Beans and Digestive Problems

Beans are nutritious, providing essential nutrients like protein, vitamins, and minerals.

However, many people avoid beans due to their digestive side effects. Properly cooking beans and adding them to your diet slowly can help reduce symptoms like gas and bloating.

Why Beans Cause Gas and Bloating

Beans are part of the legume family, which includes chickpeas, lentils, soybeans, and peas. They are high in oligosaccharides, a type of indigestible fiber.

Because the body can’t digest the oligosaccharides in beans and other legumes, they end up in your large intestine, where beneficial bacteria ferment them. This process releases gases, which can cause digestive issues like bloating or cramps.

Some Beans May Cause Less Gas Than Others

While all legumes are considered high in fermentable fiber, some contain more than others. Choosing those lower in oligosaccharides may help reduce intestinal discomfort.

According to a review of the fiber content of legumes, those higher in oligosaccharides include:

• Green peas
• Lentils
• Soybeans

Legumes lower in oligosaccharides include:

• Fava beans
• Green beans
• Kidney beans

How to Prevent Gas From Beans

Aside from choosing beans that are lower in fermentable fiber, there are some other things you can do to make them easier to digest.

Soak Beans Before Cooking Them

When cooking dried beans, soaking them before boiling makes them easier to cook. It can also reduce the amount of oligosaccharides that cause gas and bloating.

A study published in Food Research International analyzed the oligosaccharide content of a variety of legumes after soaking them at different temperatures.

Researchers found that soaking beans for one to three hours in water at 45 degrees C (113 degrees F) reduced alpha-galactosidase, a type of oligosaccharide, by 50 percent. Using water that is slightly acidic seems to contribute to this process.

Change Out the Cooking Water

Once you’re done soaking, pour out the soaking water and replace it with fresh water to cook.

Once the cooking process is complete, pour out that water and replace with new water, if desired.

According to a study published in the Journal of Nutritional Science and Vitaminology, this can reduce the oligosaccharide content by 25 to 85 percent, depending on what type of bean or lentil you might be cooking.

Introduce Beans Slowly

Increasing your fiber intake too quickly can make digestive problems worse. Slowly introducing beans to your diet gives your body time to adjust to the added fiber.

A study published in Nutrients looked at the effects of added dietary fiber on gastrointestinal comfort in 38 participants. In the first week, participants frequently reported experiencing gas and bloating. By the second week, participants reported no adverse digestive symptoms.

A Note About Toxins

Raw or undercooked beans contain the protein lectin. In high amounts, lectin can cause nausea, vomiting, and diarrhea. While canned beans shouldn't pose a risk, soaking and boiling dried beans until they are fully cooked removes lectin, making them safe to eat.

Should You Still Eat Beans?

Beans are high in protein compared with other plant foods. They are an excellent source of fiber, antioxidants, and phytonutrients (compounds thought to be protective to cells).

Beans are also a good source of vitamins and minerals like folate, iron, and magnesium. Despite the discomfort they can cause, the oligosaccharides in beans also act as a prebiotic.

Prebiotics are foods that support the growth of beneficial bacteria in your gut. Research suggests these bacteria provide a range of health benefits, including reducing inflammation, improving immune function, and increasing calcium absorption.

According to a large women’s health study involving over 64,000 women, higher intakes of total legumes were associated with a 38 percent lower risk of type 2 diabetes. Researchers also found that higher intake of soybeans was associated with a 47 percent lower risk of type 2 diabetes.

Multiple systematic reviews and meta-analyses have found that higher legume consumption is associated with a 6 to 14 percent reduction in incident heart disease risk. The highest benefits are associated with consuming around 400 grams (about 3 cups) of legumes per week.

Other benefits include lower total and LDL (“bad”) cholesterol, reduced blood pressure, and improved cardiometabolic risk factors.

When properly cooked and added slowly, even just a tablespoon a day to start, beans can be an important part of your diet without having to worry about gas.