Dietary fiber intake and tooth retention among older Korean adults: Analysis of the Korea national health and nutrition examination survey (KNHANES)

Abstract

Objectives

Tooth loss in older adults adversely affects mastication, nutritional status, and quality of life. This study investigated the association between nutrient intake, particularly dietary fiber, and the number of remaining natural teeth among older Korean adults.

Basic research design

A cross-sectional analysis using national survey data.

Clinical setting

The 2022 Korea National Health and Nutrition Examination Survey (KNHANES).

Participants

A total of 1347 adults aged 65 years or older who completed both oral health examinations and 24-h dietary recalls.

Main outcome measures

Participants were categorized into 4 groups by number of remaining natural teeth (0, 1–19, 20–27, and 28). Complex sample-weighted multinomial logistic regression was performed.

Results

Higher dietary fiber intake was significantly associated with greater tooth retention after adjusting for sociodemographic, behavioral, and clinical factors. ORs for dietary fiber were 1.048 (95% CI: 1.012–1.086, p = .009), 1.063 (95% CI: 1.026–1.101, p < .001), and 1.059 (95% CI: 1.019–1.102, p = .004) for the 1–19, 20–27, and 28 teeth groups, respectively.

Conclusions

Higher dietary fiber intake was significantly associated with having more remaining natural teeth in older Korean adults. Each 5 g increment was associated with approximately 36% higher odds of having 20–27 teeth (OR ≈ 1.36), and each 10 g increment with an approximately 84% higher odds (OR ≈ 1.84). Given the cross-sectional design, these reflect associations rather than causal effects, and the possibility of reverse causation cannot be excluded. Fiber-focused dietary counseling may support preventive oral healthcare in older adults.