A natural sugar found in plums, strawberries, and raspberries, xylitol is used as a sweetener in some "sugarless" gums and candies. Not only does xylitol replace sugars that can lead to tooth decay, it also appears to help prevent cavities by inhibiting the growth of bacteria that cause cavities, such as Streptococcus mutans . 1 Xylitol also inhibits the growth of a related species, Streptococcus pneumoniae , which is a cause of ear infections . 2

Gums, toothpaste, and candy containing high levels of xylitol are beginning to become available in the United States.

What Is Xylitol Used for Today?

Many studies, including several under the auspices of the World Health Organization, have evaluated xylitol gums, toothpastes, and candies for preventing dental cavities, with good results. 3-9 In all of these studies, xylitol users developed fewer cavities than those receiving either placebo or no treatment.

Xylitol is thought to prevent cavities by inhibiting the growth of the Streptococcus mutans bacteria. 10 Since a related bacteria, Streptococcus pneumoniae , can cause ear infections, xylitol has been investigated as a preventive treatment for middle ear infections , with some success. 11-13

In addition, preliminary evidence suggests that use of xylitol may offer some protection against periodontal disease (gum disease). 6

What Is the Scientific Evidence for Xylitol?

Preventing Cavities

Double-blind, placebo-controlled studies enrolling a total of almost 4,000 people, mostly children, have found that xylitol gum, candy, or toothpaste can help prevent cavities . 14-19 One study also suggested that gummi bears may be an effective alternative method of administering xylitol to children. 29

A double-blind, placebo-controlled study of 1,677 children compared a standard fluoride toothpaste with a similar toothpaste that also contained 10% xylitol. 21 Over the 3-year study period, children given the xylitol-enriched toothpaste developed significantly fewer cavities than those in the fluoride-only group.

In another trial, a 40-month, double-blind study of 1,277 children, researchers studied gum products containing various concentrations of xylitol and/or sorbitol. 20 Participants were divided into nine groups: xylitol gum in four different concentrations, two forms of xylitol/sorbitol gum, sorbitol-only gum, sucrose (ordinary sugar) gum, or no gum.

The gum with the highest xylitol concentration proved most effective at reducing cavities. However, children in every one of the xylitol and/or sorbitol gum groups showed significant reductions in cavities as compared to the sugar gum or no-gum groups.

Another series of studies suggests that children acquire cavity-causing bacteria from their mothers; regular use of xylitol by a mother of a newborn child may provide some protection to the child, as well. 26-28

Ear Infections

One large double-blind, placebo-controlled trial of 857 children investigated how well xylitol (in chewing gum, syrup, and lozenges) could prevent ear infections . 24 The gum was most effective, reducing the risk of developing ear infections by a full 40%. Xylitol syrup was also effective, but less so. The lozenges weren't effective; researchers speculated that children got tired of sucking on the large candies and didn't get the proper dose of xylitol. (In addition, the children were able to distinguish between the xylitol and placebo lozenges by taste, making that portion of the study single-blind .)

Similarly positive results had been seen in an earlier double-blind study by the same researchers, evaluating about 300 children. 25

However, these studies were of short duration and did not test the long-term effect of xylitol in young children and infants, who are most at risk of contracting ear infections.


In the studies described above, dosages for cavity prevention ranged from 4.3 to 10 g per day. The doses were divided throughout the day, usually after meals. For ear infections, children given xylitol-sweetened gum received 8.4 g of xylitol daily, also in divided doses. Those who took syrup received 10 g daily.

Safety Issues

Xylitol is believed to be safe, but doses higher than 30 g per day can cause stomach discomfort and possibly diarrhea. In studies, children taking xylitol syrup tended to have more such side effects than those using other forms, possibly because it reached the stomach in a more concentrated dose.