Objective: Although tooth loss causes a decrease in masticatory ability, which may influence nutritional status, and impair an individual's general health including physical activity, little is known whether a decrease in chewing ability could result in deterioration in physical fitness in a very elderly population. Thus, the present study evaluated the relationship of chewing ability or teeth number with measures of physical fitness in a sample of 80-years-old in Japan.
Design: Cross-sectional survey.
Subjects and methods: A total of 1282 people who were 80-years old and resided in the Fukuoka Prefecture were approached. A total of 697 individuals (277 male, 420 female) agreed to participate.
Results: Chewing food number and teeth number were related positively with physical fitness measurements of hand grip strength, leg extensor strength, leg extensor power, stepping rate, and one-leg standing time. However, the significant relationship between the number of teeth and physical ability disappeared after adjustment for various confounders, using multiple regression analysis or logistic regression analysis. On the other hand, the relationship of chewing ability with physical fitness measurements of leg extensor strength, one-leg standing time, or isokinetic leg extensor power remained significant even after adjustment for these confounders.
Conclusion: There is a relationship between perceived chewing ability (number of foods considered chewable) and physical fitness in this 80-year-old population. Chewing ability may be an independent predictor of physical fitness, thus preventative dental care aimed at preserving chewing ability may be able to enhance activities of daily life and quality of life in very elderly individuals.