A new understanding of the relationship between sugars, dental caries and fluoride use: implications for limits on sugars consumption

Objective: To examine the quantitative relationship between sugar intake and the progressive development of dental caries. Design: A critical in-depth review of international studies was conducted. Methods included reassessing relevant studies from the most recent systematic review on the relationship between levels of sugars and dental caries. Reanalysis of dose-response relationships between dietary sugars and caries incidence in teeth with different levels of caries susceptibility in children was done using data from Japanese studies conducted by Takeuchi and co-workers. Setting: Global, with emphasis on marked differences in both national sugar intake and fluoride use and preferably where one factor such as sugar intake changed progressively without changes in other factors over a decade or more. Subjects: Children aged 6 years or more and adults. Results: Caries occurred in both resistant and susceptible teeth of children when sugar intakes were only 2-3 % of energy intake, provided that the teeth had been exposed to sugars for > 3 years. Despite increased enamel resistance after tooth eruption, there was a progressive linear increase in caries throughout life, explaining the higher rates of caries in adults than in children. Fluoride affects progression of caries development but there still is a pandemic prevalence of caries in populations worldwide. Conclusions: Previous analyses based on children have misled public health analyses on sugars. The recommendation that sugar intakes should be <= 10 % of energy intake is no longer acceptable. The much greater adult burden of dental caries highlights the need for very low sugar intakes throughout life, e. g. 2-3% of energy intake, whether or not fluoride intake is optimum.