Do you get bloated, have cramps or diarrhea from drinking a glass of milk or eating a piece of cheese?

If you do, then you are one of an estimated 35 million American adults who are lactose intolerant, or unable to easily digest a major component in milk and some other dairy foods.By following a few simple eating tips or using an enzyme supplement, most people with lactose intolerance can consume dairy foods without unpleasant side effects.

Being able to eat dairy foods makes for a more varied diet and makes it easier to get the calcium the body needs, said Una Finn, a registered dietitian at New York University Medical Center.

Dairy products provide about 70 percent of the calcium in the typical American diet. Insufficient calcium intake has been linked to osteoporosis, a condition that affects millions of older adults, making their bones porous.

The largest single nutrient in milk is a complex sugar called lactose. The body produces an enzyme called lactase which breaks lactose down into simple sugars which are easily absorbed.

The eating of dairy products often brings on symptoms of lactose intolerance such as gas, cramps, bloating or diarrhea.

"The severity of symptoms is directly related to the level of lactase deficiency and the amount of lactose consumed," Finn said.

Not all dairy products have the same amount of lactose. Hard cheeses, for example, an excellent source of calcium, have very little lactose, and so are well tolerated by most people. Cottage cheese has only a third as much lactose as milk.

Symptoms of lactose intolerance can be eliminated or reduced in most people by consuming only a small quantity of milk or dairy foods at any one sitting.

People whose symptoms cannot be controlled by any of the above measures, but who still want to consume dairy products, can use a lactase enzyme supplement, Finn suggested.

The enzyme supplements are readily available without prescription at most drugstores. Many grocery stores sell milk and some cheeses that have lactase enzyme already added to them.

"Dairy products treated with lactase enzyme are essentially the same as their regular counterparts in nutritional value and flavor," Finn noted.

The amount of enzyme used can be adjusted to break down some or virtually all of the lactose, depending on the individual's needs.

A few drops of liquid lactase enzyme can be added to milk 24 hours ahead of time. A larger dose of lactase, in powder or pill form, often works just as well if added to dairy foods or swallowed just before eating.

People who suspect they are lactose intolerant should see a doctor to rule out other more serious digestive problems and to get advice on other possible ways to increase their tolerance.

"And be aware that many liquid diets, medications and `non-dairy' products contain lactose," Finn added. "So check ingredient labels for lactose, milk solids or whey."