At first glance, a claim that a sweetener derived from the bark of birch trees can prevent cavity formation might seem farfetched. It can’t be true, some might reason. Sugar causes cavities.
Not only are they wrong: The sweet compound from birch trees called xylitol does ward off cavities. But they are wrong twice, as it does so by blocking acid-producing bacteria in the mouth – the real cause of cavities, not sugar.
For an installment in our Fad or Fact? series, we spoke with Casey Rhines, DDS, clinical assistant professor in the Department of Restorative Dentistry at the University of Colorado School of Dental Medicine, to learn more about the buzz around xylitol, a sugar alcohol found in a growing number of products, including toothpastes, gummy bears, mouthwashes and mints.
The interview has been condensed and edited for clarity.