Posted on: Saturday, October 11, 2003

PRESCRIPTIONS
Lactose intolerance may be cause of gassiness

By Landis Lum

Q. I get gassy with certain yogurts but not others. Does this mean that the former have more live and active cultures?

A. It is likely that your gassiness is caused by lactose intolerance, which is an inability to completely digest the milk sugar lactose because your small intestine no longer produces as much of the lactase enzyme it used to when you were younger. Lactase breaks down lactose. Without lactase, undigested lactose enters the large intestine, where fermentation by bacteria leads to gas production, bloating, cramping and often diarrhea. Asians are particularly vulnerable to this problem. Lactose intolerance affects about 10 percent of Caucasians but afflicts 90 percent of Asians and Native Americans.

Yogurts with active cultures actually lead to less or even no gas, because the bacteria produce natural lactase enzymes that help break down lactose. People with lactose intolerance should try eating yogurts with active cultures (read the label), because dairy products are an important source of calcium, and slender Asian and Caucasian females are especially prone to osteoporosis. However, just because the yogurt has an active culture doesn't necessarily mean it's more beneficial.

Different yogurts have different amounts of bacteria-derived lactase enzymes. And when I visited my favorite lunch place — Down To Earth in Kailua — and scouted out their yogurts, I noticed that some Alta Dena products had lactase enzyme while others didn't; the ones with added lactase might cause less gas.

Many people think they are lactose intolerant but really aren't. Try stopping all dairy products for two weeks, including milk, cheese, yogurt, ice cream, breads and certain candies, cold cuts, dessert mixes and cream soups to see if symptoms improve then worsen after resuming dairy products. When bacteria ferment lactose in your large intestine, hydrogen is produced, enters the blood stream, and goes to your lungs. Therefore, ingesting dairy products will increase the hydrogen content of your breath. If necessary, we can do a breath hydrogen test to confirm the diagnosis. If you do have lactose intolerance, you can continue to eat dairy products if you chew lactase enzyme pills such as Dairy Ease or Lactaid whenever you eat dairy products. Or you can buy lactose-reduced milk. Besides building strong bones, dairy products also help prevent high blood pressure.

Even without lactase enzyme tablets, you can usually drink an eight-ounce glass of milk twice a day if taken with your breakfast and dinner meals and not get symptoms.

If you don't eat much dairy, then eat foods high in calcium, such as leafy greens (including collard, kale and mustard greens), canned salmon (if you eat the salmon bones), shrimp, broccoli, orange juice with added calcium and Brussels sprouts. But you may need to take calcium supplements — most women do not get enough calcium in their diet, and develop a hunched back or hip fractures in later life.

Dr. Landis Lum is a family-practice physician for Kaiser Permanente and an associate clinical professor at the University of Hawai'i's John A. Burns School of Medicine. Send questions to Prescriptions, Island Life, The Advertiser, P.O. Box 3110, Honolulu, HI 96802; fax 535-8170; or write islandlife@honoluluadvertiser.com.