What You Should Know About Beans and the (Embarrassing) Gas They Cause

Over time, flatulence should fade
The Musical Fruit: What You Should Know About Beans (and Gas)

Black beans. Lentils. Garbanzos. Kidney beans. Pintos.

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Beans and legumes are a vital part of the Mediterranean diet, which protects against heart disease, dementia, cancer and other chronic illnesses.

The problem with beans is that digesting their sugars often creates a fragrant, musical byproduct: gas, or flatulence.

Is there any way to avoid the tooting horns … and unpleasant odor?

“No studies have yet shown that a particular method of soaking or cooking beans prevents flatulence,” says integrative medicine physician Irina Todorov, MD.

“But that doesn’t mean you can’t experiment with different methods — or different legumes.”

More legumes, more fiber

When your doctor tells you to eat more beans, says Dr. Todorov, the extra fiber you’re getting creates gas.

“Beans, legumes and soy each have 6 to 8 grams of fiber per half-cup,” she says. If you suddenly start eating 1 cup of beans per day, that’s a big increase.

Typically, gas levels will return to normal once you’re eating legumes regularly.

Does the type of bean matter?

A review of three studies found that different legumes cause different amounts of gas.

Researchers compared the flatulence people reported after eight weeks of eating one-half cup of these foods in various combinations:

  • Pinto beans.
  • Black-eyed peas.
  • Vegetarian baked beans.
  • Canned carrots.

In the first week, black-eyed peas caused less flatulence than either the pinto beans or baked beans.

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But after three to four weeks, flatulence levels for all the beans returned to normal as people adjusted to the increased fiber.

Dr. Todorov points out, however, that 6 to 12 percent of the people saw no decrease in gas with any bean.

“People vary in their response to different legumes,” she says. “So if one type of bean gives you problems, switch to another type to see if it gives you less gas.”

The control group, who ate only baked carrots, also reported flatulence — probably because carrots contain fiber, too, she says. But gas levels eventually returned to normal for them, too.

Soaking: Does it help?

“I always soak my beans overnight, throw out the leftover unabsorbed water, then fill the pot with fresh water and start the cooking process,” says Dr. Todorov.

“Why? Because my mother and grandmother told me to!”

Is there any research to support this? Researchers in India looked at five different types of beans, soaked in:

  • Plain water for six hours.
  • Plain water for 12 hours.
  • Water with baking soda (1/16 teaspoon per quart) for six hours.
  • Water with baking soda for 12 hours.

Afterward, they measured the levels of gas-producing substances left in the beans.

They found the fewest in beans soaked for 12 hours. Whether they were soaked in plain water or water with baking soda didn’t matter.

“But remember not to cook the beans in the baking soda water,” notes Dr. Todorov. “That may cause the beans to lose some of their vitamins.”

What about adding herbs?

Perhaps your family has passed on a special method of cooking beans from one generation to the next.

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For instance, you may have been taught to add one of these herbs to boiling beans to make them more digestible:

  • Peppermint.
  • Ginger.
  • Fennel.
  • Cumin seeds.
  • Garlic.
  • Onion.

While not backed by science, “There is no harm in trying any of these methods,” says Dr. Todorov.

“The herbs are part of the Mediterranean diet, and will add great taste to your dish. And some of them are used to help digestion.”

Finally, it’s common in some Asian cultures to add a dried piece of kombu seaweed to beans as they boil to make them more digestible. You remove the kombu once the beans are done.

“Kombu seaweed can be found in most Asian food and health food stores,” she says.

Why you shouldn’t give up on beans

Don’t let flatulence keep you from enjoying beans in the soups, stews, chili and many other dishes popular around the world.

You don’t want the occasional “trumpet solo” to keep you from enjoying their serious health benefits.

“In one seven-year study, legume consumption was the most important predictor of survival in people aged 70 and older,” says Dr. Todorov.

You may find some beans easier to digest than others. And once these “musical fruits” become part of your diet, you shouldn’t have to worry about gas.

“Find out which beans suit you best, and keep eating them,” she advises.

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