Written by Patrick B. Massey, MD, PH.D. There are fundamental problems with the food allergy tests themselves as well as the interpretation of the results.
You might be surprised to learn that food allergy testing, a common laboratory test done by both physicians and nontraditional practitioners, has almost no clinical validity.
It is no surprise that serious food allergies and less serious food sensitivities are more common than in the past. In an effort to determine which foods are causing reactions, health care providers have turned to food allergy testing. However, there are fundamental problems with the tests themselves as well as the interpretation of the results. These issues impact millions of people per year.
As a clinician, it seems that at least a third of my patients tell me they are allergic to one or more foods because someone tested them for food allergies. This has become one of the most common tests done in both traditional and nontraditional medicine.
Allergy testing can be ordered by medical physicians, chiropractors, nutritionists, naprapaths, physician assistants, nurse practitioners, nurses and even the patients themselves.
I cannot uncover any data to tell me how many food allergy tests are done every year, however the annual medical costs of treating all allergies including food allergies exceeds $20 billion.
Indeed, many patients who come to see me for their bowel issues often bring with them multiple tests for food allergies. The big question is, “do they accurately reflect a clinical issue?” And the answer, for most people, is no.
There are several methods for food allergy testing. The most popular way of assessing a food allergy is to measure whether or not the body is producing antibodies to the food.
If no antibodies are found, it is assumed that there is no food allergy (not true). If antibodies are present it is also assumed that a food allergy exists (also not true).
The most pressing problem concerning these tests is that the results often fail miserably at establishing validity. Validity is the cornerstone of any laboratory test consisting of reproducibility of the test and correlation between different testing laboratories. Reproducibility means that a specific sample, tested several times at the same laboratory, will yield basically the same result.
Studies have shown that many, not all, laboratories have poor reliability. Several studies have shown poor correlation between laboratories. The same sample tested at different allergy testing facilities yielded significantly different results. These results differed by 40 percent to 65 percent — almost the same as flipping a coin.
The immune system is dynamic and changes rapidly in response to the environment. Cooking, storage, preparation (spices, herbs) physically change food making the usual allergy testing inaccurate because food allergy testing is commonly done using raw food extracts.
Antibodies to raw food are quite different from those to cooked food. For example, people who have a reaction to boiled eggs rarely react to raw eggs. Widespread food allergy testing leads to (probably) unnecessary therapies, medications, herbs, supplements, more allergy testing and expense.
My experience is that simply changing the diet for awhile can reset the immune system and food sensitivities often resolve.
- Patrick B. Massey, MD, PH.D., is medical director for complementary and alternative medicine at Alexian Brothers Hospital Network and president of ALT-MED Medical and Physical Therapy, 1544 Nerge Road, Elk Grove Village. His website is www.alt-med.org.
Posted December 11, 2017.