Sugars and Dental Caries: Evidence for Setting a Recommended Threshold for Intake

Dental caries affects <= 80% of the world's population with almost a quarter of US adults having untreated caries. Dental caries is costly to health care and negatively affects well-being. Dietary free sugars are the most important risk factor for dental caries. The WHO has issued guidelines that recommend intake of free sugars should provide <= 10% of energy intake and suggest further reductions to <5% of energy to protect dental health throughout life. These recommendations were informed by a systematic review of the evidence pertaining to amount of sugars and dental caries risk, which showed evidence of moderate quality from cohort studies that limiting free sugars to <= 10% of energy reduced, but did not eliminate, dental caries. Even low levels of dental caries in children are of concern because caries is a lifelong progressive and cumulative disease. The systematic review therefore explored if there were further benefits to dental health if the intake of free sugars was limited to <5% of energy. Available data were from ecologic studies and, although classified as being of low quality, showed lower dental caries when free sugar intake was <5% of energy compared with when it was >5% but <= 10% of energy. The WHO recommendations are intended for use by policy makers as a benchmark when assessing intake of sugars by populations and as a driving force for policy change. Multiple strategies encompassing both upstream and downstream preventive approaches are now required to translate the recommendations into policy and practice.