When it comes to sugar substitutes, there seems to be an endless array of difficult-to-pronounce items and even more opinions on their health benefits, safety, or undiscovered toxic effects. So today, I’m going to tackle just one category of sugar substitutes—sugar alcohols. When I talk about sugar, I mean refined table sugar or sucrose. You know...the white stuff that we all love. But the fear of weight gain from eating sugar is always hanging over our heads. So instead, sometimes we turn to sugar substitutes like sugar alcohols.
What are they?
Sugar alcohols or (polyols) are carbohydrates found naturally in some plant foods, or are manufactured from other carbohydrate sources (such as corn, sugar beets, or whey) by adding hydrogens to sugars from those sources. They have less absorbable calories than sugar, and thus are seen as a great sugar substitute. So you can get a sweet taste with less calories.
Some common sugar alcohols include:
- Sorbitol
- Mannitol
- Xylitol
- Erythritol
- Isomalt
- Lactitol
The major benefit of sugar alcohols actually is their poor metabolism or digestibility. Because they’re not easily digested and are typically poorly absorbed through passive diffusion, they only have (on average) 2 calories per gram instead of the 4 found in table sugar. They also don’t cause a large rise in blood sugars or insulin, like sugar does. However, this perceived benefit can have negative side effects, too. Since large portions aren’t digested, they travel to the large intestine where they ferment causing gas build up, and attract water, which can lead to diarrhea. So in large amounts, they can cause some pretty serious GI distress. Erythritol is the exception to this, as it’s absorbed in the small intestine and excreted, unchanged, through our urine1.
Are they safe?
As a dietitian, I’m often asked about the safety of sugar-free or diet foods. My answer is always, “I’m not 100% sure.” The FDA has labeled them as GRAS (Generally Recognized As Safe), and, as far as we know, the answer is yes. However, could there be negative side effects we’re not aware of? Yep.
As frustrating as it is, nutrition and health is an ever-evolving field. We’re always studying and learning to better understand, prevent, treat, and improve. So I can’t guarantee that sugar substitutes are 100% safe, but I can tell you that as far as the clinical data sits, for now they appear to be. In my opinion, moderate amounts will likely pose no harm. So if you’d like to enjoy low-sugar desserts or sugar-free chewing gum, do so in moderation. If you don’t trust these products, have sugary desserts and gum in moderation. Remember, when it comes to nutrition, it’s the dosage that makes it a poison or a medicine!
Megan Ostler MS, RDN
iFit Dietitian
- Arrigoni, Eva, Fred Brouns, and Renato Amado. "Human Gut Microbiota Does Not Ferment Erythritol." British Journal Of Nutrition 94 (2005): 643-46. Research Gate. Web. 30 June 2016.
WARNING: This post is not intended to replace the advice of a medical professional. The above information should not be used to diagnose, treat, or prevent any disease or medical condition. Please consult your doctor before making any changes to your diet, sleep methods, daily activity, or fitness routine. iFit assumes no responsibility for any personal injury or damage sustained by any recommendations, opinions, or advice given in this article.
