Research Stories

by Melissa Crytzer Fry

"Beans, beans, the musical fruit
The more you eat, the more you toot!"

Everyone remembers the childhood rhyme. But is it true? Do beans really cause flatulence? ASU nutritionist Donna Winham wanted to test the theory.

Participants in both of Winham's bean studies were asked to eat pinto beans, black-eyed peas, and vegetarian baked beans. They also completed questionnaires related to digestive comfort and flatulence as part of those studies.

"We asked study participants if they experienced increases in flatulence, stool frequency, or bloating," Winham says. "They also had to rank any problems on a scale of 1 to 5. Very few people actually had continual problems."

Winham says that during the first two weeks of the study about half of the participants reported issues with increased flatulence. By the third and fourth weeks, those issues had completely dissipated for most.

The verdict: beans may not be as musical as suggested.

Winham thinks that flatulence issues are more likely related to the quantity of beans consumed by a person in a single meal.

"Lots of people will eat the entire can of beans. That is equivalent to three and a half servings. And then they wonder why they have gas," she says.

Winham says that the increased amount of fiber can upset the stomach of an individual who doesn't generally consume as much fiber. Her advice? Begin by eating a quarter-cup of beans each day. Then gradually increase the amount to a half-cup.

Read about the nutritional benefits of beans in "Full of beans."