The natural sweetener xylitol is used in sugar-free chewing gums and toothpastes and it has been postulated that it may protect teeth from decaying. But a recent Cochrane review
casts doubt on this claim.
Philip Riley from the school of dentistry at the University of Manchester led an analysis of data from ten studies published between 1991 and 2014 involving 5,903 participants that looked at the effect of xylitol on teeth.
The reviewers found little or no good-quality evidence to prove xylitol has a protective effect against tooth decay. Evidence linking the use of xylitol-supplemented toothpaste with a 13% reduction in tooth decay in the permanent teeth of children was low quality. The reviewers call for randomised controlled trials to test the true effects of xylitol products on teeth.