Lactose Intolerance (cont.)
Bhupinder Anand, MD
In this Article
How are lactase deficiency and lactose intolerance diagnosed?
Although there are several good ways to diagnose lactose intolerance, most people who consider themselves lactose intolerant have never been formally tested for intolerance. This is unfortunate because at least 20% of people who think they are lactose intolerant are not, and 20% of people who think they are not intolerant, in fact, are intolerant.
Why should so many people believe that they are lactose intolerant when they are not? This erroneous belief may be common for several reasons. People with unexplained (undiagnosed) gastrointestinal symptoms are looking for an explanation for their symptoms. Since lactose intolerance is a well-known condition, it provides these people with a ready (and welcome) explanation for their symptoms. Confirmation that lactose intolerance is present often is made subjectively and without careful correlation between ingestion of milk or milk products and symptoms. Extrapolating from data on the effect of placebo, it can be hypothesized that between 20 and 40 percent of people who think they feel better on stopping milk, in fact, are no better. Feeling better for them is analogous to a beneficial (positive) response to placebo.
Formal testing for lactose intolerance is valuable. Not only can testing confirm lactose intolerance and prompt the institution of a reduced or lactose-free diet, but it also can exclude lactose intolerance and direct attention to diagnosing other conditions and diseases that are responsible for the symptoms.
Comment on this
Probably the most common way that people self-diagnose lactose intolerance is by an elimination diet, a diet that eliminates milk and milk products. There are several problems with this type of "testing."
If an elimination diet is to be used for diagnosing lactose intolerance, it should be a rigorous diet. A rigorous diet requires counseling by a dietician or reading a guide to a lactose-elimination diet. The diet also needs to be continued long enough to clearly evaluate whether or not symptoms are better. If there is doubt about improvement on the diet, particularly if symptoms normally fluctuate in intensity over weeks or months, repeated periods of lactose elimination should be tried until a firm conclusion can be drawn. Elimination of all milk products should eliminate symptoms completely if lactose intolerance alone is the cause of the symptoms.
Viewers share their comments
Lactose Intolerance - Symptoms Question: The symptoms of lactose intolerance can vary greatly from patient to patient. What were your symptoms at the onset of your disease?
Lactose Intolerance - Causes Question: When did you develop lactose intolerance?
Lactose Intolerance - Diet Question: What's it like to try the elimination diet? What were the results?
Lactose Intolerance - Treatment Question: What forms of treatment, including diet and supplements, have been effective for your lactose intolerance?