Is it difficult to digest beans? How to make them easier on your stomach

November 15, 2025 •

4 min read

According to a study published in Nutrients, most people's bodies can adjust to the fiber in beans over time, but for some, the initial experience can be uncomfortable. While beans are incredibly nutritious, rich in protein and fiber, many people find it difficult to digest beans, leading to unpleasant side effects like gas and bloating.

Quick Summary

Beans are sometimes hard to digest due to complex carbohydrates like oligosaccharides, which ferment in the large intestine. Proper preparation, including soaking, rinsing, and cooking thoroughly, can significantly improve digestibility and reduce gas and bloating. Acclimating your digestive system with a slow and gradual introduction to beans also helps minimize discomfort.

Key Points

Oligosaccharides are the Culprit: The main reason beans cause gas and bloating is due to complex sugars called oligosaccharides, which our bodies can't fully digest, leading to fermentation by gut bacteria in the colon.
Preparation is Key: Soaking dried beans overnight, thoroughly rinsing all beans (dried or canned), and cooking them completely can significantly reduce the amount of gas-producing compounds.
Choose the Right Beans: Smaller, sweeter beans and legumes like red and yellow lentils, mung beans, and black-eyed peas are generally easier to digest than larger, tougher varieties such as kidney beans and navy beans.
Introduce Beans Gradually: Start with small portions and slowly increase your intake over several weeks to allow your gut microbiome to adapt to the higher fiber content, which can help reduce discomfort over time.
Use Cooking Aids: Adding spices like cumin or fennel, or a strip of kombu (seaweed), to the cooking water can help break down some of the indigestible sugars.
Consider Digestive Enzymes: Over-the-counter supplements containing alpha-galactosidase, such as Beano, can help break down the oligosaccharides before they cause digestive issues.
Pressure Cook for Best Results: Using a pressure cooker is a highly efficient way to break down the complex sugars and antinutrients in beans, making them much more digestible.

Beans are a nutritional powerhouse, celebrated globally for their high protein, fiber, and mineral content. They are a cornerstone of many healthy diets, from Mediterranean to plant-based. However, the question of whether it is difficult to digest beans is common, and for many, the answer is a resounding yes. This is primarily due to specific complex sugars and other compounds that the human body finds challenging to break down, at least initially. Understanding the science behind this digestive difficulty and employing the right preparation techniques can help you reap the benefits of beans without the discomfort.

The Digestive Science Behind Beans

Why Beans Cause Gas and Bloating

Beans are notoriously known for their gas-producing effects, which are caused by indigestible complex carbohydrates called oligosaccharides. Humans lack the enzyme alpha-galactosidase, which is necessary to break down these sugars in the small intestine. As a result, the oligosaccharides travel to the large intestine where they are fermented by gut bacteria, producing gases such as methane, carbon dioxide, and hydrogen. This fermentation process is what leads to gas, bloating, and abdominal discomfort.

The Role of Phytic Acid and Lectins

Beyond oligosaccharides, beans contain other compounds known as "antinutrients" that can interfere with digestion and nutrient absorption. Phytic acid, for example, can bind to minerals like zinc, iron, and calcium, making them less available for your body to absorb. Lectins are another type of protein found in beans that can cause digestive issues, though proper cooking significantly reduces their levels. Raw or undercooked beans, especially kidney beans, contain high levels of lectins, which can cause severe digestive distress and should always be avoided.

Techniques to Make Beans Easier to Digest

Here are several proven methods to reduce the digestive difficulty of beans:

Soaking: This is one of the most effective strategies. Soaking dried beans overnight (or for at least 8-12 hours) in plenty of water helps to dissolve and remove a large portion of the oligosaccharides. Discarding this soaking water and rinsing the beans thoroughly before cooking is a crucial step to eliminate the gas-causing compounds. For even greater effect, some recommend changing the soaking water multiple times.
Pressure Cooking: Using an Instant Pot or other pressure cooker dramatically speeds up cooking time and is highly effective at breaking down the tough-to-digest compounds like lectins. The high heat and pressure make beans more digestible without requiring the extensive simmering time of traditional methods.
Adding Spices and Herbs: Incorporating certain spices and herbs while cooking can help. Cumin, ginger, fennel seeds, and asafoetida (hing) are traditionally used in many cuisines to aid in the digestion of beans. Adding a strip of kombu (seaweed) to the cooking pot also helps break down the oligosaccharides.
Introducing Gradually: If you are new to eating beans or haven't had them regularly, a sudden increase in fiber can overwhelm your digestive system. Start with small portions, such as a quarter cup, and gradually increase your intake over several weeks. Your gut microbiome will adapt, and you'll build up a tolerance to the fiber and other compounds.
Cooking Thoroughly: Always ensure beans are fully cooked until tender. Undercooked beans are harder to digest and can contain harmful lectins. Slow cooking over a long period can also help break down the fibers effectively.
Rinsing Canned Beans: While canned beans are already cooked, they are often packed in liquid containing some of the oligosaccharides. Rinsing canned beans thoroughly in a colander before use can help reduce these compounds and minimize bloating.

Comparison of Beans and Digestibility

Not all beans are created equal when it comes to digestibility. Here is a comparison of some common types:


Bean Type	General Digestibility	Why?
Lentils (Red & Yellow)	Easiest to Digest	Smaller size and lower oligosaccharide content. They also cook faster, which further helps.
Mung Beans	Very Easy to Digest	Low in oligosaccharides and prized in Ayurvedic medicine for being gentle on the stomach.
Black-Eyed Peas	Moderately Easy	Contain lower levels of indigestible fibers compared to larger, tougher beans.
Chickpeas (Garbanzo Beans)	Moderately Digestible	Generally well-tolerated when properly soaked and cooked. Soaking for up to 24 hours can help.
Pinto Beans	Variable	Can be harder to digest for some due to higher oligosaccharide content, though soaking helps.
Black Beans	Variable	Soaking and proper cooking are key to reducing the oligosaccharides found in black beans.
Kidney Beans	Most Difficult	High lectin content means they are particularly harsh if undercooked. Always soak and cook thoroughly.
Navy Beans	Most Difficult	Like kidney beans, they have a high oligosaccharide content, making them challenging for some.

The Role of Digestive Supplements

For those who continue to struggle even with proper preparation, over-the-counter supplements can provide additional support. Products like Beano contain the enzyme alpha-galactosidase, which helps break down the complex carbohydrates before they reach the colon. These supplements are taken with the first bite of a meal containing beans to be most effective. Other enzyme formulas, like BeanAssist, are also specifically designed for breaking down gas-inducing foods like beans and cruciferous vegetables.

Conclusion: Navigating Bean Digestion with Confidence

While the initial answer to the question "is it difficult to digest beans?" might be yes for many, this does not mean you have to give up on this incredibly healthy and affordable food. By understanding the underlying reasons for digestive discomfort—primarily the presence of oligosaccharides and other compounds—you can take proactive steps to mitigate these effects. Through simple yet effective methods like soaking, rinsing, and cooking thoroughly, you can make beans much more gut-friendly. Choosing easier-to-digest varieties like lentils and mung beans, introducing them slowly into your diet, and considering digestive enzyme supplements are all viable strategies. With a little patience and preparation, you can enjoy the substantial nutritional benefits of beans without the associated gas and bloating. A healthy, bean-filled diet is well within reach for everyone.

Explore more detailed information on making legumes more digestible from a trusted health source.

Frequently Asked Questions

Beans contain complex carbohydrates called oligosaccharides, which humans cannot fully digest due to the lack of the alpha-galactosidase enzyme. These sugars pass into the large intestine, where gut bacteria ferment them, producing gas and causing bloating.

Yes, soaking is one of the most effective methods. Soaking dried beans overnight in water and then discarding that water removes a significant portion of the gas-producing oligosaccharides. Rinsing thoroughly before cooking further aids this process.

Canned beans are pre-cooked and often contain fewer oligosaccharides than dried beans. For even better results, rinsing canned beans thoroughly before use can wash away some of the remaining gas-producing compounds in the canning liquid.

Smaller legumes like red and yellow lentils, mung beans, and black-eyed peas are generally considered the easiest to digest. They contain fewer oligosaccharides than larger beans.

Beano is a digestive enzyme supplement that contains alpha-galactosidase. By taking it with your first bite of beans, you are providing your body with the necessary enzyme to break down the complex oligosaccharides before they cause gas.

Yes, some spices like bay leaves, cumin, fennel, and ginger have traditional and proven properties that help in breaking down digestive inhibitors and soothing the digestive tract when cooked with beans.

Pressure cooking beans is a highly effective way to increase their digestibility. The high heat and pressure break down the lectins and complex sugars much more efficiently than standard stovetop simmering.