TUESDAY, July 8 (HealthDay News) -- A new sweet treat that actually prevents children's cavities should please children and their parents, researchers say.

The tasty syrup, which contains the sugar substitute xylitol, prevented early decay in infants' teeth and may play a role in protecting permanent teeth, says a team from the United States and the Marshall Islands, in the South Pacific.

Xylitol has long been approved by the U.S. Food and Drug Administration and is already found in food products such as chewing gum.

The compound protects children's teeth by reducing the number of oral bacteria that cause decay, explained study author Dr. Peter Milgrom, a professor of dental public health sciences at the University of Washington, Seattle.

"I kind of look at tooth decay as a kind of malnutrition," he added. A diet high in sugar promotes the bacteria that take in sugars, metabolize them, and produce the lactic acid that creates tooth decay, the researcher said.

The study involved 102 children from the Marshall Islands, ranging from 6 to 15 months of age. The researchers picked these islands as the study site, because childhood tooth decay occurs there at rates that are nearly triple that seen among kids on the mainland.

According to the researchers, 76 percent of the children whose caretaker applied the xylitol-laden syrup to their teeth three times a day were free of cavities a year later.

That compares to 48 percent of the children who did not receive daily xylitol applications.

Milgrom was expected to present the results this week at the annual meeting of the International Association for Dental Research in Toronto.

"It's a real problem that we've got all this dental disease in kids, and we really don't have all the tools we need to battle it," he said. "Of course, we knew that xylitol had these benefits for teeth from other studies that have been done, but they had never been done in small children. So, we sort of put two and two together," he added.

The bacteria, which are the "bad actors" here, can't metabolize sugars from xylitol, and so they die off, Milgrom explained. Only the so-called "good" bacteria that do not create decay and can tolerate being around xylitol live, he said.

Preventing early tooth decay is important to children's overall health in a number of ways, Milgrom added. He said that children with early decay tend to be underweight, often fail to thrive, and don't eat or sleep well, which affects their performance in preschool.

Early tooth decay also is a problem among many children in the United States, according to Dr. Paul Casamassimo, a professor of pediatric dentistry at Ohio State University and a spokesman for the American Academy of Pediatric Dentistry.

For example, in Ohio, about half of five-year-olds have some tooth decay, he said. That number tends to be higher in minority communities because of poor diets and lack of access to dentistry.

Decay in baby teeth is a "gateway disease that leads to decay in permanent teeth," Casamassimo added. "It's probably related to the fact these people have these bacterial factors in their mouths that continue on."

The study, which was co-authored by researchers from the Marshall Islands Ministry of Health, was funded by the U.S. National Institute of Dental and Craniofacial Research and the HRSA Maternal and Child Health Bureau. Milgrom said none of the researchers have any financial ties to manufacturers of xylitol.

There's more on keeping kids' teeth healthy at the American Academy of Pediatric Dentistry.