Objectives: This study aimed to determine the relationship between objective chewing ability and the nutritional status of Japanese community-dwelling elders. Design: A cross-sectional study. Participants: A total of 509 community-dwelling elders living in the Tokyo metropolitan area participated in a comprehensive survey conducted in October 2013. Measurements: The basic characteristics were sex, age, and body mass index. Undernutrition was examined through serum albumin levels. Chewing ability was examined through color-changeable xylitol gum by evaluating the color changes in chewing gum. Nutritional intake was examined using the semi-quantitative food frequency questionnaire. Results: In the poor chewing ability group, all nutrient intake levels were significantly low, except for carbohydrates, and intake levels for all food groups were significantly low, except for cereals, confectionery, sugars, seasonings, and spices. Additionally, after adjusting for covariates for sex, age, Tokyo Metropolitan Institute of Gerontology-Index of Competence (TMIG-IC) score, Mini-Mental State Examination (MMSE) score, body mass index (BMI), stroke, number of functional teeth, energy intake, and protein intake, chewing ability was found to be significantly associated with undernutrition. Conclusion: We concluded that chewing ability was closely associated with nutrient and different food groups’ intake, as well as undernutrition, among Japanese community-dwelling elders. Thus, to ensure comprehensive nutritional management, nutritionists and dentists should collaborate when treating the same patients.

One prominent factor associated with malnutrition is poor appetite. In Japan, the number of older adults living alone has increased annually. Those living alone tended to eat alone, which may lead to poor appetite. This study aimed to investigate the association between eating alone and poor appetite using an index called the Simplified Nutritional Appetite Questionnaire (SNAQ). We surveyed 818 people aged 70 and over in Takashimadaira, Itabashi-ku, Tokyo, Japan, in 2016. Comparisons were made between two groups, a poor appetite group (n = 295) and a good appetite group (n = 523), and results indicate that the poor appetite group had a higher rate of eating alone than the good appetite group (38.0% vs. 20. 1%: p < 0.001). Multivariable logistic regression (OR; 95%CI) was performed and poor appetite was significantly associated with the Geriatric Depression Scale (GDS) score (1.707; 1.200–2.427), the number of medications (1.061; 1.007–1.118), JST score (0.894; 0.841–0.950), the indication of “very healthy” on a self-rated health scale (0.343; 0.152–0.774), and reports of eating alone (1.751; 1.130–2.712). Our results suggest that eating alone is associated with a poor appetite.

The association between dietary diversity and frailty remains unknown in older people. We evaluated whether a limited dietary variety is associated with frailty in older adults with diabetes mellitus (DM). This cross-sectional investigation included 1357 adults (median age: 77 years, women: 61.3%). DM was determined by self-reporting, the Dietary Variety Score (DVS) was used to evaluate dietary variety, and the revised Japanese version of the Cardiovascular Health Study criteria evaluated frailty. Participants were divided into 4 groups: no DM/high DVS (non-DMHV), no DM/low DVS (non-DMLV), DM/high DVS (DMHV), and DM/low DVS (DMLV). The prevalence of frailty in each group was 3.6%, 6.7%, 6.7%, and 12.2%. After adjusting for covariates, logistic regression analysis revealed the highest odds ratio (OR) of frailty in the DMLV (non-DMLV, OR = 2.18 (95% confidence interval (CI): 1.25–3.83); DMHV, OR = 1.87 (95% CI: 0.63–5.52); DML, OR = 5.03 (95% CI: 2.05–12.35)). Another logistic regression analysis revealed that a low DVS and DM were independently associated with frailty. Both a low dietary variety and DM were independently related to frailty in older people and the combination increased the prevalence of frailty. These findings suggest that high dietary variety could be important for the prevention of frailty in people with DM.

A limited number of longitudinal studies have explored factors contributing to decreases in tongue pressure (TP). This longitudinal study aimed to clarify the factors affecting TP decline among community-dwelling older adults. We followed the Takashimadaira Study participants with a baseline TP ≥ 30 kPa for 2 years. A TP of <30 kPa at follow-up was defined as TP decline. We used Poisson regression with robust standard errors to explore the factors related to TP decline. The studied baseline variables were dental status, sociodemographic characteristics, health behaviors, appetite, medical conditions, physical function, cognitive status, and anthropometric and body composition characteristics. Inverse probability weighting (IPW) was used to adjust for selection bias. Overall, 357 individuals (159 men and 198 women) with a mean (standard deviation) age of 75.9 (4.1) years were included in the analyses. Of these, 59 study participants (16.5%) exhibited TP decline. After adjusting for baseline TP and applying IPW, poor appetite (incident rate ratio [95% confidence interval] = 1.58 [1.01–2.48]), low skeletal muscle mass index (1.66 [1.02–2.70]), and cognitive impairment (1.93 [1.12–3.33]) were associated with TP decline. In conclusion, we demonstrated that baseline appetite, body composition, and cognitive status could predict future TP decline among community-dwelling older adults.