Dangers of sugar alcohols

If you’re conscious of your sugar intake (perhaps especially if you have diabetes), you’re probably a pro at reading food labels. But how much do you know about products that use sugar alcohols as a sweetener?

“Sugar alcohols may have a minor impact on your blood sugar levels, but in general they have long been thought to be safe to include as part of a balanced diet,” says registered dietitian Tegan Bissell, RD, LD. “However, new research shows that this may not be as true as we once thought.”

We spoke with Bissell and physician-scientist Stanley Hazen, MD, PhD, to understand what sugar alcohols are and the potential risks that emerge.

What are sugar alcohols?

The term itself is actually misleading: there is no ethanol in sugar alcohols, and there is no table sugar either. “Sugar alcohols are a type of carbohydrate and have a chemical structure similar to sugar,” Bissell explains.

Although they occur naturally in some foods and are produced by your body, the concentrations present are negligible. Most sugar alcohols found in packaged foods are man-made and manufactured. Food manufacturers use these sugar alcohols to sweeten their products while reducing calories.

“Sugar alcohols stimulate the tongue’s sweet taste buds, adding flavor without extra sugar or calories,” Bissell explains. “Food companies use them so they can market their food as ‘low-carb’, ‘sugar-free’ or ‘diabetes-friendly’ without sacrificing taste.”

For this reason, they are often found in products labeled “diabetes-friendly” or “keto-friendly.” Common sugar alcohols include:

• Xylitol.
• Erythritol.
• Sorbitol.
• Maltitol.
• Mannitol.
• Isomalt.
• Lactitol.

More information about the individual ingredients soon. But now let’s dig a little deeper into what sugar alcohols do in general.

Sugar Alcohols vs. Artificial Sweeteners

Sugar alcohols are sometimes called artificial sweeteners, a category that also includes aspartame and saccharin, but in reality they are not the same. Although they are both manufactured, they differ in some important ways.

“Sugar alcohols have very few calories and are not as sweet as sugar,” notes Bissell. “Artificial sweeteners, on the other hand, are chemicals that provide an intense level of sweetness and contain no calories.”

You can also purchase artificial sweeteners as a sugar substitute for baking and cooking and find them in packets at restaurants and coffee shops. Sugar alcohols are often used in processed foods.

Sugar alcohols vs. sugar

Sugar is 100% natural and comes exclusively from fruits, plants, vegetables and milk. Although some sugar alcohols come from fruits and vegetables, the sugar alcohols used in processed foods are artificially produced.

Sugar alcohols have some advantages over regular sugar, including:

• Fewer calories: Unlike sugar, which contains about 4 calories per gram, sugar alcohols contain between 0 and 2 calories per gram. “They taste almost as sweet as sugar, with about half the calories – or less,” says Bissell.
• Easier blood sugar management: Unlike regular sugar, sugar alcohols do not cause sudden blood sugar spikes. “They are considered low glycemic index foods and may cause only a mild increase in blood sugar levels,” she adds. “That’s why they’re used in commercially produced, packaged snacks and candies and often marketed as ‘good for diabetes.’
• Less dental risk: Sugar alcohols don’t react to plaque like sugar, meaning they don’t contribute to tooth decay. “You may see the sugar alcohol xylitol as an ingredient in your toothpaste, making it taste better and helping prevent cavities,” Bissell explains.
• Fewer carbohydrates: Sugar alcohols fit into a low-carb diet because they contain much fewer carbohydrates and have a lower glycemic index than regular forms of sugar.

Sounds great, right? Not so fast. There is another important difference between sugar and sugar alcohols.

“Your body can easily digest sugar and use it for energy,” Bissell explains. “But it cannot absorb or fully digest sugar alcohols.” It turns out that this can cause some problems.

Risks of sugar alcohols

Sugar alcohols have long been considered a safe addition to your diet – in moderation. Research has shown that 10 to 15 grams of sugar alcohols per day is safe. But many processed foods that contain sugar alcohols have levels much higher than that threshold. And new research shows that elevated levels of sugar alcohols could be dangerous to your health.

1. Heart attack and stroke

Dr. Hazen and his team have conducted studies on the effects of both xylitol and erythritol. And the findings are very worrying.

Circulating levels of both xylitol and erythritol have been shown to be associated with an increased risk of ‘major adverse cardiovascular events’. That includes an increased risk of heart attack, stroke and even death.

Now association is not the same as causation. But studies in blood, platelets, and non-human models all indicate that erythritol and xylitol increase blood clotting risks (what happens in a heart attack or stroke). The concern is that eating foods with these sugar alcohols could put you at a higher risk of heart attack and stroke.

High levels of xylitol and erythritol can send your platelets into overdrive. Platelets are the components in your blood that help it clot. Clotting is a good thing when you have an open wound. It keeps you from bleeding. But when your blood clots in your body, it’s a recipe for a medical emergency, such as a heart attack or stroke.

It doesn’t take much either. For example, just one scoop of keto-friendly ice cream contains up to 30 grams of xylitol. From the research of Dr. Hazen shows that this is enough to agitate your platelets, making them more likely to form clots. And the increased risk lasts about four to six hours (or until you eat more xylitol-containing foods).

When you eat foods containing erythritol, the risk may last for several days.

“More research needs to be done to understand the effects of other sugar alcohols. But based on what we see with xylitol and erythritol, it’s fair to say that sugar alcohols require caution,” says Dr. Hares. “These compounds are found in foods typically marketed to people with diabetes, who are already at increased risk for serious heart events. And the sugar alcohols in their diets can unintentionally increase that risk.”

2. Gastrointestinal problems

Your body can’t fully digest sugar alcohols, which can lead to unpleasant gastrointestinal symptoms if you eat them in larger quantities — and they usually happen quite quickly after you eat them.

In a 2006 British study, researchers gave participants doses of sugar or one of two types of sugar alcohols (xylitol and erythritol). Those taking xylitol reported bloating, gas, stomach upset and diarrhea. Erythritol appeared to have milder effects on the stomach, only increasing nausea and gas when consumed in large doses.

“Eating foods containing sugar alcohols several times a day may cause abdominal discomfort and increase your risk of heart disease in the long term,” Bissell warns. “If you notice this happening, use caution or find another sweetener option.”

3. A laxative effect

In everyday terms, this means that sugar alcohols can make you poop. Again, this is because your stomach can’t absorb sugar alcohols, which allows them to linger in your intestines and ferment.

This effect is most common in children and adults who:

4. Weight gain

Sugar alcohols are low in calories and carbohydrates, but depending on the type, they are not free of these substances. So it’s still possible to gain weight if you eat foods containing sugar alcohols, especially if you eat too many of them.

A study of college students found that consuming high levels of dietary erythritol was associated with weight gain — specifically increased belly fat — during their freshman year.

How can you tell if a food contains sugar alcohols?

“Just as sugar hides behind different terms on food labels, sugar alcohols also have many names,” explains Bissell. If you see any of these products on a label, this is what you get:

• Xylitol is about as sweet as sugar. It comes from wheat straw and some grains. On an industrial scale it is produced from wood materials or by microbial fermentation. It is commonly found in sugar-free desserts and candies. Also commonly found in sweets for diabetes. You will also find it in some oral care products, such as toothpaste and mouthwash, because it helps prevent dental caries. The dangers associated with xylitol are related to eating it in large quantities. So it will not cause any negative effects in your dental care routine (swiss and spit).
• Erythritol is 60% to 80% as sweet as sugar. Although it can be found in small quantities in things like pears, soy sauce and watermelon, it is made on an industrial scale by yeast fermentation of corn or wheat starch. It is one of the fastest growing sugar substitutes in the food industry. Taking it as a sugar substitute can increase blood levels more than 1,000 times, and it can take days for it to return to baseline levels.
• Isomalt is about 45% to 65% as sweet as sugar. It comes from beet sugar.
• Lactitol provides about 40% of the sweetness of sugar. Manufacturers make it from milk.
• Maltitol is about 75% as sweet as sugar and is made from corn, wheat and potatoes, and catalytic hydrogenation.
• Mannitol is 50% to 70% as sweet as sugar. Naturally, it is found in carrots, olives and asparagus. Although some manufacturers make it from seaweed, much is made by the hydrogenation of fructose at high temperatures and pressure.
• Sorbitol is about half as sweet as sugar. Of course it is found in apples and pears, but industrially it is made from potato starch.

But frustratingly, you could be eating foods made with sugar alcohols without knowing it, even if you read the labels carefully. The U.S. Food and Drug Administration (FDA) does not require food companies to list sugar alcohols on their ingredient lists.

In addition to reading the ingredients on food labels, Bissell says you can identify products that may contain sugar alcohols by looking for processed foods that say they:

• Keto-safe.
• Diabetes-safe.
• Sugar-free, no sugar or little sugar.
• Artificially sweetened.
• Naturally sweetened or sweetened with natural compounds.
• Low-calorie or calorie-free.

Another piece of evidence that a product contains sugar alcohols is a label that reads, “Excessive consumption may cause a laxative effect.” The FDA requires this language on any product that contains added sorbitol or mannitol.

it comes down to

Sugar alcohols can help reduce carbohydrate intake, but the risks may be reason enough to reduce or eliminate their intake altogether. Researchers don’t yet know the full impact on your health. As with most foods, it’s best to consume products containing sugar and sugar alcohols only in moderation and focus on whole foods instead.