Can Pulses Upset Your Stomach? Why It Happens and What to Do

November 30, 2025 •

4 min read

According to the Food and Agriculture Organization of the United Nations, pulses have been a human food staple for over 8,000 years. But even with this long history, many people wonder, "Can pulses upset your stomach?" The answer is yes, though this common digestive issue can be easily managed with the right preparation and dietary practices.

Quick Summary

Digestive discomfort from pulses stems from indigestible carbohydrates like raffinose and high fiber content. Proper soaking, cooking, and gradual introduction can help your body adapt and prevent gas or bloating. Understanding your gut's reaction is key.

Key Points

Oligosaccharides Cause Gas: Complex sugars like raffinose in pulses ferment in the large intestine, producing gas and leading to bloating.
High Fiber Content: A sudden increase in the high fiber found in pulses can temporarily cause digestive discomfort and gas as your gut adapts.
Soak Dried Pulses: Soaking overnight and discarding the water is a proven method for reducing the levels of oligosaccharides and phytic acid.
Cook Thoroughly: Proper, slow cooking and rinsing canned pulses also significantly improve digestibility and reduce gas-causing compounds.
Start Small and Add Spices: Begin with small portions and incorporate digestive spices like cumin and ginger to ease your body into accepting pulses.
Symptoms Usually Subside: Most people find that their digestive system adapts to regular pulse consumption over a few weeks, and discomfort decreases.
Listen to Your Body: If you have a digestive condition like IBS or IBD, or experience severe symptoms, consult a healthcare professional for guidance.

The Science Behind Pulses and Digestive Discomfort

Pulses are the edible seeds of legume plants and include items like lentils, chickpeas, and beans. While a nutritional powerhouse, their rich composition can sometimes lead to an upset stomach. The primary culprits are two types of carbohydrates that are difficult for the human digestive system to break down completely: oligosaccharides and high fiber content.

Oligosaccharides: The Gas-Causing Sugars

One of the main reasons pulses can cause gas and bloating is the presence of oligosaccharides, specifically raffinose and stachyose. These are complex sugars that humans lack the enzyme (alpha-galactosidase) to properly digest in the small intestine. As a result, they travel to the large intestine largely intact, where they are fermented by gut bacteria. This fermentation process produces gases like hydrogen, carbon dioxide, and methane, which lead to bloating, cramps, and flatulence.

Raffinose: A type of sugar found in beans, broccoli, cabbage, and other legumes.
Stachyose: Similar to raffinose, this is another complex sugar that contributes to gas production.

High Fiber Content: The Double-Edged Sword

Pulses are an excellent source of dietary fiber, which is crucial for gut health, but a sudden increase in fiber intake can overwhelm your digestive system. The beneficial bacteria in your colon ferment this fiber, producing gas as a byproduct. While your gut microbiota will adapt over time, a rapid shift in diet can cause temporary discomfort. For most people, this is a sign that their digestive system is working as it should.

Practical Ways to Reduce Digestive Issues from Pulses

Fortunately, you don't have to give up on pulses to avoid an upset stomach. Many traditional preparation methods and dietary adjustments can significantly reduce their gas-producing properties.

The Importance of Soaking

Soaking dried pulses before cooking is a time-tested technique for a reason. It helps to dissolve and remove some of the indigestible oligosaccharides and phytic acid, making the pulses easier on your gut.

Overnight Soak: For best results, soak dried beans or lentils for at least 12 hours, or even up to 24 hours, changing the water frequently.
Discard Water: Always discard the soaking water. Never cook the pulses in the same water they were soaked in, as it will contain the very compounds you are trying to remove.

The Right Cooking Methods

How you cook pulses also plays a vital role in their digestibility. Thorough, slow cooking helps to break down complex fibers and heat-sensitive lectins that can interfere with nutrient absorption.

Slow and Low: Cook pulses over low heat for a longer duration to break down hard-to-digest fibers.
Rinse Canned Pulses: For canned varieties, drain the liquid and rinse them well under running water. The canning liquid often contains leached oligosaccharides.

Dietary Adjustments and Add-ins

Incorporating other ingredients and slowly increasing your pulse intake can also help your body adjust.

Start Small: If you are new to eating pulses regularly, introduce them gradually into your diet. Start with small portions, like a couple of tablespoons per meal, and increase as your body adapts.
Add Digestive Spices: Certain spices and herbs can aid digestion. Adding carminative spices like cumin, fennel, coriander, ginger, and asafoetida (hing) during cooking can help reduce gas.
Consider Enzymes: Over-the-counter enzyme supplements, such as alpha-galactosidase, can help break down the gas-causing oligosaccharides before they reach the colon.

Comparison of Preparation Methods for Digestibility


Preparation Method	Reduces Oligosaccharides	Improves Digestibility	Notes
Soaking (Dried Pulses)	High	Very High	Discarding soaking water is crucial to wash away gas-causing compounds.
Cooking Thoroughly	High	High	Slow, long cooking breaks down tough fibers and anti-nutrients.
Rinsing Canned Pulses	High	High	Drains away oligosaccharides that have leached into the liquid.
Sprouting	Very High	Very High	Activates enzymes that break down complex sugars further.
Gradual Introduction	Not Applicable	High	Allows your gut microbiome time to adjust to increased fiber intake.

Potential Health Concerns Beyond Temporary Discomfort

While temporary bloating and gas are normal, persistent or severe symptoms could indicate an underlying issue. Individuals with conditions like Irritable Bowel Syndrome (IBS) or Inflammatory Bowel Disease (IBD) may have heightened sensitivity to pulses. In these cases, it is especially important to start with smaller, more manageable portions and consult a healthcare professional or registered dietitian for personalized advice. In rare cases, severe reactions could point to food sensitivities that require further investigation.

Conclusion: Enjoying Pulses Comfortably

In conclusion, pulses are a highly nutritious part of a healthy diet, rich in fiber and protein, and beneficial for gut health. While they can cause temporary digestive upset, such as gas and bloating, this is often a sign of a healthy digestive system at work. By implementing simple yet effective preparation techniques like soaking, proper cooking, and gradually introducing them into your diet, most individuals can enjoy the many health benefits of pulses without discomfort. Listen to your body, and if you have persistent or severe symptoms, seek professional medical guidance. The minor adjustments needed to improve digestibility are a small price to pay for the significant nutritional rewards. Learn more about the specific compounds that make pulses tricky to digest in this review of pulse crop constituents from the National Institutes of Health.

Frequently Asked Questions

The primary cause is the presence of oligosaccharides, complex sugars that the human body cannot fully digest. Gut bacteria ferment these sugars in the large intestine, producing gas that causes bloating.

Yes, soaking dried pulses overnight and discarding the water is a highly effective way to reduce oligosaccharides and phytic acid, making them easier to digest.

Yes, smaller and split pulses like red lentils tend to be easier to digest for some people than larger beans like chickpeas or kidney beans. Canned and rinsed pulses are also often gentler on the stomach.

Adding digestive spices like cumin, ginger, fennel, and asafoetida (hing) during cooking can help to ease digestion and reduce the symptoms of gas and bloating.

Canned pulses have been pre-soaked and cooked, and the oligosaccharides have often leached into the canning liquid. Rinsing the pulses thoroughly removes this liquid and reduces the gas-causing compounds.

Yes, introducing pulses gradually, starting with small portions, allows your gut bacteria to adapt to the increased fiber intake, minimizing temporary gas and bloating.

Individuals with conditions like IBS or IBD may be more sensitive to pulses. It's best to consult a healthcare professional or dietitian for personalized guidance on how to incorporate them into your diet safely.