Are You Lactose Intolerant?

By Jane Farrell

If you find yourself suddenly having unpleasant digestive effects from dairy products, the culprit might be lactose intolerance. Even if you’ve never suffered from it, lactose intolerance can manifest itself in adulthood. Here, from the National Digestive Diseases Information Clearing House (NDDIC), part of the National Institutes of Health (NIH), is some information on what it is, why you might have it and how you can manage it:

According to the NDDIC, lactose intolerance means that you have an inability or insufficient ability to digest the sugar lactose, which is found in milk and milk products. That lactose intolerance is caused by a deficiency of the enzyme lactase, which normally breaks down lactose into two forms of sugar that are absorbed in the bloodstream.

It can be an elusive condition: not all people with lactase deficiency have symptoms, but those who do probably have lactose intolerance, according to the NDDIC. Additionally, lactose intolerance is sometimes confused with allergy to cow’s milk. But milk allergy is an immune-system reaction to one or more milk proteins and can be life threatening when just a small amount of milk or milk product is consumed. It usually appears in the first year of life, while lactose intolerance occurs more often in adulthood.

Primary lactase deficiency develops over time and begins about age 2 when the body begins to produce less lactase, the NDDIC says, although many people don’t show symptoms until late adolescence of adulthood. Secondary lactase deficiency occurs with digestive illnesses like severe diarrheal disease, Crohn’s or celiac disease, or because of chemotherapy.

It can be hard for a physician to diagnose lactose intolerance based on symptoms alone, according to the NDDIC. You may think you have lactose intolerance because you have digestive symptoms. However, that could be due to irritable bowel syndrome and similar conditions. A physician will likely recommend eliminating all milk and milk products to see if that makes a difference.

Beyond that, there are two commonly used tests to measure lactose digestion.

Hydrogen Breath Test. The person drinks a lactose-loaded beverage and then the breath is analyzed at regular intervals to measure the amount of hydrogen. Undigested lactose produces high levels of hydrogen. Before taking the test, patients should ask their doctors about foods and medicines that could interfere with the test results.

Stool Acidity Test. The stool acidity test is used for infants and young children to measure the amount of acid in the stool. Undigested lactose creates lactic acid and other fatty acids that can be detected. How is lactose intolerance managed?

Your body’s ability to produce lactase can’t be change. But, the NDDIC emphasizes, the symptoms of lactose intolerance can be controlled. Even if you have lactose intolerance, you can probably tolerate a small amount of lactose.  Sometimes a patient’s tolerance of lactose might depend on the size of the portion or whether the food was taken with a meal.

According to the NDDIC, the Dietary Guidelines for Americans recommend that people with lactose intolerance choose milk products with lower levels of lactose than regular milk, such as yogurt and hard cheese.  Other good choices include lactose-free and lactose-reduced milk and milk products, which are identical to regular milk except that the lactase enzyme has been added.

The NDDIC also says that people who still experience symptoms after dietary changes can take over-the-counter lactase enzyme drops or tablets. The medicine can be taken when eating milk or milk products.

If you’d rather avoid milk products altogether, you can get calcium from other sources, the NDDIC says, including broccoli, spinach, salmon, soy milk, lettuce and tuna.

For more information about digestive illnesses, click here to visit the NCCID’s website.