In moving toward a healthier way of eating, many people reduce their intake of added sugars.

This has led to a surge in the popularity of sugar substitutes, such as sugar alcohols.

Sugar alcohols are added to foods, including baking mixes, cereals, and ice cream, to give them a sweet taste without the negative side effects associated with regular sugar.

They’re healthier alternatives to regular sugar, but some people may wonder how they affect the body and whether they cause any side effects.

This article reviews what sugar alcohols are, how they affect health, and the downsides to consider if you choose to add them to your diet.

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Sugar alcohols, or polyols, are carbohydrates. As the name implies, they are hybrids of sugar molecules and alcohol molecules.

Some sugar alcohols, such as erythritol and sorbitol, occur naturally in foods like fruits and vegetables. However, the sugar alcohols that many companies use to sweeten foods are produced industrially in a variety of ways (1, 2).

While some people think they’re zero-calorie sweeteners, sugar alcohols are considered to be low calorie sweeteners (LCSs) (1, 2).

Sugar alcohols are about 25–100% as sweet as sugar, but they’re lower in calories and don’t have the same negative effects as regular sugar, such as promoting tooth decay and significantly raising blood sugar levels (2).

They’re considered low digestible carbs, meaning that when you eat them, your small intestine doesn’t completely absorb them. Instead, they travel to your large intestine, where bacteria ferment them.

Fiber and resistant starch are also considered low digestible carbs.

Interestingly, similarly to fiber, certain sugar alcohols may contribute to a healthy digestive system by promoting the growth of beneficial bacteria (2).

Currently, eight sugar alcohols are approved for human consumption (3, 4):

  • erythritol
  • hydrogenated starch hydrolysates
  • isomalt
  • lactitol
  • mannitol
  • maltitol
  • sorbitol
  • xylitol

Of these, xylitol, erythritol, and maltitol are the most widely used in the food industry. This is because their flavor most closely resembles the taste of regular sugar (5).

Because sugar alcohols’ chemical structure is similar to that of sugar, they activate the sweet taste receptors on your tongue (6, 7).

Summary

Sugar alcohols are a type of carb widely used as low calorie sweeteners. Although they closely resemble the taste of sugar, they don’t exert the same negative effects of sugar, such as causing dental cavities and significantly spiking blood sugar levels.

As mentioned above, eight types of sugar alcohols are approved for human consumption (3).

Because xylitol, erythritol, and maltitol most closely mimic the taste of regular sugar, you’ll come across these three sweeteners more frequently than other types of sugar alcohols.

Sugar alcohols differ in taste, calorie content, and the way they affect the body.

Xylitol

Xylitol is one of the most commonly used sugar alcohols because its taste closely mimics that of sugar.

It’s a common ingredient in sugar-free chewing gums, mints, and oral care products like toothpaste.

Xylitol is the sweetest of all sugar alcohols but has about 40% fewer calories than regular sugar. People tend to tolerate xylitol well, but you may experience some digestive symptoms if you consume it in large amounts (8, 9).

Erythritol

Erythritol is another sugar alcohol that’s considered to have an excellent taste.

It has 70% of the sweetness of sugar but only 5% of the calories (10).

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 by your small intestine, then spread throughout the body before being excreted unchanged in your urine (11).

Sorbitol

Sorbitol has a smooth mouthfeel and cool taste.

It’s 60% as sweet as sugar with about 60% of the calories. It’s a common ingredient in sugar-free foods and drinks, including jelly spreads and soft candy.

It has very little effect on your blood sugar and causes minimal digestive symptoms when you consume less than 10 grams. However, it may cause digestive issues like belly pain and diarrhea if you consume more than 20 grams (11).

Maltitol

Maltitol has a very similar taste and mouthfeel to regular sugar. It is 75–90% as sweet as sugar with almost half the calories.

Like other sugar alcohols, maltitol is poorly absorbed by the small intestine, so it doesn’t get absorbed into your bloodstream quickly and therefore doesn’t have the same effect on blood sugar or insulin levels as sugar does (12).

Other sugar alcohols

Other sugar alcohols that are commonly found in some food products include:

  • mannitol
  • isomalt
  • lactitol
  • hydrogenated starch hydrolysates
Summary

Many different sugar alcohols are found in the modern diet. Xylitol, erythritol, and maltitol are the most commonly used ones in food production because they taste the most like regular sugar.

The glycemic index (GI) is a measure of how quickly foods raise blood sugar levels. The glycemic index ranges from 0–100.

The lower the GI index of a food, the slower your blood sugar level rises after you consume that food. That means a lower GI index food is healthier than a higher GI index food.

The graph below compares the GI of sugar alcohols. For reference, the GI of sucrose, or table sugar, is 65. The relative sweetness indicates how sweet each sugar alcohol tastes compared with table sugar (13).

NameRelative sweetnessGlycemic index (GI)
Erythritol0.631
Xylitol0.9712
Mannitol0.502
Sorbitol0.584
Isomalt0.542
Lactitol0.353
Maltitol0.8735

As you can see from the GI values listed above, most sugar alcohols have negligible effects on blood sugar levels.

Even though some, like maltitol and xylitol, have higher GIs than the other sugar alcohols, they’re still very low compared with the GI of regular sugar.

This means that replacing regular sugar with sugar alcohols may have a beneficial effect on blood sugar levels and help people with conditions like diabetes better manage their blood sugar levels.

Summary

Most sugar alcohols have little effect on blood sugar and insulin levels. Even though some have a higher GI than others, all have significantly lower effects on blood sugar levels than regular sugar.

Tooth decay is a well-documented side effect of consuming too much sugar.

When you consume sugary foods or drinks, certain bacteria in your mouth ferment the sugar. These bacteria then multiply and secrete acids that erode the protective enamel on your teeth.

In contrast, sugar alcohols like xylitol and erythritol may protect against tooth decay (14, 15).

That’s one of the main reasons they’re so popular in many chewing gums and toothpastes.

Xylitol is well known for its beneficial effects on dental health and has been studied thoroughly (8).

Xylitol promotes dental health by reducing plaque formation, inhibiting tooth demineralization, and preventing the growth of harmful bacteria (16).

Studies have shown that erythritol appears to have similar effects on dental health and may reduce the risk of cavities (15, 17).

Summary

Some sugar alcohols may have the opposite effect as table sugar on dental health. Studies have shown that xylitol and erythritol may improve dental health and protect against cavities.

Sugar alcohols have a number of other potential benefits worth highlighting.

May help those with diabetes

Because most sugar alcohols have a minimal effect on blood sugar levels, they make a smart sugar replacement for those with prediabetes and diabetes.

However, more research is needed to understand how long-term sugar alcohol consumption affects the overall health of people with diabetes (18).

May benefit gut health

Some sugar alcohols like maltitol may promote the growth of beneficial bacteria, such as Bifidobacteria, in the gut. However, more human research is needed to assess how sugar alcohol consumption influences gut bacteria (2, 19).

Summary

Sugar alcohols may promote gut health and be a smart sugar alternative for those with diabetes. However, more research is needed to assess the overall health effects of consuming sugar alcohols.

Sugar alcohols come with a few downsides you should be aware of before adding them to your diet.

Digestive issues

The main problem with sugar alcohols is that some can cause gastrointestinal side effects in people with and without digestive conditions like irritable bowel syndrome (IBS), especially when consumed in large amounts.

Your body cannot digest most of them, so they travel to the large intestine, where your gut bacteria break them down.

For this reason, if you eat a lot of sugar alcohols in a short period of time, you may experience gas, bloating, and diarrhea.

For example, most people who consume under 10 grams of sorbitol won’t experience significant digestive issues, aside from a bit of gas and bloating. However, if you consume more than 20 grams, it can cause significant digestive issues, including pain and diarrhea (2).

Other sugar alcohols, like maltitol, can lead to symptoms as well, so it’s best to avoid consuming them in large amounts (12, 20).

Plus, some sugar alcohols, including sorbitol and mannitol, are considered fermentable oligosaccharides, disaccharides, monosaccharides, and polyols — also known as FODMAPs.

These are types of carbs that your gut can’t absorb very well, which may lead to gastrointestinal side effects in some people.

People who are sensitive to FODMAPs should avoid sugar alcohols, with the exception of erythritol. Erythritol is generally well tolerated and not considered a high FODMAP ingredient (21, 22).

Xylitol is toxic to dogs

While xylitol is well tolerated by humans, it’s 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 start pulling sugar out of their bloodstream. This can lead to low blood sugar and other side effects — including liver failure, which can be fatal (23).

If you have a dog, keep xylitol out of reach or just don’t buy it.

This reaction appears to only occur in dogs, and xylitol seems to be the only culprit.

Summary

Xylitol is toxic to dogs. If you own a dog, make sure to keep xylitol out of reach. Other sugar alcohols don’t have this effect.

Out of all the sugar alcohols, erythritol seems to be one of the best options. It’s also one of the most popular and commonly used types of sugar alcohol.

Here’s what makes erythritol a good option:

  • closely mimics the taste of sugar
  • contains almost no calories
  • minimally affects blood sugar levels
  • causes significantly less digestive problems than other sugar alcohols
  • good for your teeth
  • won’t harm your dog

However, even though erythritol is considered to be safe and well tolerated by humans, it doesn’t mean that you should consume large amounts of erythritol or any other sugar alcohol regularly.

To promote overall health, it’s a good idea to cut back on your consumption of added sugars, artificial sweeteners, and low calorie sweeteners like sugar alcohols.

Instead, focus on mostly whole, nutrient-dense foods like fruits, vegetables, fish, and nuts.

Summary

Erythritol is a popular sugar alcohol that has been shown to be safe and well tolerated. However, it’s important to limit your consumption of all sweeteners, including artificial sweeteners, added sugars, and low calorie sweeteners like sugar alcohols.

Sugar alcohols are popular, low calorie sweeteners that you can find in many low calorie foods and drinks.

While they’re generally well tolerated, consuming high amounts of some sugar alcohols, such as sorbitol, may cause bloating and diarrhea, especially if you consume them in large amounts.

If you’d like to cut back on added sugar, try using a bit of erythritol to provide sweetness without the negative side effects of regular sugar.

Just one thing

Try this today: If you’re trying to cut back on your overall intake of added sugar, try starting with beverages. Drinks like soda, energy drinks, and sweetened coffees can contain a shocking amount of sugar.

The first step is learning how to read nutrition labels. Four grams of sugar equal 1 teaspoon. For example, if a bottle of soda contains 40 grams of added sugar, that means you’re drinking 10 teaspoons of added sugar.

Try to reduce your total sugar consumption by replacing sugary beverages with water or cutting back on your sugary beverage intake.