Can potatoes cause stomach issues? A complete guide to digestive troubles

October 11, 2025 •

4 min read

For most people, potatoes are a well-tolerated staple, but for some, a meal containing them can trigger digestive distress. This versatile vegetable, a nutritional powerhouse rich in potassium and vitamin C, sometimes comes with hidden gastrointestinal drawbacks. We delve into the reasons why can potatoes cause stomach issues and how you can enjoy them with minimal discomfort.

Quick Summary

Potatoes can cause digestive problems due to allergies, intolerances, and natural toxins like solanine found in green or sprouted parts. High fiber and resistant starch content can also lead to gas and bloating, especially in sensitive individuals.

Key Points

Allergies vs. Intolerances: Potato allergies involve an immune response, while intolerances are limited to digestive issues like gas and bloating.
Avoid Green or Sprouted Potatoes: Green spots and sprouts indicate higher levels of the toxin solanine, which can cause severe digestive and neurological symptoms.
Understand Resistant Starch: Cooked and cooled potatoes have higher levels of resistant starch, which is a prebiotic fermented by gut bacteria, but can cause gas and bloating in sensitive people.
Proper Cooking Deactivates Lectins: Thoroughly cooking potatoes, especially boiling, deactivates most of the lectins that can potentially cause gut inflammation.
Adjust Intake and Preparation: For sensitive digestion, peel potatoes, cook them thoroughly, and start with small portions to gauge tolerance. This also helps manage fiber intake, which can cause issues in large amounts.
Regular Potatoes Are Generally Low FODMAP: For those with Irritable Bowel Syndrome (IBS), regular potatoes are a low FODMAP option, unlike sweet potatoes, which are limited.

What Makes Potatoes Hard to Digest for Some?

While potatoes are a global food staple, certain compounds and individual sensitivities can lead to stomach upset. Understanding these potential culprits is the first step toward enjoying potatoes without the discomfort.

Allergies and Intolerances: A Matter of Immunity and Digestion

One of the most common reasons people experience digestive issues from potatoes is an allergy or intolerance. It's crucial to distinguish between the two:

Food Allergy (Immune Response): A true potato allergy involves the immune system, which mistakenly identifies proteins like patatin as harmful invaders. This triggers an immune response, releasing antibodies that can cause a range of symptoms, including hives, swelling, or respiratory issues, in addition to digestive upset like diarrhea and vomiting.
Food Intolerance (Digestive Response): Much more common than an allergy, an intolerance involves the digestive system, not the immune system. This can result from enzyme deficiencies or a sensitivity to a naturally occurring chemical in the potato. Symptoms are typically less severe than an allergy and are often limited to gastrointestinal distress, such as bloating, gas, nausea, and diarrhea.

Solanine: The Natural Toxin in Green Potatoes

Potatoes are part of the nightshade family, which naturally produces toxic compounds called glycoalkaloids, primarily solanine. In most commercially available potatoes, the levels are too low to be harmful. However, exposure to light or damage can increase solanine production, which is often indicated by a green tint on the skin and a bitter taste. Consuming potatoes with high levels of solanine can cause:

Nausea and vomiting
Abdominal pain and stomach cramps
Diarrhea
Burning sensation in the throat or mouth

To avoid this, always store potatoes in a cool, dark place. If a potato has green spots or sprouts, they should be removed. If it tastes bitter, it's best to discard it entirely.

Resistant Starch: A Prebiotic with Potential Side Effects

Potatoes contain a type of carbohydrate called resistant starch, which isn't digested in the small intestine but instead ferments in the large intestine. This fermentation is beneficial for gut bacteria but can cause discomfort for some, especially when first introduced to the diet or consumed in large quantities. Gas and bloating are common side effects. Interestingly, cooking and then cooling potatoes (e.g., in a potato salad) increases the amount of resistant starch, which can be both a benefit and a potential issue for those with sensitive digestion.

Lectins: Plant Proteins That Can Cause Trouble

Lectins are proteins found in many plants, including potatoes, that serve as a natural defense mechanism. Some research suggests that active lectins can interfere with nutrient absorption and cause inflammation in the gut lining. However, this is a topic of debate, and the good news is that cooking, particularly boiling or baking, can largely deactivate lectins, rendering them harmless for most people. The highest concentration of lectins is found in the potato skin, so peeling may help individuals with extreme sensitivity.

How to Minimize Digestive Issues from Potatoes

If you love potatoes but find they sometimes upset your stomach, a few simple adjustments can make a big difference.

Choose the Right Cooking Method: While all cooking methods help deactivate lectins, boiling and cooling potatoes is particularly beneficial. This increases the resistant starch content, which is good for gut health in moderation, but can be a double-edged sword for the extremely sensitive. For a less fermentable option, serve them hot right after cooking. Steaming or baking are also gentle on the stomach.
Peel Them: Many of the potentially problematic compounds like solanine and lectins are concentrated in the skin. For sensitive individuals, simply peeling the potato can significantly reduce the risk of digestive upset.
Monitor Portion Size: Large quantities of any food can cause digestive strain. Pay attention to your body's response and scale back your potato portion if you experience discomfort.
Pair with Other Foods: Serving potatoes with a source of protein and some non-starchy vegetables can help slow digestion and prevent potential discomfort.
Check for Sprouting or Green Tints: Always inspect your potatoes for signs of spoilage. Green or sprouted parts should be removed completely.

Comparison of Potato-Related Digestive Issues


Cause	Mechanism	Key Symptoms	Mitigation Strategy
Allergy	Immune system identifies protein (patatin) as threat, releases antibodies.	Hives, swelling, respiratory issues, severe digestive upset.	Avoid potatoes completely.
Intolerance	Digestive system lacks enzymes or is sensitive to a compound.	Bloating, gas, nausea, diarrhea.	Reduce portion size; modify preparation.
Solanine Toxicity	Ingestion of glycoalkaloids from green or sprouted parts.	Nausea, vomiting, abdominal pain, burning throat sensation.	Discard green/bitter potatoes; store properly.
Resistant Starch	Beneficial gut bacteria ferment undigested starch.	Gas, bloating, stomach discomfort.	Increase intake gradually; serve potatoes hot.
Lectins	Plant proteins resist digestion, potentially causing inflammation.	Varies, potentially linked to joint pain or gut inflammation.	Cook thoroughly (especially boiling); peel potatoes.

Conclusion

While potatoes are a nutritious and versatile food, they are not without potential digestive downsides for certain individuals. Problems range from rare allergies to more common intolerances, high fiber intake, or the presence of natural compounds like solanine, lectins, and resistant starch. Fortunately, most of these issues can be managed by paying attention to potato quality, preparation methods, and portion control. By cooking potatoes thoroughly, peeling them if you are sensitive, and introducing high-resistant-starch preparations slowly, you can often enjoy this staple without suffering the stomach issues. If persistent problems arise, it may be a sign of a more serious intolerance or allergy, and it's best to consult a healthcare professional for guidance. For more insights on nightshade sensitivity, visit the UC Davis Health blog.

Frequently Asked Questions

Yes, for some individuals, the resistant starch in potatoes, especially when cooked and cooled, can cause bloating and gas. This is because it ferments in the large intestine, feeding gut bacteria and producing gas.

No, white potatoes are generally considered a low-FODMAP food, even in generous portions. However, sweet potatoes are only low-FODMAP in smaller, limited servings.

A potato allergy triggers an immune system response with symptoms like hives, swelling, or severe digestive issues. An intolerance is a milder, digestive-only reaction with symptoms like gas, bloating, or diarrhea.

Solanine is a toxic compound found in nightshade plants like potatoes. Levels increase when potatoes are exposed to light, causing them to turn green. High amounts can cause nausea, vomiting, and abdominal pain.

Yes, peeling a potato can be helpful. The skin contains higher concentrations of lectins and solanine. Removing it can reduce exposure to these compounds for sensitive individuals.

Yes, some individuals have a sensitivity to nightshade vegetables, which include potatoes. This can cause digestive discomfort and potentially worsen joint pain for those with inflammatory conditions.

Boiling, steaming, or baking potatoes until tender can help make them easier to digest. Cooking them thoroughly deactivates lectins. Peeling the skin also helps, and serving them hot reduces the amount of resistant starch compared to serving them cold.