Nutrition Diet: What are three ways to reduce the gas caused by eating legumes?

October 30, 2025 •

4 min read

Legumes are a highly nutritious source of fiber and plant-based protein, but a survey showed many people limit their intake due to uncomfortable gas and bloating. Fortunately, there are effective methods to address this common issue. Here are what are three ways to reduce the gas caused by eating legumes and several other practical techniques to boost your digestive comfort.

Quick Summary

Gas and bloating from legumes are primarily caused by fermentable fibers and complex carbohydrates called oligosaccharides. Strategic preparation methods, gradual consumption, and enzyme supplements are key to minimizing digestive discomfort and enjoying these nutrient-dense foods.

Key Points

Soak and Rinse Legumes: Discard soaking water from dried beans and rinse canned legumes to wash away some gas-producing oligosaccharides.
Gradual Intake: Start with small portions of legumes and increase your consumption slowly to allow your gut bacteria time to adapt to the added fiber.
Use Digestive Enzymes: Take alpha-galactosidase supplements, like Beano, right before eating to help your body break down the complex sugars that cause gas.
Cook Thoroughly: Ensure beans are cooked completely until very soft, as proper cooking helps to break down gas-causing compounds.
Stay Hydrated: Drink plenty of water throughout the day to help your digestive system process the extra fiber from legumes more smoothly.
Incorporate Digestive Aids: Consider adding spices like epazote or asafoetida, or even a little baking soda during preparation, to aid digestion.

Legumes, such as beans, lentils, and peas, are nutritional powerhouses rich in fiber, protein, and essential minerals. However, they contain certain compounds that can lead to intestinal gas and bloating for some people. The primary culprits are oligosaccharides, which are complex carbohydrates, and high amounts of soluble fiber. The human digestive system lacks the necessary enzymes to fully break down these compounds in the small intestine. They travel to the large intestine where gut bacteria ferment them, producing gases like methane, carbon dioxide, and hydrogen. While this is a sign of a healthy, active gut microbiome, the resulting symptoms can be bothersome. Fortunately, several simple strategies can make legumes much easier to digest.

The Three Primary Methods to Reduce Legume Gas

Method 1: Soaking and Rinsing

One of the most effective strategies for reducing gas from legumes is proper preparation through soaking and rinsing. This process helps to remove some of the water-soluble, gas-producing oligosaccharides. For dried legumes, a long soak is best. Place the legumes in a large bowl and cover them with several inches of water. Some experts recommend soaking for 8 to 12 hours, while others suggest an even longer period of up to 48 hours, changing the water every few hours to maximize the removal of sugars. For an even quicker method, you can do a “quick soak” by bringing the legumes to a boil in water for a few minutes, then letting them stand for an hour before draining. For canned beans, a simple and crucial step is to drain the liquid and rinse them thoroughly with fresh water. This flushes away the oligosaccharides that have leached into the canning water and also reduces excess sodium.

Method 2: Gradual Acclimation

If your body is not accustomed to a high-fiber diet, introducing legumes too quickly can overwhelm your gut bacteria and lead to increased gas. The solution is to add them to your diet slowly, giving your digestive system time to adjust. A study found that individuals who gradually incorporated legumes into their diet experienced less gas and bloating over time as their gut microbiome adapted. Start with small portions, such as a few tablespoons a day, and slowly increase the amount over several weeks. Combining legumes with other, easier-to-digest foods can also help. This gradual approach allows the gut bacteria population that can process the legumes more efficiently to grow, leading to reduced symptoms.

Method 3: Digestive Enzyme Supplements

For those who need an extra boost, over-the-counter digestive enzyme supplements can be highly effective at preventing gas before it starts. Products containing the enzyme alpha-galactosidase, such as Beano, work by helping your body break down the complex carbohydrates in gassy foods. These supplements are taken just before or during the first bite of a meal containing legumes. The enzyme works in the stomach to break down the oligosaccharides before they reach the colon and are fermented by bacteria. This method offers a straightforward way to enjoy a wide variety of legumes and other gas-causing foods without discomfort, regardless of your gut's current level of adaptation.

Beyond the Basics: Other Helpful Techniques

Additional Preparation Tricks

Add Baking Soda: A small amount of baking soda added to the soaking water can help break down some of the gas-producing sugars, further enhancing the soaking method's effectiveness.
Use Spices: Certain traditional spices, such as epazote (common in Mexican cooking), asafoetida (hing, used in Indian cuisine), or even cumin and fennel, are known to aid digestion and can be added during the cooking process to help reduce gas.

Cooking and Eating Habits

Cook Thoroughly: Making sure legumes are cooked until they are very soft can help break down their complex sugars and make them easier to digest.
Stay Hydrated: Drinking plenty of water when consuming high-fiber foods is essential. Water helps move the fiber through your digestive system smoothly, preventing constipation and related discomfort.
Chew Thoroughly: The digestive process begins in the mouth. Chewing your food well helps break down legumes into smaller, more manageable pieces, which eases the burden on your digestive system.

Legume Preparation Comparison Table


Feature	Dried Legumes	Canned Legumes
Preparation Time	Requires significantly more time due to soaking and cooking.	Minimal preparation; just drain and rinse.
Control over Ingredients	Full control over seasoning and liquid; can avoid additives like salt.	Ingredients may include added sodium and preservatives.
Effect on Gas	Soaking and rinsing effectively reduces oligosaccharides before cooking.	Rinsing removes a portion of the gas-causing compounds that have leached into the canning liquid.
Nutrient Content	Can be slightly higher in certain nutrients depending on the preparation.	Similar nutritional value, though some nutrients may be lost in the liquid.
Flavor	Often provides a richer, fresher flavor profile.	Flavor is generally milder and may require more seasoning.

Conclusion

Don't let the fear of gas prevent you from enjoying the immense nutritional benefits of legumes. By implementing strategies such as proper soaking and rinsing, gradually increasing your intake, and using digestive enzyme supplements when necessary, you can enjoy these versatile foods with confidence. Combining these key methods with thorough cooking, adequate hydration, and conscious eating will make a significant difference in your digestive comfort, allowing you to fully embrace legumes as a healthy and delicious part of your diet.

The Bean Institute provides additional tips on gas reduction

Frequently Asked Questions

Legumes cause gas and bloating primarily due to high levels of soluble fiber and complex carbohydrates called oligosaccharides, particularly raffinose. The human body lacks the enzymes to break down these compounds in the small intestine, so they pass to the large intestine, where gut bacteria ferment them and produce gas.

Yes, soaking dried beans helps reduce gas. Since the gas-causing sugars are water-soluble, they leach into the soaking water. Discarding the soaking water and cooking the beans in fresh water removes a significant portion of these compounds, making the legumes more digestible.

For effective gas reduction, soak dried beans for at least 8 to 12 hours. For an even greater effect, you can soak them for 24 to 48 hours, remembering to change the water multiple times to discard more of the oligosaccharides.

Supplements containing alpha-galactosidase, like Beano, are effective for most people because they provide the enzyme needed to break down the complex sugars in legumes before they cause gas. However, individual reactions vary, so what works for one person may not completely eliminate gas for another.

To reduce gas from canned beans, always drain the canning liquid and rinse the beans thoroughly under cold running water for at least a minute. This flushes away the oligosaccharides that leach into the liquid during the canning process, and also reduces the sodium content.

Yes, smaller legumes like red lentils and split peas tend to be easier to digest and less gassy because they have a lower concentration of complex sugars and are broken down more easily during cooking. Larger beans, such as kidney and pinto beans, often cause more gas.

Yes. Using a pressure cooker can help break down gas-causing compounds more quickly than traditional stovetop cooking. Additionally, incorporating certain spices like epazote or asafoetida during cooking has been anecdotally shown to aid digestion.