People with lactose intolerance do not have enough of the digestive enzyme lactase, which breaks down lactose. Lactose is the sugar in milk. It is found in dairy products and foods containing milk ingredients. People with lactose intolerance may experience discomfort or abnormal stools after eating foods containing lactose.
The small intestine makes the enzyme lactase. When it does make enough of the enzyme, the body cannot break down lactose, the sugar found in milk, and therefore has trouble digesting milk or milk products. Most babies' bodies make the enzyme, making it possible to digest milk, including breast milk. Once milk intake slows down, the body may stop making lactase in some children. Some people may not experience a problem until early adulthood and others will never experience lactose intolerance.
Approximately 30 million American adults have some amount of lactose intolerance. The condition is more common among Asian, African, African-American, Native American and Mediterranean populations than it is among northern and western European populations. People with celiac disease or gastroenteritis may also lack lactase. Temporary lactase deficiency may occur after a viral or bacterial infection that injures the cells lining the intestine.
People with lactose intolerance will experience symptoms approximately 30 minutes to 2 hours after eating or drinking foods containing lactose. Symptoms may include:
- Abdominal Pain or Cramping
- Diarrhea or Loose Stools
Exams and Tests
If your child's pediatric GI specialist suspects lactose intolerance, he or she may recommend a lactose tolerance test.
The hydrogen breath test measures the amount of hydrogen in a person's breath. Your child will be asked to breathe into a balloon-type container to get a baseline reading. Next your child will be asked to drink a flavored liquid that contains lactose. Breath samples will be collected at set time periods to test if the hydrogen level changes. If your child's body has trouble breaking down lactose, the hydrogen level in their breath will increase. Your child should not eat eight hours before the test.
Lactose intolerance may also be diagnosed by taking a biopsy of the small intestine during endoscopy.
The best way to treat the symptoms of lactose intolerance is to avoid milk-based products. People differ in the amount of lactose they can eat without having symptoms. Small amounts of milk and milk products (less than 1/2 cup) eaten with other foods at meals and snacks may be tolerated. Yogurt (with live cultures) or cheese may also be tolerated. There are lactose-free milks, such as Lactaid© or Dairy Ease©, which can be substituted for regular milk. There is also an enzyme replacement pill (Lactaid© or Dairy Ease©) that can be taken when lactose-containing foods are eaten.
Foods containing lactose
- Cream Cheese
- Ice Cream
- Acidophilus Milk
- Cottage Cheese
- Ice Milk
- Sour Cream
Ingredients on labels that indicate lactose is present
- Milk, milk solids
- Milk by-products
- Malted Milk
- Skim or non-fat dry milk powder
Foods that may have hidden lactose
- Baked goods: bread, cookies, cakes, pancakes, waffles
- Cream Soups
- Sauces and gravies
- Instant Potatoes
- Hot dogs, bologna, cold cuts, other lunch meats
- Salad Dressing
- Beverage or chocolate drink mixes
- Processed breakfast cereals
Some individuals need to avoid all lactose-containing foods. All food labels must be checked carefully to make sure they do not contain milk or lactose. If milk and milk products are not used, sufficient calcium intake from other foods or supplements needs to be provided to your child. A dietician can help you determine the best diet for your child.
Points to Remember
- Lactose intolerance is a condition in which the body cannot break down lactose, a sugar found in milk.
- Lactose intolerance is caused by a deficiency of the enzyme lactase.
- The condition can appear during early childhood all the way to early adulthood.
- The best way to treat lactose intolerance is to avoid foods containing lactose. Lactose-free milk and enzyme replacement pills are available.
For More Information
American Gastroenterological Association - gastro.org/wmspage.cfm?parm1=854
International Foundation for Functional Gastrointestinal Disorders - aboutkidsgi.org/site/about-gi-health-in-kids/other/lactose
National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health - digestive.niddk.nih.gov/ddiseases/pubs/lactoseintolerance/