What are Polyols?

If you’re following a low FODMAP diet for Irritable Bowel Syndrome (IBS), you’ve probably heard of polyols—but don’t be fooled by their name. These sugar alcohols won’t make you drunk! Instead, they’re a group of sneaky FODMAPs that can cause significant digestive discomfort for some people.

Polyols can be naturally found in fruits and vegetables or artificially added to processed foods as low-calorie sweeteners. This is why you’ll often see them in products like sugar-free gum, diabetic sweets, protein bars, and diet-friendly snacks.

Unfortunately, for many people with IBS, polyols can lead to symptoms like bloating, gas, abdominal pain, and diarrhoea. That’s why it’s important to know where they hide—and how to spot them. While on the first phase of low FODMAP diet, you should look out for six polyols: sorbitol (420), mannitol (421), maltitol (965), xylitol (967), isomalt (953), and lactitol (966) (1).

Let’s take a closer look.

How do polyols cause gut issues?

Only one-third of the polyols consumed are actually absorbed in the small intestine. The level of absorption depends on the type of polyol and the individual. The rest of the polyols travel down to the large intestine, where gut bacteria use them as food and ferment them. This fermentation produces gas and draws in water, leading to bloating, cramps, and changes in bowel habits (2, 3).

Because of this effect, polyols are known to have a natural laxative effect (2, 3). If you’ve ever seen a warning on a pack of sugar-free gum saying “excess consumption may cause a laxative effect,” it’s thanks to polyols!

Common Polyols To Watch Out For

When you’re on the low FODMAP diet, it’s best to avoid these six high FODMAP sugar alcohols during the first phase of the low FODMAP diet:

1. Sorbitol (420)
2. Mannitol (421)
3. Maltitol (965)
4. Lactitol (966)
5. Xylitol (967)
6. Isomalt (953)

You’ll often find them listed on ingredient labels either by name or by their food additive numbers (shown in brackets). Be extra cautious with anything labelled sugar-free, low-carb, or diabetic-friendly, as these often contain polyols.

Where are polyols found?

Polyols naturally occur in many fruits and vegetables, but they’re also manmade and added to processed products:

• Sugar-free gums and mints
• Protein bars and meal replacements
• Ice creams and frozen desserts
• Cough drops and throat lozenges
• Baked goods
• Diabetic-friendly or low-sugar products
• Chocolate and candy

If you’re following a low FODMAP diet, always read labels carefully. Look out not only for the polyol names but also their additive numbers, which are used in ingredient lists, especially outside the United States.

What are the different sugar alcohols?

Sorbitol (420)

Sorbitol tends to be commonly found in fruits like apples, apricots, cherries, nectarines, peaches, pears, plums, and prunes (2 3). Sorbitol is also manufactured and used as an artificial sweetener because it has approximately 60% of the sweetness of sucrose (table sugar) (4). Check processed products for 420 or glucitol, as these are other names for sorbitol (2, 4).

Mannitol (421)

Mannitol naturally occurs in a range of fruits and vegetables, such as watermelon, celery, and mushrooms (3). Mannitol can also be manufactured from fructose sourced from cornstarch. Check processed products for mannitol food additive number 421 (6).

Maltitol (965)

Maltitol is another poorly absorbed sugar alcohol. It is also an ideal sweetener for food products, as it is 90% as sweet as sugar, making it a highly attractive sugar replacement (5). Its food additive number is 965 (6).

Lactitol (966)

Lactitol is a sugar alcohol derived from lactose-rich whey. It is commonly used in chewing gum, hard and soft candies, and frozen dairy desserts and is often mixed with other artificial sweeteners (9). Watch out for the food additive number 966 (6).

Xylitol (967)

Low levels of xylitol naturally occur in fruits, vegetables, and other plants (8). Xylitol can be commercially extracted from corncobs and hardwood trees. During the first phase of the low FODMAP diet it needs to be avoided when it is used as an artificial sweetener. When checking labels watch out for Xylitol, birch sugar, or 967 (10).

Isomalt (953)

Isomalt definitely does not end in ‘ol’ which means it is easy to miss it when reading labels. Isomalt is a sugar alcohol that contains both sorbitol and mannitol, which is why it is high FODMAP and should be avoided in the low FODMAP phase.

During the manufacturing process of isomalt, the fructose portion of cane sugar is converted into two disaccharides: glucose-sorbitol (gluco-sorbitol) and glucose-mannitol (gluco-mannitol) (7). Watch out for isomalt’s food additive number 953 when checking food labels (6).

Erythritol (968)

Erythritol is relatively well absorbed in our small intestines when compared to the other high FODMAP sugar alcohols (11). However, it is still recommended to avoid erythritol until you have finished the FODMAP reintroduction phase. Then you can test your tolerance to it.

Final Thoughts

Polyols are a common trigger for IBS symptoms and are classified as high FODMAP. While they can be tricky to spot, understanding their sources and names can help you steer clear during the low FODMAP phase. The good news? You don’t have to avoid them forever!

Once your symptoms are under control, you can test each polyol individually during the reintroduction phase to see which ones your body can handle. Everyone’s tolerance is different, so take your time, go slow, and listen to your gut

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