Xylitol is a naturally occurring substance that is widely used as a sugar substitute. Chemically, it is a sugar alcohol, and in nature it is found in berries, plums, corn, oats, mushrooms, lettuce, trees, and some other hardwood trees and fruits.
Commercially, most xylitol is extracted from corn fiber, birch trees, hardwood trees and other vegetable material. Although it has been used as a sugar substitute for decades, its popularity has increased dramatically in the last few years.
Xylitol is manufactured into a white powder that looks and tastes similar to sugar. In many countries it has been approved for use in oral care products, pharmaceuticals and as a food additive. Products that may contain xylitol include sugar-free gum, candies, breath mints, baked goods, cough syrup, children's chewable vitamins, mouthwash, and toothpaste, to list a few.
Xylitol is about as sweet as sucrose, but contains only about two-thirds of the calories. As a sugar substitute, it is lower on the glycemic index, a scale that ranks carbohydrate-rich foods by how much they raise blood sugar levels compared to glucose. Being lower on the glycemic index makes xylitol useful for diabetics or people on low carbohydrate diets.
With respect to oral health, research has shown that xylitol helps reduce the formation of plaque, inhibits dental cavities, and stimulates the production of saliva.
Xylitol is safe for use in humans. Xylitol, like most sugar alcohols, may have a mild laxative effect when eaten in large amounts, when first introduced to a diet. This occurs because, until the digestive system adapts, xylitol may not be completely digested in the intestines. This causes mild diarrhea and/or mild intestinal discomfort.
However, xylitol is extremely toxic to dogs. Even small amounts of xylitol can cause hypoglycemia (low blood sugar), seizures, liver failure or even death in dogs.