Sugar Substitutes Cause Diarrhea

Do you ever become frustrated when you discover that something you’ve done to improve your health has caused trouble instead? Many people have encountered problems with sugar substitutes. Whether they are using them to prevent dental caries or to avoid excess pounds or increases in blood sugar. non-nutritive sweeteners can cause digestive symptoms in some people. Here are a few testimonials:

Xylitol for Dry Mouth Caused Diarrhea:

Q. The dentist recommended xylitol for my dry mouth. Wow, diarrhea city!

A. Xylitol is a sugar substitute that is frequently found in dry mouth products and sugarless gum. It can cause diarrhea.

Another reader reported that Biotène Gel was helpful for the dry mouth caused by a CPAP machine. She suffered no adverse effects. Biotene contains both sorbitol and xylitol. This suggests some people are less susceptible to GI complaints, but many other report problems.

Diarrhea from Sugar Substitutes:

Q. I am a diabetic and used to have diarrhea all the time. Then I read that sorbitol can cause diarrhea. My sugar-free pancake syrup is sweetened with sorbitol.

I stopped using it and immediately had no more diarrhea. I told my doctor about this and he agreed that sorbitol can cause diarrhea. Others may be suffering from this same problem.

A. You are not the only one to pinpoint non-sugar sweeteners as a potential cause of diarrhea.

Here is a message from another reader:

“I read a question from a reader suffering from diarrhea and stomach pain. The reader wondered if the diabetes meds were causing this.

“Was that person eating sugar-free products with the sweetener maltitol? This sweetener can also cause digestive problems. Sensitive individuals should check the list of ingredients.”

Sweeteners like sorbitol, maltitol, mannitol and xylitol are frequently used in foods for people restricting sugar. They have calories but are absorbed much more slowly than table sugar. Because they can reach the large intestine without being absorbed, they may cause diarrhea.

Other Options Less Likely to Cause Trouble:

Xylitol:

Xylitol, also known as birch sugar, is a small molecule that seems somewhat less likely to cause bloating, gas and diarrhea (International Journal of Dentistry, online Oct. 20, 2016). As noted above, some people do react badly to it. It is similar to the other sugar substitutes because it is a sugar alcohol. In this case, the term alcohol does not refer to something you drink. It is a chemical term describing the chemical structure of the compound.

Xylitol is a fermentable polyol. Consequently, people following a low-FODMAP diet need to avoid it. FODMAP stands for fermentable oligo-, di- and monosaccharides and polyols. The low-FODMAP is often recommended for the treatment of IBS.

Be very careful to keep xylitol and any xylitol-containing foods such as chewing gum, mints or peanut butter away from dogs. It is very toxic to canines.

Erythritol:

Erythritol is another sugar substitute. Many people tolerate it better than xylitol. Apparently, the microbes in our digestive tracts are not able to ferment erythritol. Some people do not develop diarrhea or stomach rumbles after consuming erythritol, although taking it with fructose could trigger those reactions. People who are sensitive to erythritol need to read labels carefully; certain brands of the sweetener stevia also contain erythritol.

Recent research has uncovered other concerns, however. People with elevated levels of erythritol in their blood are more prone to blood clots. Consequently, they are more likely to experience cardiovascular complications.

Until recently, this was based on epidemiological data. Last year, a large study found a link between high levels of erythritol in blood samples and cardiovascular complications such as strokes or heart attacks. However, correlation is not causation, so the Cleveland Clinic research team delved more deeply into the issue (Arteriosclerosis, Thrombosis, and Vascular Biology, Aug. 8, 2024).

One small study published in Arteriosclerosis, Thrombosis, and Vascular Biology demonstrated a big difference in clotting potential between people consuming 30 grams of erythritol and those consuming 30 grams of glucose. Blood levels of erythritol rose about 1,000 fold after consuming it. Every person getting the sugar substitute had an increase in the activity of blood platelets, indicating a higher propensity to form blood clots. People consuming glucose did not experience those changes. Since blood clots trigger complications like stroke, pulmonary embolism or heart attacks, this finding is worrisome.

Stevia:

Another sweetener that is becoming popular, steviol, does not appear to cause diarrhea or other difficulties often (Current Pharmaceutical Design, online Oct. 21, 2016). Stevia is derived from a South American plant, Stevia rebaudiana. Steviol might act as an endocrine disrupter at high doses, however (Molecular and Cellular Endocrinology, May 15, 2016). In general, non-sugar sweeteners are linked to increased inflammation. As a result, you might want to moderate your consumption of any sugar substitutes so that you eat only the minimum needed to make food palatable.

Don’t Count Too Much on Sugar Substitutes:

An analysis of randomized trials found “no to minimal benefit” in switching to non-nutritive sweeteners for long-term weight control (Endocrine Practice, Oct. 2021). Use for dry mouth or to protect teeth from cavities might not always require long-term use. There are hints that some sugar substitutes can change the balance of microbes in the digestive tract towards a more inflammatory pattern.