(CBS) Chew on this. A new study suggests that sugar-free gum can damage teeth.
Does this mean that four out of five dentists are dopes?
For the study - published in the Oct. 7 issue of the British Dental Journal - researchers reviewed all the medical literature on sugar-free sweets, and found that sugar-free gums may contain acidic flavorings and preservatives. The researchers say those additives - common in fruit-flavored sugar-free gum - can cause dental erosion, an irreversible mineral loss that can cause structural damage to the teeth.
"The term sugar-free may generate false security because people may automatically believe that sugar-free products are safe on teeth," Dr. Sok-Ja Janket, an associate research professor at Boston University School of Dental Medicine, said in a written statement. "The public should be educated on the hidden risk of dental erosion due to acidic additives."
Many sugar-free gums contain xylitol, an FDA-approved sugar substitute. Studies have shown that xylitol reduces the risk of tooth decay. The European Union also approved xylitol as "tooth friendly," the authors said. In 2007, the American Dental Association even recommended sugar-free gum because chewing it generates more saliva, which helps wash away plaque and coats the teeth minerals thought to prevent cavities, CBS News reported.
The American Dental Association did not respond to CBS News' request for comment at press time.
What isn't tooth-friendly - according to these authors - is when xylitol is combined with the acidic flavor additives. And it's not just for gum - sugar-free sodas and hard candies also might contain these additives. The erosion risk increases the longer the acid stays on the teeth, according to Janket, so people that suck on a slow-melting sugar-free hard candy may cause a lot more harm than they bargained for.
"Not all sugar-free products are healthy," Dr. Janket told CBS News in an email. "Avoid sour, acidic flavors in sugar-free products."
So what should worried chewers do? For starters, you might want to cut back on candy - some sugar-free candies and beverages contain up to 50 percent of calories as their sugared counterparts. But even for those who can't kick candy, there's hope.
"It appears that there are healthy sugar-free products that do not cause dental erosion,"Janket told CBS News. "We think mint-chocolate chip or butterscotch flavors seem acceptable."
WebMD has more on tooth erosion.