Relationship between a gum-chewing routine and oral, physical, and cognitive functions of community-dwelling older adults: A Kashiwa cohort study.

AIM: As associations between oral function and general health have been reported in community-dwelling older adults, easily implementable preventive measures are urgently required. We focused on the health benefits of gum chewing, as no studies have been carried out on the impact of gum-chewing routines on the health of older adults. This cross-sectional study aimed to determine whether the gum-chewing routine is associated with oral, physical and cognitive functions in community-dwelling older adults. METHODS: This study included 1617 community-dwelling older participants in a health survey carried out in 2021. The gum-chewing routine and weekly chewing time were assessed using a self-administered questionnaire. The outcome measures, including actual measurements of oral function, physical function, cognitive function, dietary intake and lifestyle, were evaluated using self-administered questionnaires or health surveys. RESULTS: We analyzed 1474 (mean age 76.1 ± 5.8 years, 45% women) participants for whom all data were not missing, and 14% of them had a gum-chewing routine for more than 30 min weekly. Oral functions were significantly higher in older adults with a gum-chewing routine, and there were substantially fewer participants with oral frailty (adjusted odds ratio 0.581, 95% confidence interval 0.340-0.993). Additionally, cognitive and physical functions, including grip strength, were significantly higher in the gum-chewing routine group. CONCLUSIONS: Community-dwelling older adults with a gum-chewing routine have higher oral, physical and cognitive functions. These findings indicate that a gum-chewing routine might contribute to maintaining oral function and preventing frailty. Geriatr Gerontol Int 2024; 24: 68-74.

Oral frailty as a risk factor for mild cognitive impairment in community-dwelling older adults: Kashiwa study.

BACKGROUND: Oral frailty is defined as a slight decline in comprehensive oral function and can predict the onset of adverse health outcomes including morbidity in community-dwelling older adults. Previously, the number of remaining teeth and masticatory status had been suggested to be associated with cognitive decline. The effects of comprehensive oral condition on cognitive decline have not been adequately examined. In this study, we aimed to examine whether oral frailty is associated with new-onset mild cognitive impairment (MCI) among community-dwelling older adults. METHODS: Two thousand and forty-four participants of a longitudinal cohort study in Kashiwa City, Chiba Prefecture, without cognitive decline who participated in at least one follow-up survey, were included. New-onset MCI was assessed using the Mini-Mental State Examination (score < 27 defined as MCI). Oral frailty was evaluated based on six components including the number of remaining teeth, masticatory status, tongue pressure, oral motor skills, and subjective difficulties in eating and swallowing. "Oral non-frailty" was defined as good performance on all six measures, "oral pre-frailty" was defined as poor performance on one or two measures, and "oral frailty" was defined as poor performance on three or more measures. Statistical analysis was performed, mainly using a Cox proportional hazards model. RESULTS: Of the 1410 participants who did not fit the exclusion criteria (mean 72.4 ± 5.2 years; 49 % female), 19 % had new-onset MCI during the follow-up period. When comparing the status of oral frailty (non-frailty, oral pre-frailty, and oral frailty), the oral frailty group had a significantly higher hazard ratio for new-onset MCI than the other groups, even after adjusting for confounding factors. Among the six components, a decrease in the number of remaining teeth, low tongue pressure, and difficulty eating tough foods significantly correlated with new-onset MCI. Additionally, we found individuals with co-existing oral frailty and physical frailty to be associated with an increased risk of MCI. However, no significant increase in hazard ratio was observed in participants with either physical or oral frailty. CONCLUSIONS: The study findings suggest that oral frailty could predict the risk of new-onset MCI in community-dwelling older adults. Further, we found that oral frailty with physical frailty exacerbated this risk, implying the existence of direct or additive effects on cognitive dysfunction. Comprehensive oral health focusing on maintaining eating function can be a strategy to prevent MCI and delay dementia in community-dwelling older adults.