Relationship Between Dietary Sugar Intake and Dental Caries Among Japanese Preschool Children with Relatively Low Sugar Intake (Japan Nursery School SHOKUIKU Study): A Nationwide Cross-Sectional Study

摘要

Objectives The WHO has recently proposed to halve the recommendation for free sugar intake from 10 to 5 % of energy intake to reduce the incidence of diseases such as obesity and dental caries. The Japanese population is suitable to confirm the appropriateness of this proposal, because dietary sugar intake in Japan is exceptionally low among developed countries. We sought to establish a method to estimate dietary sugar intake in Japan and to examine the relationship between sugar and the number of dental caries using data obtained from the Japan Nursery School SHO-KUIKU study. Methods Dietary intake during the preceding month and the number of caries was examined in children aged 5-6 years using a brief-type self-administered diet history questionnaire for Japanese preschool children completed by their guardians and another questionnaire on lifestyle. Multivariate Poisson regression models were used for the analysis. Results When subjects were ranked into quintiles by the proportion of energy from free sugar, those in higher quintiles had more caries than those in the lowest quintile. On close analysis, the number of caries among children with a relatively small proportion of energy intake from free sugar (3.18-3.77 %) was not significantly different from that in the lowest group (0.95-3.17 %). Conclusions The recent proposition of WHO might be valid, because the adverse effect of relatively small proportion (approximately less than 5 %) of energy intake from free sugar on caries was not detected among the subjects in this study. However, more study will be necessary to reach a conclusion.