Exploring taste hyposensitivity in Japanese senior high school students

Association between taste perception, nutrient intake, and mental health in young Japanese women

BACKGROUND/OBJECTIVES

Taste perception is influenced by both nutritional factors and psychological factors. This study was undertaken to measure the 4 basic taste perceptions, nutrient intake, and mental health, and to examine the factors that affect insensitive taste perception in young Japanese women.

SUBJECTS/METHODS

Young women in their late teens and twenties were enrolled as subjects. Taste perception was measured by applying the filter-paper disc method over areas of the chorda tympani nerve. Nutritional status was evaluated using brief, self-administered diet history questionnaires. The index of nutritional status was based on the 2015 Japanese dietary reference intakes. Mental health was assessed using the Japanese translation of the Profile of Mood States short version. This study was approved by the ethical committee at Osaka University.

RESULTS

The normal taste perception group (four basic tastes [sweet, salty, sour, and bitter] identified as normal taste perception) comprised 55.4% of the subjects, while the abnormal taste perception group (more than 1 abnormal taste perception was perceived, regardless of flavor) comprised 44.6% of the subjects. There were no significant differences in nutrient intake (except manganese) and mental health between the normal and abnormal taste perception groups. Subjects who took 5 mg to less than 7.1 mg zinc per day were at significantly decreased risk of insensitive taste perception compared to subjects who consumed less than 5 mg zinc per day [Regression coefficient 0.831, 95% confidence interval 0.694-0.996].

CONCLUSION

The present results suggest that insensitive taste perception could be associated with zinc deficiency in young women in their late teens and twenties.

Taste hyposensitivity in Japanese schoolchildren

Background

There is some research on taste disorder/hyposensitivity in special groups such as the elderly or patients presenting with specific taste problems, however few studies have been conducted among young populations. The objectives of this study were to estimate the prevalence of taste hyposensitivity and to investigate the relationship between taste hyposensitivity and oral health status in Japanese schoolchildren.

Methods

Subjects were 237 primary and 112 junior high school students in Saitama Prefecture, Japan. In total, 349 (boys: 181, girls: 168) students aged 6–15 years participated in the study. Oral examinations and whole-mouth taste tests using four tastes (sweet, salt, sour and bitter) solutions were conducted on the subjects. A subject who could not recognize the taste of the solution was defined as demonstrating hyposensitivity.

Results

Hyposensitivity was observed in 6.3% of all subjects for sweet-taste, 14.3% for salt-taste, 20.9% for sour-taste and 6.0% for bitter-taste. The prevalence of sweet, sour and bitter-taste hyposensitivity decreased as the subjects’ grade advanced. In contrast, the prevalence of salt-taste hyposensitivity increased in 7^th-9^th grade subjects. Furthermore, the prevalence of bitter-taste hyposensitivity was significantly higher in males than females among 1^st-3^rd graders.

Taste hyposensitivity had little association with oral health status, such as decayed teeth, filled teeth, dental plaque, gingival status and tongue coating.

Conclusions

In this study, taste hyposensitivity was observed in 6.0%-20.9% of the students. There was little association between taste hyposensitivity and oral health status. The current study implies that the factors affecting the taste hyposensitivity in children may different from those in the elderly. Therefore it is necessary to further investigate the causes of taste hyposensitivity among younger generation.