Association of eating alone with oral frailty among community-dwelling older adults in Japan

Background: Because the oral cavity plays an important role as the first digestive organ, thus, decreased oral function such as oral frailty may negatively affect the nutritional status of older adults. However, few studies have examined the relationship between oral frailty and dietary habits. Objective: This cross-sectional study aimed to investigate the relationship between oral functions and dietary habits in a general population of older adults. Methods: Participants were 722 older adults (mean age, 79.1 +/- 4.5 [standard deviation] years) who had participated in the Takashimadaira Study conducted in 2018, in Tokyo, Japan. Oral frailty among them was determined by a modified version of a well-known method originally proposed by other researchers. Dietary habits were evaluated based on two aspects: dietary variety and eating behavior (eating alone or together). The independent association between oral frailty and dietary habits was analyzed with an ordinal logistic regression model, controlling for important covariates. Results: Of the participants, 23.5 %, 57.2 % and 19.3 % were determined to have non-oral frailty, pre-oral frailty, and oral frailty, respectively. Eating alone (practiced by 36.0 % of the participants) was significantly associated with oral frailty status (adjusted odds ratio, 1.82 [95 % confidence interval, 1.14-2.90]) even after controlling for potential confounders including age, sex, body mass index, living arrangement, employment, chronic medical conditions, and depressive mood. Conclusions: We found a significant association between eating alone and oral frailty in a general population of Japanese older adults. Because of the strong association, further investigation of potential mechanisms is warranted.