Healthy Longevity Survey conducted between 2005 and 2018 were used. Path analyses were employed to assess both concurrent and cross-lagged relationships between tooth loss and frailty index while accounting for intrapersonal correlation. Furthermore, the mediation effect of dietary diversity was also examined. RESULTS: In concurrent models, severe tooth loss was associated with frailty after adjusting for demographic characteristics (odds ratio [OR] = 1.82, p < 0.001). The OR of frailty for severe tooth loss was only slightly decreased to 1.74 (p < 0.001) when dietary diversity was added to the model and to 1.64 (p < 0.001) when socioeconomic status, family support, and healthy lifestyles were further adjusted. In the cross-lag or longitudinal models, the ORs were mildly or moderately reduced to 1.29, 1.27, and 1.23, respectively, yet remained statistically significant (p < 0.001 or p < 0.01). The mediation analyses showed that dietary diversity had some small yet significant effects on the relationship between tooth loss and frailty in both concurrent and longitudinal settings. CONCLUSIONS: This study improves current knowledge regarding the impact of tooth loss on frailty among Chinese older adults. Future intervention strategies designed to improve healthy diets may have preventive effects against the risk of frailty among Chinese older adults with severe tooth loss. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12877-023-04355-6.