Association between habitual masticatory movements and cognitive function among community-dwelling older adults: A...

To examine the association between habitual masticatory movements and cognitive function in community-dwelling older adults.

Participants were recruited from a cohort study conducted in the Tamba-Sasayama area of Japan between June 2024 and November 2025. A total of 136 age- and sex-matched candidates were selected based on previous Mini-Mental State Examination (MMSE) scores: 68 with scores ≤27 and 68 with scores ≥28. Oral examinations, physical function tests, and questionnaire surveys were conducted. Masticatory movements were assessed using the total number of chewing cycles required to consume a rice ball while wearing bitescan^®. Participants with current MMSE scores ≤27 were classified as cognitively impaired, whereas those with scores ≥28 were classified as cognitively healthy. Logistic regression analysis was performed with cognitive status as the dependent variable and demographic, physical, and oral function variables as covariates.

Among the 111 participants included in the analysis (median age, 80 years; 42 male and 69 female), 37 were classified as cognitively impaired and 74 as cognitively healthy. The mean number of chewing cycles was lower in the cognitively impaired group than in the cognitively healthy group (227.3 vs. 272.3, P = 0.088). In a sensitivity analysis, fewer chewing cycles (odds ratio [OR] = 0.994, 95% confidence interval [CI]: 0.989-1.000, P = 0.039) and lower instrumental activities of daily living (OR = 0.692, 95% CI: 0.487-0.983, P = 0.040) were associated with cognitive impairment.

Fewer chewing cycles during eating may be associated with cognitive impairment in community-dwelling older adults.