Doctor's Diagnosis: Lactose intolerance

Virtually everyone either is directly affected by lactose intolerance or knows someone who is. This is because the majority of adults have some degree of lactose intolerance.

Despite this being so common, most patients have little understanding of what their problem actually is. For example, I’ve heard many people say they are “allergic” to lactose, but lactose intolerance is not an allergy.

Lactose is a type of sugar. More precisely it is two different sugars bound together. The body cannot directly absorb lactose; it must first split the lactose into its two parts. This is done by an enzyme called lactase, which is produced by the lining of the small intestine.

As children, we all make lactase, which is very important because lactose is the main sugar found in milk. The problem is that when we become adults, many of us stop making sufficient amounts of lactase. Without it, we can no longer absorb the lactose. Since we don’t absorb it, the bacteria in our intestines use it as an energy source, in the process releasing undesirable products.

The results can be explosive. Within 30 minutes to two hours of consuming lactose, patients complain of bloating, abdominal pain, diarrhea and passing gas. The problem is usually diagnosed by the history alone or by having patients experiment with a lactose-free diet. If needed, there are tests available to confirm the diagnosis.

There is no way to make the body produce more lactase. Most often, patients simply learn to avoid lactose-containing foods such as milk, ice cream, yogurt or cheese, especially soft ones such as cottage cheese.

Typically patients can tolerate small quantities of these products, but the amount varies from person to person, and trial and error is needed to determine individual limits. Especially sensitive patients must use extra caution because small amounts of lactose can also be present in unexpected products such as cereals, salad dressings or even certain medications.

All is not lost if you are one of the millions of people suffering from this problem. Products are available such as “lactose-free” or “lactose-reduced” milk, which is milk that has lactase added to it.

Lactase itself is available in pill or liquid form and can be taken immediately before consuming lactose containing foods or added to cartons of milk.

Dr. Stephen Picca of Massapequa is Board Certified in both Internal Medicine and Anesthesiology. He is retired from practice. Questions and comments can be sent to Dr. Picca at health@newsday.com.