Association Between Chewing Status and Fatty Liver in Japanese People Aged ≥ 50 Years: A Cohort Study

Background/Objectives: In this longitudinal study, the relationship between chewing status and fatty liver was examined in 3,775 people aged ≥ 50 years who underwent medical checkups at Junpukai Health Maintenance Center in Okayama, Japan. Methods: Participants without fatty liver at a baseline survey in 2018 were followed until 2022. Chewing status was assessed by self-administered questionnaire. The presence or absence of fatty liver was ascertained from the medical records of Junpukai Health Maintenance Center. Results: A total of 541 participants (14%) were diagnosed as having poor chewing status at baseline. Furthermore, 318 (8%) participants were newly diagnosed with fatty liver at follow-up. Multivariate logistic regression analyses showed that the presence or absence of fatty liver was associated with sex (male; odds ratio [OR], 1.830; 95% confidence interval [CI], 1.414-2.368), age (OR, 0.969; 95% CI, 0.948-0.991), body mass index (≥25.0 kg/m2; OR, 1.975; 95% CI, 1.510-2.585), diastolic blood pressure (OR, 1.017; 95% CI, 1.002-1.032), and chewing status (poor; OR, 1.475; 95% CI, 1.090-1.996) at baseline. Conclusions: The results indicate that poor chewing status was associated with fatty liver development after 4 years. Maintaining good chewing status may prevent future unhealthy fat accumulation in the liver.