The Chicago Tribune recently ran an article (Doubts Cast on Food Intolerance Testing) which claims that “food allergy testing” does not help with digestive issues, fatigue, etc.
There is a long history of confusion around food allergies. There are fraudulent practices associated with testing: labs that produce invalid data, unreproducible data, and those that use methods that have been shown to have little scientific value. All physicians should discourage testing that is clearly scientifically invalid and should support lab quality control verification.
It is right and appropriate for the medical community to discourage medical testing that has been shown to be of no value, especially when it adds risk (such as x-rays). But the focus of the medical community should be on finding real solutions to patient problems. Rather than painting all food allergy issues that fall outside the typical allergists emphasis as unscientific, we encourage physicians to separate the valuable scientific evidence from the fraudsters, bad labs, and clearly bogus claims.
Allergy specialists groups have recently redefined allergy as only IgE reactions that exclude symptoms other than asthma, eczema, hives, rashes, and anaphylaxis within a short time after exposure.
This is a political, not a scientific choice.
There is no research that demonstrates that food allergies (immune system reactions to allergens) cannot produce other symptoms and there are many studies that demonstrate that even immunoglobulin Type E reactions can be delayed and produce a wide variety of symptoms. Thus some recent statements made by physicians and physicians groups in the press concerning food allergies must be understood to contradict the best available scientific evidence.
The more traditional, scientific definition of allergy includes all situations wherein the patient’s body produces antibodies that bind to a substance and exposure to that substance causes the adverse reaction while eliminating exposure reduces or eliminates the symptoms, regardless of time frame.
The gold standard of medical science is the double-blind, placebo-controlled study. Such studies have demonstrated that immunoglobulin type G (IgG) antibodies to foods indicate allergies that can produce symptoms such as migraine headaches. Other studies have demonstrated that such allergies can produce IBS-type digestive symptoms and other symptoms.
Celiac disease is an allergy to the gliadin protein in gluten and is mediated by immunoglobulin type A and often IgG as well. Thus the evidence indicates that elevated antibodies of types other than IgE correlate with a state of allergy that results in symptoms that can be eliminated by ending the exposure.
Claims that IgG antibodies are produced by everyone on exposure to any food, or that the presence of these antibodies indicates tolerance are not supported by published research. We should, as a medical community, follow up on the studies that have demonstrated the value of identifying atypical food allergies through reliable, repeatable lab testing and learn more about these issues.
There is already enough scientific evidence to demonstrate that food allergies can cause migraines, IBS, and many other conditions. There is already enough evidence to demonstrate that food allergies may be mediated by non-IgE antibodies. Let’s focus on increasing our understanding so we can find the best ways to test patients and treat them.
Article Courtesy: Dr. Stephen Wangen