A sugar averts some ear infections.

How sweet it is! A natural sweetener called birch sugar helps to prevent some ear infections when given to young children, Finnish researchers report in the October Pediatrics. In the United States, gum made with birch sugar, also called Xylitol, is mainly sold in health food stores. It is more widely available in Europe.

Preschoolers receiving 8 to 10 grams of birch sugar five times each day--in either lozenges or pieces of gum--came, down with fewer middle ear infections over 3 months than playmates who daily received gum sweetened with sucrose and containing only a trace of birch sugar, says study coauthor Matti K. Uhari, a pediatrician at the University of Oulu in Finland.

Among 178 preschoolers given the sucrose-based chewing gum, 49 children were diagnosed with a total of 72 ear infections. Among 179 getting birch sugar gum, 29 children had 44 ear infections. Of 176 children receiving birch sugar lozenges, 39 came down with 52 infections.

Five-a-day doses of birch sugar given as a syrup proved less effective in preventing ear infections, trot a distinction still emerged between birch sugar syrup and sucrose syrup. Of 165 children who received a sucrose syrup, 68 contracted 114 infections, whereas 46 of 159 children getting birch sugar syrup came down with 69 infections.

Even though it is a sweetener, birch sugar was shown to prevent tooth decay in earlier tests. So the researchers included 0.5 gram of birch sugar per day in the doses of sucrose syrup or gum to offset any tooth decay the sucrose might cause.

Laboratory experiments have shown that birch sugar inhibits growth of Streptococcus mutans, a bacterium that causes dental caries. Based on this, Uhari and his colleagues earlier had tested birch sugar against Streptococcus pneumoniae, a common cause of ear infections. They reported in 1995 that the sweetener inhibited this bacterium's growth in laboratory tests. The new work is the first large study to gauge birch sugar's effectiveness against the microbe in children.

S. pneumoniae latches onto cells in mucus, apparently riding this fluid up from the mouth and throat via the eustachian tubes to the ears, where it can cause an infection, Uhari says. Birch sugar seems to prevent this attachment some of the time, limiting the disease, he says.

If indeed that is the bacterium's mechanism, Uhari says, the microbe would "have no reason to develop resistance" to birch sugar, since the sweetener isn't killing it. Uhari and study coauthor Tero Kontiokari hold a U.S. patent on the use of Xylitol as a treatment for respiratory infections.