Stop fluoridation now: new research on fluoride's brain and thyroid toxicity

Townsend Letter for Doctors and Patients, April, 2005 by Gary Null, Martin Feldman

Xylitol is a sugar alcohol found in certain forest materials (such as birch and beech hardwoods) and foods (such as berries, plums, mushroom and lettuce). It is also produced by the body from food sources. Manufacturers use xylitol not only to replace sugars in foods (it has long been used as a sugar substitute in the diabetic diet) but also to develop xylitolcontaining products for dental use. (61, 62) The latter include products such as xylitol chewing gums, lozenges, candies, and mouthrinses that deliver the anticariogenic substance directly to the mouth.

An explanation of xylitol's mechanisms of action in reducing dental decay, along with other background information, is available on Xylitol.com (a Web site provided by the Finnish company Leaf, which makes xylitol products). In essence, xylitol's anticariogenic effect is based on a biochemical feature of this sugar alcohol: It has five carbon atoms instead of the six carbon atoms found in sweeteners such as sorbitol, fructose and glucose. As a result, the bacteria in the mouth that cause dental cariesi--streptococcus metans is the worst offender--cannot ferment xylitol in their metabolism. (63)

When a person consumes xylitol the bacteria do not receive the energy supplied by ordinary sugar (sucrose) that enables them to grow, produce acids and launch an "acid attack." During this attack--which lasts more than a half hour after sugar has been consumed--the pH of plaque formed by the bacteria falls below 5.5. Consequently, calcium and phosphate salts begin to dissolve from the surface of the tooth enamel and cavities slowly begin to form. With xylitol, the pH of saliva and plaque does not fall, acid does not form, the bacteria do not absorb well on the teeth, and the plaque level decreases. (64)

A second anticariogenic effect of xylitol is to stimulate a more alkaline saliva than do other sugar products. This mechanism helps the saliva to correct incipient damage to enamel because the plaque pH may rise above 7 after xylitol products are used. Therefore, the calcium and phosphate salts in the saliva can reach parts of the enamel where they are deficient and the sites begin to harden again. (65)

Research supporting xylitol's effectiveness includes the following:

* A randomized controlled trial of 61 children found a greater shift from higher scores for streptococcus mutans (S. mutans) to lower scores among subjects who chewed xylitol gum than those in the control group. (66)

* A review of 14 clinical studies published between 1966 and 2001 concluded that the "studies demonstrated a consistent decrease in dental caries, ranging from 30 to 60%, among subjects using sugar substitutes" compared with controls. Subjects using xylitol had the highest reductions in caries. (67)

* A five-year randomized controlled study of 740 10-year-old children found that after three years, the groups using xylitol candies on school days had a highly significant reduction of 35% to 60% in the incidence of caries compared with control groups. (68)