Lactose Intolerance Unsettles Millions of Us

Lactose intolerance, the inability to comfortably digest milk, affects a huge number of people: between 30 and 50 million Americans have the disorder.

The symptoms of lactose intolerance can be quite uncomfortable, including abdominal pain, cramping, gas, and diarrhea "But the good news is that it is not life-threatening, that it is very common - you have company with this condition - and that it is easily treatable," says Jasmohan Bajaj, MBBS, MD, Assistant Professor of Medicine at the Medical College of Wisconsin. Dr. Bajaj practices at the Froedtert & The Medical College of Wisconsin Gastroenterology and Hepatology Clinic.

Lactose intolerance is caused by a shortage of the enzyme lactase, which breaks down the sugar in milk into simpler sugars that are easier to digest. When the body can't digest milk, the unpleasant symptoms are triggered. "Lactase is one of the most precarious enzymes and can be neutralized by many conditions," causing lactose intolerance, notes Dr. Bajaj. "Lactase happens to be an enzyme that can be easily knocked out."

However, stresses Dr. Bajaj, treatment is usually relatively simple once the problem is diagnosed. "A lot of people seek medical treatment because they are not sure what it is that's bothering them," he explains.

Prevalence
For reasons still uncertain, lactose intolerance is concentrated among African Americans (an estimated 80% have it), American Indians (80% to 100%) and Asian Americans (90% to 100%). The condition is rarely found among people with Northern European backgrounds. While theories about these ethnic differences abound, a conclusive explanation is still lacking, says Dr. Bajaj.

Although many lactose intolerance cases are due to the genetic predisposition that comes with ethnic background, other cases result from digestive diseases that interfere with the body's ability to produce the lactase needed for proper digestion of milk. These include celiac disease and inflammatory bowel diseases such as Crohn's disease.

People sometimes confuse lactose intolerance with cow's milk intolerance because the symptoms are often the same. However, lactose intolerance and cow's milk intolerance are not related. Lactose intolerance is a problem caused by the digestive system, while cow's milk intolerance is an allergic reaction triggered by the immune system.

Lactose intolerance is clearly distinct from an allergy to milk. The milk allergy shows up early in children and produces itching, hives, nausea, and stomach pain. The only treatment for this rare condition is complete avoidance of milk and milk products, Dr. Bajaj states.

In contrast, the treatment of lactose intolerance is much easier. Once the problem is diagnosed, a fairly simple change in dietary habits will make a big difference in the patient's life.

Testing
In most cases, the tests for lactose intolerance are straightforward and easy. One is a breath test that analyzes the level of hydrogen in patients' breath after they have consumed a lactose-laden beverage. A high level of hydrogen in the breath indicates that the body is not properly digesting lactose.

The second major test involves carefully following a specific lactose-free diet outlined by your health care provider. "You follow the diet rigorously, and then we see if the symptoms improve. If they do, then that means you are likely to be lactose intolerant," says Dr. Bajaj

Self-Care
Dr. Bajaj notes that people who experience the discomfort of lactose intolerance can take steps to assess their condition and possibly reduce their symptoms:

• Evaluate your body's responses when you consume milk and milk products (like ice cream and cheese), which vary substantially from person to person with the condition. "You may want to avoid it, or at least know your comfort zone - how much you can comfortably consume," Dr. Bajaj says.
• Look for the enzyme lactase, which is available over-the-counter in both tablet and liquid forms. "You should take some with your first bite of dairy food," Dr. Bajaj advises.
• Choose substitutes for conventional milk - like soy milk and lactose-reduced milk- that are now widely available. "Almost all grocery stores are well-equipped with alternatives to milk and milk products," Dr. Bajaj notes.
• Check food labels for milk byproducts, including curds, whey, and non-fat dry milk powder. People with a very low tolerance for lactose might experience problems with foods containing small amounts of lactose, such as breads, margarine, lunch meats, salad dressings, snacks, and mixes for cookies, pancakes, and biscuits.
• If you are skipping or going light on milk products, work out a diet that provides nutrients like calcium that you are missing. Alternative sources of calcium include fish like salmon and sardines and dark green vegetables such as broccoli. Surprisingly, yogurt is another good source of calcium for the lactose-intolerant, despite the relatively high lactose content. Yogurt contains bacterial cultures that aid in the production of the lactase enzyme needed in digestion.
• You might need vitamin supplements to get enough calcium and Vitamin D. Vitamin D, supplied by sunlight and foods such as liver and eggs, is vital to the absorption of calcium. Confer closely with your doctor or dietician before rushing out to buy vitamins or dietary supplements - the wrong vitamins or minerals might actually prove harmful.

While lactose intolerance can cause discomfort and inconvenience, Dr. Bajaj reminds patients that the condition poses no threat to their health and, with a bit of planning, can usually be treated fairly simply.

This article includes information from the National Institute of Diabetes & Digestive & Kidney Diseases.

MCW Health News presents up-to-date information on patient care and medical research by the physicians of the Medical College of Wisconsin.