What are Sugar Alcohols (Polyols)?
Despite their name, sugar alcohols are not sugars or alcoholic beverages. They are a type of carbohydrate with a chemical structure similar to sugar and are also known as polyols. They provide a sweet taste but with fewer calories because the body does not fully absorb them. Instead, most of the unabsorbed polyol travels to the large intestine where it can be fermented by gut bacteria. This process is what can cause uncomfortable gastrointestinal symptoms for individuals with Irritable Bowel Syndrome (IBS), as sugar alcohols are the 'P' in the FODMAP acronym.
The Link Between Polyols and Digestive Symptoms
When polyols reach the large intestine, gut bacteria rapidly ferment them, producing gas that can cause bloating and abdominal pain. In addition, many polyols have an osmotic effect, meaning they draw water into the large intestine, which can lead to diarrhea. The severity of these symptoms depends on the amount consumed, the specific type of polyol, and an individual's unique sensitivity.
High FODMAP Sugar Alcohols to Avoid
During the elimination phase of the low FODMAP diet, it is recommended to avoid certain sugar alcohols, which are common culprits for digestive distress.
- Sorbitol (E420): Found naturally in stone fruits, apples, pears, and blackberries, it is also widely used as an artificial sweetener in sugar-free products like gum, candy, and diet foods.
- Mannitol (E421): Occurs naturally in foods like mushrooms, cauliflower, and watermelon. It is also added to many processed foods.
- Xylitol (E967): Derived from corn cobs and hardwood trees for commercial use, it is a frequent ingredient in sugar-free gum, mints, and some dental products.
- Maltitol (E965): Often used in sugar-free chocolates and baked goods, its absorption is incomplete, leading to potential GI issues.
- Isomalt (E953): A blend of two sugar alcohols, isomalt also has a high FODMAP content and should be avoided.
- Lactitol (E966): Derived from lactose, this polyol is also high in FODMAPs.
The Low FODMAP Sugar Alcohol Exception: Erythritol
Erythritol (E968) is the one major sugar alcohol that is generally considered low FODMAP and safe for consumption during the elimination phase. Unlike other polyols, erythritol is much smaller and is absorbed more efficiently in the small intestine before it can reach the large intestine for fermentation. For this reason, it is far less likely to cause digestive symptoms. However, individual tolerance can vary, and some may still experience issues with very large quantities. It is often used in keto-friendly and low-calorie packaged foods. For further guidance on low FODMAP sweeteners, consult the Monash University FODMAP blog.
Comparison of High vs. Low FODMAP Polyols
| Feature | High FODMAP Polyols (Sorbitol, Mannitol, Xylitol) | Low FODMAP Polyol (Erythritol) |
|---|---|---|
| Absorption Rate | Poorly absorbed in the small intestine | Efficiently absorbed in the small intestine |
| Fermentation | Rapidly fermented by gut bacteria in the large intestine | Minimal fermentation due to high absorption |
| Digestive Symptoms | Likely to cause gas, bloating, and diarrhea, especially in sensitive individuals | Generally well-tolerated with minimal digestive issues at typical doses |
| FODMAP Status | High FODMAP | Low FODMAP |
| Common Sources | Stone fruits, mushrooms, sugar-free gum, candy | Primarily added to sugar-free and keto products |
How to Identify and Avoid High FODMAP Sugar Alcohols
Because sugar alcohols are hidden in many "sugar-free" or "diet" products, it is crucial to become a diligent label reader. Look for ingredients that end in "-ol," such as sorbitol, xylitol, and mannitol. Additionally, some polyols are identified by E-numbers, such as E420 (Sorbitol), E421 (Mannitol), E967 (Xylitol), and E953 (Isomalt). Many sugar-free gums, mints, cough lozenges, and keto products contain high FODMAP polyols.
Low FODMAP Alternatives for Sweetening
For those seeking low FODMAP sweeteners, several alternatives can be used with caution and in appropriate serving sizes:
- Table Sugar (Sucrose): Monash University tests show that table sugar has a low FODMAP threshold.
- Maple Syrup: A popular low FODMAP choice in moderate servings.
- Rice Malt Syrup: Another syrup option that is low FODMAP.
- Stevia and Monk Fruit: These are generally considered low FODMAP, but check labels for high FODMAP additives like inulin.
Conclusion
In summary, the statement "Is sugar alcohol high in FODMAP?" is not a simple yes or no answer. Most sugar alcohols, or polyols, including sorbitol, mannitol, xylitol, and maltitol, are indeed high in FODMAPs and should be avoided by sensitive individuals during the elimination phase of the low FODMAP diet. However, the key exception is erythritol, which is well-absorbed and generally well-tolerated, making it a suitable option for low FODMAP use. Becoming aware of these differences and reading product labels carefully is essential for managing IBS symptoms and maintaining digestive comfort.
