What Are Sugar Alcohols—And Should I Be Avoiding Them?
Experts weigh in on these sweet substitutes and whether they’re worth worrying about.
If you read the label on many dessert items promoted as “healthier” for you than the real thing—say, a pint of low-calorie ice cream versus the full-fat, full-sugar kind—you’ll likely see a few ingredients that end in “ol.” That’s a tip-off that the product contains a sugar alcohol. (Xylitol, erythritol, sorbitol and maltitol are among the most common). But, what exactly are sugar alcohols, and are they any better for you than regular sugar?
Sugar alcohols are carbohydrates that chemically have characteristics of both sugars and alcohols, according to the FDA (though it’s not the same type of alcohol found in booze). Most sugar alcohols are produced commercially and added to foods like dairy desserts, frostings, cookies, cakes, candy, and chewing gum, as a reduced-calorie sweetener.
While they’re also naturally occurring (in small amounts) in some vegetables and fruits, like berries, the biggest source of sugar alcohols for most people is processed foods, says Suzanne Dixon, a registered and licensed dietitian and epidemiologist in Portland, Oregon.
“A lot of people think [sugar alcohols] are calorie free, but they’re not,” says Dixon. They do, however, have fewer calories (1-3 per gram) than carbohydrates or protein (4 grams). While different kinds of sugar alcohols contain varying degrees of sweetness, they’re not as sweet as artificial sweeteners like aspartame (NutraSweet) or Splenda (sucralose).
It sounds like a lot of chemistry, but the major thing to know about sugar alcohols it that they don’t raise blood sugar in the same way that regular sugar (like glucose or sucrose) does, says Dixon. In fact, they first began popping up in packaged desserts labeled as “dietetic foods” in the 1970s, which essentially meant that some of the sugar in that particular item was replaced with sugar alcohols.
They can also improve the texture of foods, and interestingly, there’s also a lot of research showing the antibacterial benefits of xylitol and erythritol for oral health. For example, xylitol is often a key ingredient in toothpaste.
So why are they becoming more buzzy now? Dixon says its due to popular trends like the ketogenic diet or low-carb diet, which operate on the idea of preventing large fluctuations in your blood glucose—something sugar alcohols are great for. But growing interest in the FODMAP diet, which calls for eliminating certain carbohydrates that the small intestine doesn't digest well, has also pointed to sugar alcohols as a culprit for digestive issues like bloating, gas and loose stools.
“Most RDs are kind of neutral on sugar alcohols,” says Dixon. “There’s no evidence they’re harmful to your GI tract or microbiome, but it’s unpleasant if you’re sensitive to them.”
The bottom line: If you find yourself feeling uncomfortable after snacking on a protein bar or devouring a pint of Halo Top after dinner, you might want to avoid products with sugar alcohols. People with known IBS should also try to steer clear, as they can make symptoms worse. The average healthy person is unlikely to be consuming large amounts of them, though, says Dixon, and as such, shouldn’t worry about them at all.
“If you’re reading a lot of labels to decide what to eat,” says Dixon, “you’re already eating the wrong things.”