Why I Use Xylitol

By Dr. Mercola

Many of my readers have noticed that some of the products I recommend are sweetened with an ingredient called xylitol. Since a good number of people are unfamiliar with xylitol, I thought it would be a good idea to explain what it is, why I think it’s an acceptable sweetener, and what you might need to know about it.

Xylitol is a sweetener of a type known as a sugar alcohol, or polyol. Sugar alcohols are neither sugars nor alcohols -- they are carbohydrates with structures that happen to resemble sugar and alcohol. Part of their structure chemically resembles sugar, and part is similar to alcohol, but they don’t completely fit into either category.

Sugar alcohols are often used in a variety of foods labeled low-calorie, reduced calorie, low-fat, and sugar-free. These foods include baked goods, candy, gum, and frozen dairy desserts, among others.

Sugar alcohols are not as sweet as sugar, but they contain fewer calories. Sugar contains about 4 calories per gram, and sugar alcohols generally range from about 1.5 calories per gram to 3 calories per gram. The chart below lists some common sugar alcohols, their sweetness, their calorie content, and where they are most often used:[1]

Foods that contain sugar alcohols can be labeled sugar-free, because the sugar alcohols replace the full calorie sugar sweeteners.

Don’t Be Fooled By “Sugar-Free” and “Low Carb” Labels

However, sugar alcohols -- including xylitol -- do not make “sugar free” foods calorie free. If foods containing sugar alcohols are eaten in large enough quantities, the calories can be comparable to sugar-containing foods. As with all foods, you need to carefully read the food labels for calorie and carbohydrate content, regardless of any claims that the food is sugar-free or low-sugar. Sugar alcohols can also be converted to fat, and may contribute to an increase in blood triglyceride levels and weight gain.[2]

The same warning applies to “low-carb” foods. There are many “low-carb” products on the market containing sugar alcohols as their sweeteners. You will often find the claim, “Only 1 gram of net* carbs!” in bold letters on their labels. The back label, however, states that each bar actually has 19 or 20 grams of carbohydrates, but that these carbs don’t count because they don’t raise blood sugar levels.

According to Richard Bernstein, M.D., author of the best selling book Dr. Bernstein’s Diabetes Solution, this is simply not the case: “Although it is true that sugar alcohols do not raise blood sugars as quickly or as much as sugar, they will still raise blood sugars and should be avoided by diabetics and anyone who is overweight.”[3]

Maltitol, a commonly used sugar alcohol, is probably the worst of the lot for this, spiking blood sugar almost as much as a starchy new potato.[4] Xylitol, in comparison, does not spike blood sugar much at all, having the same effect as small amounts of more complex carbohydrates, such as asparagus, eggplants, spinach, or squash.[5]

Are Sugar Alcohols Safe?

Sugar alcohols are found in very low levels in some raw fruits and vegetables, and do not cause problems in this natural state. However, the highly processed sugar alcohols often used in the diet industry are very different from the ones found in nature. And some sugar alcohols are much, much better than others.

One reason that sugar alcohols provide fewer calories than sugar is because they are not completed absorbed into your body. Because of this, eating many foods containing sugar alcohols can lead to abdominal gas and diarrhea.

Sugar alcohols can cause adverse digestive side-effects including bloating, gastrointestinal distress and anal leakage at moderate consumption levels of 15 grams (1.5 teaspoons) per day.[6] Sorbitol and mannitol are particularly prone to causing this problem, and any foods that contain either ingredient must include a warning on their label that "excess consumption may have a laxative effect."

These detrimental side effects can also result in dehydration, equilibrium loss, vitamin and mineral depletion, malnutrition, and a higher vulnerability to disease. This can happen at lower dosage levels (as little as 1 gram, or 1/10^th pf a teaspoon, per day) in infants, children, diabetics, hyper-insulin or hypoglycemics, pregnant woman, seniors, and many other health compromised populations.

When I attended the largest natural food products expo in Los Angeles in March of this year, I took several trips up and down the aisles, sampling many of the food products. By the end of the day, I was suffering from nausea, stomach cramping, and loose stools as a result of the high number of foods I sampled that contained sugar alcohols. I vowed to be more cautious in the future, keeping my sugar alcohol intake to only one bite.

Maltitol and Cancer

Some sugar alcohols have been directly medically linked with cancer causing malignant tumor activity.[7] Once again maltitol, which is the most common sugar alcohol used in low-carb snack bars and chocolate, has a particularly troublesome history. It was denied Generally Recognized as Safe (GRAS) status in 1994 by the FDA as a result of a significant number of laboratory animals contracting malignant intestinal tumors in USDA run tests, at relatively low ingestion levels.

Xylitol -- The Clear Winner

Even bearing all of that in mind, I still would recommend sugar alcohols far above artificial sweeteners such as aspartame, which causes a laundry list of health problems that make sugar alcohols seem relatively innocuous. Also, as I said before, some sugar alcohols are better than others. Of the sugar alcohols, the clear “winner” is xylitol.

Xylitol is a high-grade sweetener extracted from birch cellulose. As I already mentioned, it is one of the sugar alcohols that does not cause a severe spike in blood sugar levels. It also comes with an added benefit, because it is anti-bacterial -- many studies show that it actually helps prevent dental cavities.[8]^,[9] That is why it is often used in toothpastes, mouthwashes, breath mints and sprays, and pharmaceutical products such as cough syrups, cough drops, and throat lozenges.

Xylitol is even used in products such as nasal wash to prevent nasal or throat infections, and it is very effective in that application. Xylitol has also been reported to be useful in preventing ear infections,[10] and some evidence suggests that it can help prevent gum disease.[11] Bacterial salivary organisms do not feed, grow or ferment on xylitol as they do on simple sugars.

This is not the case for all sugar alcohols -- sorbitol and mannitol, for example, are industrial sweet alcohols made from hydrogen and commercial glucose, extracted from corn sugar. Both are known to nourish and increase the count of mouth bacteria, especially Streptococcus mutans, which tends to stick to your teeth.[12] When you then eat other sugars, these bacteria proliferate, creating the perfect chemistry for increasing the tooth decay beyond the normal rate.

Pure xylitol also does not usually produce the gas or bloating associated with other sugar alcohols. Some products which are labeled as being sweetened with xylitol, however, can unfortunately still have this effect, because they do not use pure xylitol. Manufacturers will add other products to the xylitol to cheapen the cost. Low-grade xylitol is typically contaminated with other sugar alcohols, most notably sorbitol, which is much more likely to cause digestive problems. So if you wish to avoid those problems, make sure that high-grade xylitol is the sweetener being used -- it will be somewhat more expensive, but in my experience it is well worth it.

The Final Word

Sweeteners vary greatly in how healthy they are. The worst kind of sweeteners you can consume are the artificial, lab-produced types such as aspartame or nutrasweet, which have no resemblance to anything actually found in nature. The best are those consumed as they are found in nature, unrefined and in small quantities, such as small quantities of whole fruits, raw honey or herbs like stevia.

Sugar alcohols lie somewhere between the two poles, and in moderation some of them can be a better choice than highly refined sugar or high fructose corn syrup. They can have side effects, and should be consumed only in moderation. But while they are processed and do contain calories, the better ones are less likely to spike your blood sugar than refined sugar.

Of the various sugar alcohols, xylitol is one of the best. When it is pure, the potential side effects are minimal, and it actually comes with some benefits such as fighting tooth decay. All in all, I would say that xylitol is reasonably safe, and potentially even a mildly beneficial sweetener.

However, stevia remains my favorite sweetener. Unfortunately the FDA has made it illegal to use as a sweetener, so it can only be sold as a nutritional herb.