Systematic Review of the Effect on Caries of Sugars Intake: Ten-Year Update

An update of the systematic review of evidence on the association between amount of sugars intake and dental caries, as well as on the effect of restricting sugars intake to <10% and <5% energy (E) on caries, was conducted, almost 10 y since the review that informed the World Health Organization (WHO) Guideline on Sugars. The aim was to systematically review epidemiological data published from 2011 to 2020 on the amount of sugars consumption and levels of caries and to report the findings for adults and children. Data sources included MEDLINE, EMBASE, Cochrane Database, Cochrane Central Register of Controlled Trials, Latin American and Caribbean Health Sciences, China National Knowledge Infrastructure, Scopus, and Google Scholar. Eligible studies reported the amount of sugars and caries, measured as prevalence, incidence, or severity. The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Risk of bias was assessed using the Office of Health Assessment and Translation tool. Vote counting and harvest plots provided the basis for evidence synthesis. From 488 new papers identified, 23 studies were eligible: 4 cohort, 1 case-controlled, 12 cross-sectional, and 6 ecological. Eleven of 15 studies in children and 6 of 8 studies in adults reported at least 1 positive association between sugars and caries. Six of 7 studies in children and 4 of 4 studies in adults, with data enabling comparison of caries levels with sugars intakes >10%E and <10%E, showed lower caries when sugars intake was <10%E. Amalgamating with original studies yielded 64 of 78 studies showing at least 1 positive association, 20 of 78 a null association, and 3 of 78 a negative association between sugars and caries. GRADE profiles of new and original cohort data confirmed "moderate-quality" evidence that caries is lower when sugars intake is <10%E. Furthermore, new cohort data upgraded the quality of evidence (from "very low" to "low") for lower caries when free sugars are <5%E. The findings support and strengthen original evidence underpinning the WHO recommendations for sugars.