A primary sugar alcohol, xylitol is traditionally used as a sweetening agent. Although recent decades have seen an expansion in commercial manufacturing of this chemical, xylitol occurs naturally in low concentrations in some fruits and vegetables. Xylitol was discovered in the late 19th century in Europe. It was heralded as a sweetening agent for diabetics because its low caloric content would have less of an effect on insulin levels.
In sweetening power, xylitol is roughly equivalent to table sugar or sucrose, with one-third fewer calories.1 Regular table sugar has 3.87 kcal/g, and xylitol has 2.4 kcal/g.1 This is in contrast to other nonsugar sweetening agents that are noncaloric but chemically sensed by the brain and pancreas as much sweeter than standard sucrose.
The reduction in insulin stimulation is explained by xylitol’s extremely low glycemic index score of 7.2 Using glucose as the standard of 100, glycemic indices are assigned to foods based on the amount of insulin secreted per unit of substance ingested. One possible explanation of xylitol’s low score is that it is absorbed much more slowly than sucrose, resulting in a flatter postconsumption insulin response.
Xylitol’s initial use in controlling diabetes was quickly outpaced by the discovery of its action on reduction of dental caries. Xylitol has shown an antiplaque action that is due, in part, to its antimicrobial effect on the bacteria Mutans streptococci, which is the main protagonist of the caries-forming process.3
Xylitol blocks this bacterial proliferation by disrupting intracellular energy production, which eventually leads to cell death. Xylitol also has been found to impede caries formation by increasing salivary flow and pH, both of which are associated with reduced plaque formation, gingival inflammation, and enamel erosion. Due to the accumulating evidence on its safety and efficacy in preventing dental decay, xylitol has been approved by the American Academy of Pediatric Dentistry.4
Several decades of research support the daily use of xylitol based on its prevention of tooth enamel decay and process of remineralization of early caries.5 Most of the evidence for xylitol is based on trials with children and adolescents, rather than adults, and xylitol chewing gum, rather than lozenges or rinses. The question of method of delivery was addressed in one trial of 700 adults that found xylitol lozenges showed no significant reduction of dental caries compared with placebo.6