For decades, sugar alcohols have been popular alternatives to sugar.
They look and taste like sugar, but have fewer calories and fewer negative health effects.
In fact, many studies show that sugar alcohols can lead to health improvements.
This article examines sugar alcohols and their health effects.
Sugar alcohols are a category of sweet carbohydrates.
Since sugar alcohols are partially resistant to digestion, they act like dietary fiber. They’re also a type of FODMAP, which may cause stomach upset and bloating in some people.
As the name implies, they are like hybrids of sugar molecules and alcohol molecules.
Despite the "alcohol" part of the name, they do not contain any ethanol, the compound that makes you drunk. Sugar alcohols are safe for people who misuse alcohol.
Several sugar alcohols are found naturally in fruits and vegetables.
However, most are processed from other sugars, such as from glucose in cornstarch.
Because sugar alcohols have a similar chemical structure as sugar, they activate the sweet taste receptors on your tongue.
Unlike artificial and low-calorie sweeteners, sugar alcohols do contain calories, just fewer than plain sugar.
Summary Sugar alcohols are a category of sweet carbohydrates found naturally or processed from other sugars. They are widely used as sweeteners.
Several types of sugar alcohols are commonly used as sweeteners.
They differ in taste, calorie content and health impact.
Xylitol is the most common and well-researched sugar alcohol.
It’s a common ingredient in sugar-free chewing gums, mints and oral care products like toothpaste.
It is about as sweet as regular sugar but has 40% fewer calories. Aside from causing some digestive symptoms when consumed in large amounts, xylitol is well tolerated ().
Erythritol is another sugar alcohol that is considered to have an excellent taste.
It is produced by fermenting the glucose in cornstarch and has 70% of the sweetness of sugar but 5% of the calories.
Along with the low-calorie sweetener stevia, erythritol is the main ingredient in the popular sweetener blend known as Truvia.
Erythritol does not have the same digestive side effects as most other sugar alcohols because it doesn't reach your large intestine in significant amounts.
Instead, most of it gets absorbed into your bloodstream, then excreted unchanged in your urine ().
Sorbitol has a smooth mouthfeel and cool taste.
It is 60% as sweet as sugar with about 60% of the calories. What’s more, it is a common ingredient in sugar-free foods and drinks, including jelly spreads and soft candy.
It has very little effect on blood sugar and insulin but may cause digestive distress ().
Maltitol is processed from the sugar maltose and has a very similar taste and mouthfeel as regular sugar.
It is 90% as sweet as sugar with almost half the calories. While products that contain maltitol claim to be "sugar-free," your body absorbs some of this sugar alcohol, causing blood sugar spikes ().
If you have diabetes, then be skeptical of low-carb products that are sweetened with maltitol and make sure to monitor your blood sugars carefully.
Other Sugar Alcohols
Other sugar alcohols that are commonly found in some food products include mannitol, isomalt, lactitol and hydrogenated starch hydrolysates.
Summary Many different sugar alcohols are found in the modern diet. These include xylitol, erythritol, sorbitol, maltitol and numerous others.
The glycemic index (GI) is a measure of how quickly foods raise blood sugar levels.
Consuming foods that are high on the GI is associated with obesity and numerous metabolic health problems (5, ).
The graph below compares the GI of several sugar alcohols with sucrose — pure table sugar or white sugar — and the artificial sweetener sucralose ().
As you can see, most sugar alcohols have a negligible effect on blood sugar levels. In the case of erythritol and mannitol, the glycemic index is zero.
The only exception is maltitol, which has a glycemic index of 36. However, this is still very low compared to sugar and refined carbohydrates.
For people with metabolic syndrome, prediabetes or diabetes, sugar alcohols — except perhaps maltitol — can be considered excellent alternatives to sugar.
Summary Most sugar alcohols have little to no effect on blood sugar and insulin levels — with the exception of maltitol.
Tooth decay is a well-documented side effect of excess sugar consumption.
The sugar feeds certain bacteria in your mouth, which multiply and secrete acids that erode the protective enamel on your teeth.
In contrast, sugar alcohols like xylitol, erythritol and sorbitol protect against tooth decay ().
That's one of the main reasons they are so popular in many chewing gums and toothpastes.
Xylitol is well known for its beneficial effects on dental health and has been studied thoroughly (, ).
In fact, the bad bacteria in your mouth feed on xylitol but are unable to metabolize it, so it ends up clogging their metabolic machinery and inhibiting their growth ().
Erythritol has not been studied as extensively as xylitol, but one three-year study in 485 schoolchildren found that it was more protective against dental cavities than xylitol and sorbitol ().
Summary Xylitol, erythritol and sorbitol lead to improvements in dental health. Xylitol has been studied most, but some evidence suggests erythritol is the most effective.
Sugar alcohols have a number of other potential benefits worth highlighting:
- Prebiotic: Sugar alcohols may feed the friendly bacteria in your gut, having a prebiotic effect like dietary fiber (, , ).
- Bone health: Many rat studies indicate that xylitol can increase bone volume and mineral content, which should protect against osteoporosis (, ).
- Skin health: Collagen is the main structural protein in your skin and connective tissues. Studies in rats demonstrate that xylitol can increase collagen production (, ).
Summary Sugar alcohols may feed the friendly bacteria in your gut and have been shown to positively impact bones and skin in animal studies.
The main problem with sugar alcohols is that they can cause digestive problems, especially when consumed in large amounts.
Your body cannot digest most of them, so they travel to the large intestine where they are metabolized by your gut bacteria.
If you eat a lot of sugar alcohols in a short period of time, you may experience gas, bloating and diarrhea.
If you have irritable bowel syndrome (IBS) or a sensitivity to FODMAPs, you may want to consider avoiding sugar alcohols completely.
Sorbitol and maltitol appear to be the biggest offenders, while erythritol and xylitol cause the fewest symptoms ().
Summary When consumed in large amounts, most sugar alcohols cause significant digestive distress. The impact depends on the individual and the type of sugar alcohol.
Xylitol is well tolerated by humans but highly toxic to dogs.
When dogs eat xylitol, their bodies mistake it for sugar and start producing large amounts of insulin.
When insulin goes up, dogs’ cells starts pulling sugar from the bloodstream.
This can lead to hypoglycemia (low blood sugar) and can be fatal ().
If you have a dog, keep xylitol out of reach or refrain from buying it.
This reaction appears exclusive to dogs. Xylitol — not other sugar alcohols — seems the only culprit.
Summary Xylitol is toxic to dogs. If you own a dog, make sure to keep xylitol out of reach.
Out of all the sugar alcohols, erythritol seems to be one of the best options.
It has almost no calories, no effect on blood sugar and causes significantly less digestive problems than the others.
It is also good for your teeth and won't end up harming your dog.
Plus, it tastes great — it's basically sugar without the calories.
Summary Erythritol is generally considered one of the healthiest sugar alcohols. It’s calorie-free, doesn’t raise blood sugar levels and is less likely to cause digestive upset than the other sugar alcohols.
Sugar alcohols are popular, low-calorie sweeteners. They are not artificial sweeteners.
They are partially resistant to digestion — though certain sugar alcohols, such as maltitol, may cause a slight rise in blood sugar levels.
While they are well tolerated, high amounts of some sugar alcohols, such as sorbitol, may cause bloating and diarrhea.
Erythritol seems to produce the fewest side effects and may be a good choice if you have an intolerance to FODMAPs.