Xylitol is a natural sweetener that can be found in everyday products including sugar-free chewing gum, toothpaste, gels, lozenges and sweets. Xylitol is already known to cause less damage to teeth than sugar. It has also been suggested that the addition of xylitol to products may help to prevent tooth decay by stopping the growth of decay-producing bacteria. However, according to new evidence published in the Cochrane Library, there is little high quality evidence that it is beneficial in the fight against tooth decay.
The authors gathered data from 5,903 participants in ten different studies. In most cases, the studies used such different methods that researchers could not combine the results. Based on information from 4,216 school children who took part in two Costa Rican studies, they found low-quality evidence that levels of decay were 13% lower in those who used a fluoride toothpaste containing xylitol for three years, compared to those who used a fluoride-only toothpaste. For other xylitol-containing products, such as syrup, lozenges and tablets, there was little or no evidence of any benefit.
The researchers stated that the evidence did not allow them to make any robust conclusions about the effects of xylitol, and they were unable to prove any benefit for preventing tooth decay. They were particularly surprised to see such a lack of evidence on xylitol-containing chewing gums.
Several of the studies included in the review did not report sufficient information on the side effects of xylitol, which can include bloating, diarrhoea and laxative effects. The researcher said that sugar-free gums, sweets, mints and other products are well known for their gastrointestinal effects and these should be clearly reported in future studies.