Relationship between Oral Function and Food Preferences among Elderly Japanese

Abstract

Objective: Aging affects the sense of taste, and consequently food preferences change in the elderly. However, preferences might be influenced not only by oral sensory function but also by chewing and swallowing function. This study aimed to clarify the relationship between oral function and food preferences among elderly Japanese.

Materials and Methods: Forty patients (mean age, 74.2 years) of the dental hygiene clinic in Tokushima University Hospital were enrolled in the elderly group. Twenty-five university students (mean age, 21.4 years) were enrolled in the young group.

Food preferences were assessed using a questionnaire on favorite foods among 35 items, based on mastication score (MS). Chewing function was assessed using a xylitol gum-chewing test (Lotte Co., Ltd.) and MS. Swallowing function was assessed using number of saliva swallows in 30 seconds, water swallow test, maximum voluntary tongue pressure (MVTP) and subjective swallowing evaluation (SSE).

The Mann-Whitney U test, χ² test, Spearman’s rank correlation coefficient, and stepwise regression analysis were performed for statistical analyses using SPSS ver.21.

This study was conducted with the approval of the Ethics Committee of Tokushima University Hospital (Approval number: 1378).

Results and Discussion: The scores of the gum-chewing test, MS, number of saliva swallows in 30 seconds, MVTP and SSE of the elderly group were significantly lower than those of the young group. There was a significant correlation between RSST and food preference scores in the elderly group, but not in the young group. Moreover, there were significant correlations between SSE and food preference score, and also between the number of saliva swallows in 30 s and food preference scores in the elderly group with stepwise regression analysis in order to exclude confounding factors between age and oral function.

It is considered that the changes of swallowing function with aging affect food preferences among elderly Japanese.

Conclusion: Our results indicate that swallowing function influences food preferences among elderly Japanese.