Free Sugars Consumption around Bedtime and Dental Caries in Children: A Systematic Review

This systematic review aimed to assess the association between food and drink consumption around bedtime-specifically, food and drinks containing free sugars-and the risk of dental caries in children. Five electronic databases were searched (PubMed, Ovid Medline, EMBASE, Web of Science, and Scopus) to identify studies that investigated any relationship between food and drink around bedtime and dental caries in 3- to 16-y-old children. The Agency for Healthcare Research and Quality domain guidelines were used to assess the quality of the individual studies, while GRADE guidelines assessed the quality of studies based on the body of evidence. From 1,270 retrieved titles, 777 remained after removal of duplicates. Of these, 72 were reviewed in full. Eighteen studies fulfilled the inclusion criteria and were included in the analysis: 13 cross-sectional, 4 cohort, and 1 case-control. Studies were categorized into 3 age groups: 3- to 5-y-old, 6- to 11-y-old, and 12- to 16-y-old children. Based on the Agency for Healthcare Research and Quality criteria, 6 of the 18 studies were rated as providing good-quality evidence; 8 were rated as fair; and 4 were categorized as being of poor quality. It was not possible to conduct a meta-analysis, because of the considerable variations in the type of bedtime exposure and outcome measures. The studies showed a consistent positive association across the 3 age groups, with all 7 studies on preschool children reporting significant positive associations. However, the quality of the body of evidence pertaining to the consumption of food and drinks at bedtime (specifically, food and drinks containing free sugars) and risk of caries was rated as "very low." The results suggest that restricting free sugars before and at bedtime may reduce the risk of caries, but studies with improved design are needed to confirm this. Knowledge Transfer Statement: This is the first systematic review of the evidence assessing the association between caries risk in children and the consumption of food or drinks at bedtime-specifically, foods and drinks containing free sugars. Although the data showed a consistent positive association, the quality of evidence was very low. This means that the current recommendation to restrict food and drinks containing free sugars before bedtime in children, while based on a sound physiologic premise, is supported only by very low-quality published evidence as measured by GRADE guidelines.