Xylitol in white bowl with candy sugar sticks

One of the first steps we recommend to nourishing ourselves and our children is to replace sugar with natural sweeteners in moderation. Some ask why xylitol isn’t on our list of natural sweeteners? Rami Nagel explains why we don’t recommend it in his article, Agave Nectar of the Gods, which appeared in the Summer 2008 quarterly Wise Traditions journal of the Weston A. Price Foundation:

Author Rami Nagel

Xylitol: Is It Beneficial, or Even Safe?

Heralded as an ally in the battle against tooth decay and diabetes, xylitol is another sweetener to enter the market with a great deal of hype. Xylitol is a five-carbon sugar alcohol found in some fruits and vegetables and produced in small amounts by the human body. Because mouth bacteria cannot ferment sugar alcohols, xylitol is said to prevent cavities; and because the body metabolizes it primarily through the liver rather than the pancreas, [1] it is said to be good for diabetics in limited amounts (no more than 60 grams per day).

Xylitol is less sweet than sugar and produces a noticeable cooling sensation in the mouth when highly concentrated, as in “sugar-free” candy and chewing gum. It is often added to foods sweetened with aspartame, to mask the bitter taste. And because xylitol contains fewer calories than sugar, products containing it can carry weight loss claims.

How Is Xylitol Made?

Originally made from birch bark, and hence associated with the very natural, nutritious and traditional birch syrup (similar to maple syrup), xylitol is anything but a natural product. The typical manufacturing process goes like this: Obtain some source material containing xylan. One commonly used source is corn cobs imported from China. Hardwood and the waste from cotton ginning are other sources.

The xylan needs to be broken down, either through a chemical process called acid hydrolyzing or through microbial fermentation. (Genetically engineereed bacteria have been proposed for this step.) The results of this process are xylose and acetic acid. The concentrated acetic acid, described as “very hazardous in case of skin contact (irritant), of eye contact (irritant), of ingestion, of inhalation … Hazardous in case of skin contact (corrosive, permeator), of eye contact (corrosive),” must be removed. Next the hydrolyzing acid and organic residues must be removed, which is done by heating the mixture and evaporating it. The resulting syrup is now free of acetic acid, hydrolyzing acid, and other residues. The syrup is crystallized by stirring ethanol into it. The crystalline xylitol is now separated in a centrifuge. The ethanol is separated from the sorbitol remaining in solution. Voilà! You have xylitol.

Xylitol’s Dubious Health Claims

Since xylitol is an industrial product, it pays to be dubious about the industry’s health claims for it. First among these is the claim that xylitol prevents cavities. Indeed, many studies can be cited to support such a claim. But not all. The results of a recent two-year trial found no difference in cavities between those who chewed xylitol-containing gum and those who did not. In an earlier study, researchers concluded that “Overall, consumption of xylitol-containing snacks and candy did not reduce S. mutans levels.”

As for the claim that xylitol is good for diabetics, the fact that this sweetener is not completely absorbed comes at a cost: bloating, diarrhea and flatulence. In a study performed on 18 diabetic children who consumed a dose of 30 grams of xylitol per day, researchers found a significant elevation of the uric acid concentration.[2] And since 80 percent of xylitol is metabolized through the liver, a danger to liver function similar to that of fructose is a distinct possibility.

The official website for xylitol states, “In the amounts needed to prevent tooth decay (less than 15 grams per day), xylitol is safe for everyone.” Fifteen grams of xylitol is about 0.5 ounces. What about doses over 15 grams?

In a long term toxicology study on rats researchers found that xylitol caused a significant increase in the incidence of adrenal medullary hyperplasia in male and female rats in all dose levels tested (5%, 10% and 20%).[3] That means it caused abnormal cell growth in the adrenal glands. In one higher-dose study in which mice consumed 20 percent of their diet as xylitol, there was a significant increase in the mortality of the males as compared to those consuming sucrose. A major study in dogs found an increase in liver weight associated with xylitol use. [4]

Conclusions About Xylitol

Xylitol’s own promotional material says it is not safe for everyone to use. Since children are smaller and less developed than adults, they will obviously be much more sensitive to xylitol’s effects. There are no safety data or tests to indicate a safe dosage for children. And foods containing xylitol may also contain additional sweeteners that are undeniably harmful, such as aspartame.

As for claims that xylitol can prevent tooth decay, I can only say, “Buyer beware!” Such claims are based on the faulty theory that bacteria cause tooth decay. We know from the work of Weston Price that tooth decay is a problem of nutrient deficiencies—the bacteria are just there cleaning up dead tissue.

Finally, and most importantly, this industrial product is just not necessary. Nature has provided us with many wholesome sweeteners that can be used in moderation without adverse effects in the context of a diet of nutrient-dense traditional foods.


1. Dehmel KH and others. Absorption of xylitol. Int. Symp on metabolism, physiology and clinical use of pentoses and pentitols. Hakone, Japan, 1967, 177-181, Ed. Horecker.

2. Förster, H., Boecker, S. and Walther, A. (1977) Verwendung von Xylitals Zuckeraustauschstoff bei diabetischen Kindern, Fortschr. Med.,95, nr. 2, 99-102.

3. Russfield, A.D. (1981) Two-year feeding study of xylitol, sorbitol and sucrose in Charles River (UK) rats: Adrenal Medulla. Unpublished report.

4. Heywood, R. et al. (1981) Revised report: Xylitol toxicity study in the beagle dog (Report of Huntingdon Research Centre).

About the Author

Rami Nagel describes himself as a father who cares about the way we affect each other, our children and our planet through our lifestyle choices. His health background is in hands-on energy healing, Hatha and Bhaki yoga, and Pathwork. Rami has written the bestselling book Cure Tooth Decay, as well as Cure Gum Disease Naturally.