Please note: This information was current at the time of publication but now may be out of date. This handout provides a general overview and may not apply to everyone. For regularly updated information on a variety of health topics, please visit, the AAFP patient education website.

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Am Fam Physician. 2006;74(11):1927-1928

What is lactose intolerance?

If you have lactose intolerance, you have trouble digesting milk, cheese, and other dairy products. This condition is most common in people of Asian, American Indian, Hispanic, South American, or black heritage.

What causes lactose intolerance?

If you have lactose intolerance, you have trouble digesting milk because your body does not make enough lactase. Lactase is an enzyme that breaks down the natural sugar in milk. This sugar is called lactose.

What problems does lactose intolerance cause?

The main problems caused by lactose intolerance in adults are:

  • Rumbling tummy sounds

  • Gas

  • Stomach cramps

  • Stomach bloating

  • Diarrhea

The condition is different in each person. Some people with this problem can safely drink small amounts of milk, especially if they eat food with it. Other people can’t drink any milk at all without having problems. The problems often start around two years of age, when the body naturally starts making less lactase.

How is lactose intolerance treated?

You can make changes in your diet that will help you digest milk, or you can get your calcium from other foods.

Milk and milk products are an important source of calcium. Your goal should be to get 1,200 to 1,500 mg of calcium each day. Children, teenagers, women who are pregnant or breastfeeding, and women who have gone through menopause should take calcium supplements if they can’t drink enough milk or eat enough dairy products to get this much calcium.

Ask your doctor if you should take calcium supplements. There are many kinds. The supplements with an oyster shell base are absorbed best. Check the amount of calcium on the product label. Some antacids have a lot of calcium in them. They make a good calcium supplement if you have to take antacids anyway.

If you can, eat and drink smaller servings of dairy products, but have them more often. The smaller the serving, the less likely it is that you’ll have problems.

Eat food when you drink milk. This slows the digestive process, and you have less chance of having problems.

You may not have any trouble eating yogurt if it includes an active culture. Check the label to see if active culture is included.

Ice cream, milk shakes, and aged (hard) cheeses are easier to digest than milk for most people with lactose intolerance, but these foods are high in fat. If your weight and cholesterol and triglyceride levels are normal, you can try them.

Look for lactose-reduced milk in your grocery store. It has about 70 percent less lactose than regular milk, but it costs a little more.

Try adding lactase to regular milk. You can buy lactase at drug stores. Some people like the flavor of milk with added lactase because it tastes sweet.

Instead of drinking milk, eat foods that are high in calcium, like leafy greens (such as collards, kale, and mustard greens), oysters, sardines, canned salmon (if you eat the salmon bones), shrimp, broccoli, and brussels sprouts. You can buy orange juice with added calcium.

Where can I get more information?

Your doctor

National Digestive Diseases Information Clearinghouse

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Copyright © 2006 by the American Academy of Family Physicians.

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