DEAR DR. BLONZ: One of my New Year's resolutions -- a work still in progress -- is to reduce the amount of gas my stomach produces. I was hoping you might help with some advice. -- B.F., Chicago
DEAR B.F.: While there may be likely "suspects," foods can affect people differently. Any of a wide variety of foods can appear on a particular person's "gas" list.
The common culprits, which you are likely already aware of, include dairy products, beans (and other legumes), certain grains, vegetables, nuts and seeds. Legumes have a notorious reputation for gas because they contain carbohydrates known as oligosaccharides, which the body lacks the enzymes to disassemble efficiently (an essential step before absorption). They pass into the large intestine, where they serve as fuel for the bacterial flora living there; gas is produced as a metabolic byproduct.
While it all seems straightforward, the gassy nature of the same food can vary from meal to meal. For example, a glass of skim milk or a bowl of beans on an empty stomach would be expected to produce more noticeable gas than the same serving eaten with a large, mixed meal. This is explained by the slower rate at which the meal's combination of protein, fat and carbohydrates travels through the digestive system. When it finally arrives at the large intestine, there's a mixture of materials to occupy the attention of the flora. If a single gassy food is eaten, the flora gets to focus on that problem-causing material -- with predictable effects. (Our dietary habits help determine the nature of the flora population that thrives.)
It's also known that some people can tolerate large servings of foods that cause excessive gas in others. It's unclear how much of this is due to differences in digestive ability, how often we eat a particular food, or even such factors as whether we're relaxed or anxious, the speed at which we eat or how completely we chew.
While food tends to be the primary suspect, minor digestive upsets can also be a reaction to supplements and medications. Another question to consider: Was there an event or some recent travel after which things seem to have gotten worse? Anything that persists should be investigated more thoroughly with your health professional.
If you are constantly bothered by gas, consider keeping a food diary as part of your effort. On the days your problem is most bothersome, note the foods you have eaten in the previous few days, along with the meal conditions and even your state of mind. Often a pattern emerges that can give you hints about ways to eat, methods of preparation, or more tolerable serving sizes. Over-the-counter products can help with the more troublesome carbohydrates. If milk is the issue, there are pills and drops that can supply the enzyme (lactase) that digests the gas-causing lactose. Or you can drink lactose-reduced milk.
Again, as with any physical complaint -- especially those involving digestive problems -- be sure to discuss the situation with your health professional.
Send questions to: "On Nutrition," Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.