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Star Bulletin Alan Titchenal & Joannie Dobbs Health Options
Alan Titchenal
 & Joannie Dobbs
                   Monday, October 11, 2004


High-carb food can be a gas to eat at times

Despite the low carb-craze, it is clear that many high-carbohydrate foods promote good health. Fruits, vegetables, beans and grains are all associated with a decreased risk of multiple chronic diseases.

Still, people come up with many excuses for not eating more of these health-promoting foods. Excuses range from taste to cost. One of the most common, yet least-mentioned, excuses is increased flatulence -- the polite word for intestinal gas. Along with the challenge of politely releasing these gasses, people also complain of abdominal bloating and discomfort.

Question: What foods cause flatulence?

Answer: This varies from person to person, but common offenders are legumes (beans, peas, lentils, etc.), vegetables, fruits, whole grains and some nuts and seeds.

Q: Why these foods?

A: They contain forms of carbohydrate that can't be digested or absorbed in the upper part of the intestine. Beans are famous for this because they contain some oddball sugars called raffinose and stacchyose, neither of which can be digested because of a lack of the enzymes required for digestion.

These sugars pass into the lower intestine, where a thriving population of bacteria can do what we can't. They digest these sugars for their own energy needs -- but the byproduct of that process is gas.

Some forms of dietary fiber also can be partially used by bacteria, with the same gassy result.

So, when we pass along excessive amounts of sugars or fibers to the lower intestine, you could say that the bacteria have a party and "get gassed." The result for us is flatulence.

Q: What causes the feeling of bloating?

A: This is related to a temporary expansion of the contents of the lower intestine (or colon), due to gas or fluid accumulation. The average person produces between a half a quart to a quart of gas each day. Yes, scientists have actually measured this! The abdomen can become distended when more gas is produced. Also, the fibers in foods and fiber supplements hold onto water and temporarily increase intestinal fill until things move along.

Q: Why do some foods affect one person and not another?

A: The ecological balance of bacterial species in the lower intestine vary by individual. That balance also may change over time when the composition of the diet changes, and especially after a person takes antibiotics.

Q: What can help to reduce the gas production?

A: Three key things to consider:

» Drink plenty of water to keep fiber moving at an appropriate speed through the intestines.

» After taking antibiotics, gradually increase your diet of the offending foods to allow the bacterial balance in your intestines to adjust and normalize.

» Try a product called Beano. It contains an enzyme that can partially digest some of the offending sugars and fibers and reduce the supply of goodies for the bacteria waiting in the lower intestine.

Alan Titchenal, Ph.D., C.N.S. and Joannie Dobbs, Ph.D., C.N.S.
are nutritionists in the Department of Human Nutrition, Food and Animal Sciences,
College of Tropical Agriculture and Human Resources, UH-Manoa.
Dr. Dobbs also works with the University Health Service

© 2004 Honolulu Star-Bulletin --

Human Nutrition, Food & Animal Sciences · University of Hawai`i at Mānoa
1955 East-West Road · Honolulu, HI 96822
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