Xylitol

Added sugar may be the single most unhealthy ingredient in the modern diet.

For this reason, sugar-free sweeteners like xylitol are becoming popular.

Xylitol looks and tastes like sugar but has fewer calories and doesn't raise blood sugar levels.

Several studies suggest that it has various important benefits, including improved dental health.

This article examines xylitol and its health effects.

Xylitol is categorized as a sugar alcohol.

Chemically, sugar alcohols combine traits of sugar molecules and alcohol molecules. Their structure allows them to stimulate the taste receptors for sweetness on your tongue.

Xylitol is found in small amounts in many fruits and vegetables and is therefore considered natural. Humans even produce small quantities of it via normal metabolism.

It is a common ingredient in sugar-free chewing gums, candies, mints, diabetes-friendly foods and oral-care products.

Xylitol has a similar sweetness as regular sugar but contains 40% fewer calories:

  • Table sugar: 4 calories per gram
  • Xylitol: 2.4 calories per gram

Store-bought xylitol appears as a white, crystalline powder.

Since xylitol is a refined sweetener, it doesn't contain any vitamins, minerals or protein. In that sense, it provides only empty calories.

Xylitol can be processed from trees like birch or from a plant fiber called xylan (1).

Even though sugar alcohols are technically carbohydrates, most of them do not raise blood sugar levels and thereby don't count as net carbs, making them popular sweeteners in low-carb products (2).

Though the word “alcohol” is part of its name, it’s not the same alcohol that makes you drunk. Sugar alcohols are safe for people with alcohol addictions.

Summary Xylitol is a sugar alcohol that occurs naturally in some plants. Though it looks and tastes like sugar, it has 40% fewer calories.

One of the negative effects of added sugar — and high-fructose corn syrup — is that it can spike blood sugar and insulin levels.

Due to its high levels of fructose, it can also lead to insulin resistance and multiple metabolic problems when consumed in excess (3, 4).

However, xylitol contains zero fructose and has negligible effects on blood sugar and insulin (2, 5).

Therefore, none of the harmful effects of sugar apply to xylitol.

Xylitol’s glycemic index (GI) — a measure of how quickly a food raises blood sugar — is only 7, whereas regular sugar’s is 60–70 (6).

It can also be considered a weight-loss-friendly sweetener since it contains 40% fewer calories than sugar.

For people with diabetes, prediabetes, obesity or other metabolic problems, xylitol is an excellent alternative to sugar.

While corresponding human studies are currently unavailable, rat studies show that xylitol can improve symptoms of diabetes, reduce belly fat and even prevent weight gain on a fattening diet (7, 8, 9).

Summary Unlike sugar, xylitol has negligible effects on blood sugar and insulin levels. Animal studies indicate impressive benefits for metabolic health.

Many dentists recommend using xylitol-sweetened chewing gum — and for good reason.

Studies have determined that xylitol boosts dental health and helps prevent tooth decay (10).

One of the leading risk factors for tooth decay is an oral bacteria called Streptococcus mutans. This is the bacteria most responsible for plaque.

Although some plaque on your teeth is normal, excess plaque encourages your immune system to attack the bacteria in it. This can lead to inflammatory gum diseases like gingivitis.

These oral bacteria feed on glucose from food, but they can not use xylitol. As such, replacing sugar with xylitol reduces the available fuel for the harmful bacteria (11).

While these bacteria cannot use xylitol for fuel, they still ingest it. After absorbing xylitol, they are unable to take up glucose — meaning that their energy-producing pathway is clogged and they end up dying.

In other words, when you chew gum with xylitol or use it as a sweetener, the harmful bacteria in your mouth starve to death (12).

In one study, xylitol-sweetened chewing gum reduced levels of bad bacteria by 27–75%, while friendly bacteria levels remained constant (13).

Animal studies also suggest that xylitol may increase absorption of calcium in your digestive system, protecting against osteoporosis and strengthening your teeth (14, 15).

Human studies demonstrate that xylitol — either by replacing sugar or adding it into your diet — can reduce cavities and tooth decay by 30–85% (16, 17, 18).

Because inflammation is at the root of many chronic diseases, reducing plaque and gum inflammation could have benefits for the rest of your body as well.

Summary Xylitol can starve the harmful bacteria in your mouth, reducing plaque buildup and tooth decay. This can help prevent dental cavities and inflammatory gum diseases.

Your mouth, nose and ears are all interconnected.

Therefore, bacteria that live in the mouth can end up causing ear infections — a common problem in children.

It turns out that xylitol can starve some of these bacteria in the same way that it starves plaque-producing bacteria (19).

One study in children with recurring ear infections observed that daily usage of xylitol-sweetened chewing gum reduced their infection rate by 40% (20).

Xylitol also fights the yeast Candida albicans, which can lead to candida infections. Xylitol reduces the yeast’s ability to stick to surfaces, thereby helping prevent infection (21).

Summary Xylitol-sweetened gum can reduce ear infections in children and combat candida yeast infections.

Collagen is the most abundant protein in your body, found in large amounts in skin and connective tissues.

Some studies in rats link xylitol to increased production of collagen, which may help counteract the effects of aging on your skin (22, 23).

Xylitol may also be protective against osteoporosis, as it leads to increased bone volume and bone mineral content in rats (14, 24).

Keep in mind that studies in people are needed to confirm these benefits.

Xylitol also feeds the friendly bacteria in your gut, acting as a soluble fiber and improving your digestive health (25).

Summary Xylitol may increase collagen production and reduce your risk of osteoporosis. It also feeds the friendly bacteria in your gut.

In humans, xylitol is absorbed slowly and has no measurable effect on insulin production.

However, the same cannot be said for dogs.

When dogs eat xylitol, their bodies mistake it for glucose and start producing large amounts of insulin.

Then the dog's cells start absorbing glucose from the bloodstream, which can lead to hypoglycemia, or low blood sugar, and even death (26).

Xylitol may also have detrimental effects on liver function in dogs, with high doses causing liver failure (27).

It only takes 0.1 grams per kg of body weight for a dog to be affected, so a 6–7-pound (3-kg) chihuahua will get sick from eating just 0.3 grams of xylitol. That’s less than the amount contained in a single piece of chewing gum.

If you own a dog, keep xylitol safely contained or out of your house altogether. If you believe your dog accidentally ate xylitol, take it to your vet immediately.

Summary Xylitol is highly toxic to dogs, leading to hypoglycemia and liver failure.

Xylitol is generally well tolerated, but some people experience digestive side effects when they consume too much.

The sugar alcohols can pull water into your intestine or get fermented by gut bacteria (28).

This can lead to gas, bloating and diarrhea. However, your body seems to adjust very well to xylitol.

If you increase intake slowly and give your body time to adjust, you likely won't experience any negative effects.

Long-term consumption of xylitol does appear to be completely safe.

In one study, people consumed an average of 3.3 pounds (1.5 kg) of xylitol per month — with a maximum daily intake of over 30 tablespoons (400 grams) — without any negative effects (29).

People use sugar alcohols to sweeten coffees, teas and various recipes. You can replace sugar with xylitol in a 1:1 ratio.

If you have irritable bowel syndrome (IBS) or an intolerance to FODMAPs, be careful with sugar alcohols and consider avoiding them altogether.

Summary Xylitol may cause digestive upset in some people, but high doses are well tolerated by others.

As a sweetener, xylitol is an excellent choice.

Whereas some sweeteners may cause health risks, studies show that xylitol has actual health benefits.

It doesn't spike blood sugar or insulin, starves the plaque-producing bacteria in your mouth and feeds friendly microbes in your digestive system.

If you're looking for a healthier alternative to regular sugar, give xylitol a try.