Sweet potatoes are often suggested as a healthier alternative to regular potatoes because of their beta-carotene content and lower glycemic index. However, sweet potatoes also contain a type of sugar called mannitol that can cause stomach pain in some sensitive people. If you have noticed that sweet potatoes hurt your stomach every time you eat them, you might have an intolerance to foods containing mannitol.
Sweet potatoes can cause gas because they contain a carbohydrate that some people have difficulty digesting, which may explain your tummy troubles with the nutritious tuber.
What Is Mannitol?
Mannitol belongs to the polyol, or sugar alcohol family. Sugar alcohols, such as sorbitol, xylitol, maltitol and mannitol, are often added to sugar-free ice cream, sugar-free candy and other sugar-free foods because they contain fewer calories and sugar compared with regular table sugar.
Some foods also naturally contain small amounts of mannitol, such as sweet potatoes, cauliflower, mushrooms, snow peas, watermelon and celery. Some people do not tolerate some types of sugar alcohols and might experience gastrointestinal problems as a result.
Polyols and Gastrointestinal Symptoms
Polyols are known to have a laxative effect when consumed in significant amounts. For most people, eating more than 10 g of sugar alcohol at once can induce diarrhea. However, some people are more sensitive to polyols and might react to even smaller amounts.
The most common symptoms of polyol sensitivity include stomach pain, abdominal bloating, cramping, flatulence, diarrhea or constipation. If your stomach hurts or if you have sweet potato intolerance symptoms over a prolonged period of time, consult your doctor because more investigation is needed to determine the source of your problem.
Watching Your Portion
If you enjoy sweet potatoes, you can still have them, but keep your portion size small. Limiting your serving of sweet potatoes to a half cup or less may help prevent undesirable symptoms. To avoid overwhelming your limited capacity to handle mannitol, avoid other mannitol-rich foods, such as watermelon, mushrooms, cauliflower, celery and snow peas, on the days you have sweet potatoes.
By controlling your intake of mannitol, you are less likely to experience pain or other gastrointestinal problems, such as diarrhea, from sweet potatoes.
If you still experience stomach problems after your doctor has ruled out other disorder that could trigger your symptoms and despite controlling your intake of mannitol, you might also react to other polyol-containing foods.
Keep a food diary with your symptoms and consult a registered dietitian to identify foods, other than sweet potatoes, that could be responsible for your symptoms. Try choosing vegetables with a lower polyol content, such as leafy greens, regular potatoes, parsnips, bok choy, green beans or bamboo shoots.
Too Much Fiber
Sweet potatoes are a good source of fiber with 5.9 grams in a large potato baked in the skin. While fiber is important for your health and essential for regular bowel movements, cholesterol and blood sugar management, too much fiber can have negative effects, especially if you suffer from gastrointestinal disorders, such as IBS or Crohn's disease. According to FamilyDoctor.org, symptoms of too much fiber in your diet may include:
- abdominal pain
- Slideshare: IBS — Free at Last: A Revolutionary, New Step-by-Step Method for Those Who Have Tried Everything. Control IBS Symptoms by Limiting FODMAPS Carbohydrates in Your Diet"; Patsy Catsos; 2009
- Hawaii Pacific Health: The Low FODMAP Diet — Reducing Poorly Absorbed Sugars to Control Gastrointestinal Symptoms"; Eastern Health Clinical School -- Monash University; 2010
- Yale New Haven Health: Eat Any Sugar Alcohol Lately?
- USDA National Nutrient Database: Sweet potato, cooked, baked in skin, flesh, without salt
- Healthline: Can You Actually Ingest Too Much Fiber?