About Food Allergies

Unproven Diagnostic Tests

by Philippe Bégin, MD, University of Montreal

Some doctors and other health care providers may recommend tests that are not scientifically proven to be effective in diagnosing food allergies. The Guidelines for the Diagnosis and Management of Food Allergy in the United States, published by the National Institute of Allergy and Infectious Diseases (NIAID) specifically lists tests that are unproven and nonstandardized and are NOT RECOMMENDED for the diagnosis of food allergy, many of which are included in the list below.

Led by a panel of food allergy experts, and accepted by a coordinating committee of 34 professional organizations, federal agencies and patient advocacy groups, the Guidelines provide the most up-to-date clinical advice on caring for patients with food allergies.

Please note that this table only lists some of the more common tests that the NIAID and other experts deem to be unproven and experimental. If you have a question about any test not listed here, talk to your allergist.

In addition to their cost, these unproven tests can be risky. First, they may lead to false diagnoses, with the associated anxiety and useless strict avoidance diet.  Worst, they may lead truly allergic people to believe they are not allergic to certain foods, which could cause them to eat a food they are allergic to and have a life-threatening reaction.  

   

Applied Kinesiology (muscle testing)

     

What It Is:

  The test exposes a person to the suspected food by having them hold it or by bringing it close to the body. They then measure muscle strength by applying pressure to an extended arm.
     
What You Will Hear:   False claim: Muscles in the body are “sensitive” to anything that is harmful to it. A food allergen will make you weaker when you are close to it. Acupuncture or acupressure may be used to “cure” the food allergy.
     
Why It Doesn't Work:   There are no data to support this. Muscle “weakness” can be affected by the suggestion or distraction of the person doing the test. A study was done on patients highly allergic to wasp venom. Four specialists who do this test were not able to tell the difference between wasp venom and water when using muscle testing on the allergic patients.1
     
   

Cytotoxicity testing

     
What It Is   In this test, white blood cells are taken from a sample of the blood. The cells are put on slides that contain dried samples of foods a person could be allergic to. The slides are viewed under a microscope. Changes in the appearance of cells supposedly show an allergy to any of those foods. 
     
What You Will Hear   False claim: They will tell you that changes in the appearance of cells on the slide show that the food is harmful to your blood cells.

For example, it  may be pointed out that your T cells are not shaped like a T (which is normal); or may be worried about all those “bacteria” in your blood (which are in fact blood platelets—a normal part of your blood) and recommend avoiding the food and/or treatment with special drops.
     
Why It Doesn't Work   Changes to the appearance of cells upon exposure to allergens cannot be viewed with a microscope. Those changes can only be seen through a much more advanced technique that is only available in research labs.  So, the changes reported in this test are either not real or not related.
     
   

Electrodermal test (vega testing)

     
What It Is   This method uses a galvanometer (an instrument that detects and measures electric currents) to gauge your body’s resistance when you come in contact with a food allergen. The patient is asked to hold the food in one hand and electric current is measured. 
     
What You Will Hear   False claim: You may be told that the electromagnetic signature of the food will interfere with that of your body if it is harmful to you. Increased resistance to the electric current indicates that you are allergic to the food being tested.
     
Why It Doesn't Work   There is no science to support those claims. The number shown on the galvanometer is caused by the amount of contact and pressure applied by the technician. 
 
   

Nambrudipad’s Allergy Elimination Technique (NAET)
a.k.a. Natural Elimination of Allergy treatment (NEAT)

     
What It Is   NAET is a treatment based on acupuncture that is usually combined with pseudo-scientific testing methods using electrodermal testing or applied kinesiology. (see above) It was invented by Devi Nambrudipad a chiropractor and acupuncturist from California. The idea is to combine exposure to small amounts of the food with acupuncture sessions to “desensitize” the subject.
     
What You Will Hear   False claim: Nambrudipad claims that 95 percent of human illness is caused by some sort of allergy.  Allergens may be a wide variety of things, as well as more abstract notions such as emotions and colors.The theory of NAET proposes that these allergies can be eliminated by addressing the energy blockages through the use of acupuncture or acupressure.

Devi Nambrudipad says that she received an MD degree from University of Health Sciences Antigua (UHSA) in 2002. The California Medical Board does not list an active license for her, and it does not recognize medical degrees from UHSA as valid, listing it as a "disapproved" school since 1995.
     
Why It Doesn't Work   While not included in the NIAID Guidelines, these claims have no basis. "NAET clashes with the concepts of anatomy, physiology, pathology, physics, and allergy accepted by the scientific community. The story of its "discovery" is highly implausible. Its core diagnostic approach – muscle testing for "allergies" – is senseless and is virtually certain to diagnose nonexistent problems. Its recommendations for dietary restrictions based on nonexistent food allergies are likely to place the patient at great risk for nutrient deficiency, and, in the case of children, at risk for social problems and the development of eating disorders."
 
  -Dr Stephen Barret of Quackwatch which dispels false medical claims.
     
   

IgG/IgG4 testing

     
What It Is   This test checks a person’s blood for immunoglobulin G (IgG), an antibody created by your body to fight a certain allergenic food.
     
What You Will Hear   False claim: IgG antibodies are involved in inflammation and auto-immune diseases.  So avoiding foods targeted by IgG could cure Crohn’s disease, diabetes, depression, obesity, attention deficit disorder and many more diseases.
     
Why It Doesn't Work   Unlike IgE antibodies, which are responsible for allergies, IgG antibodies are found in both allergic and non-allergic people. IgG are the normal antibodies made by the body to fight off infections. The creation of IgG antibodies is thought to be a normal response to eating food. For example, IgG antibodies actually go up during successful research studies on food immunotherapy.
     
   

Hair analysis

     
What It Is   This test examines a person’s hair for its mineral content.
     
What You Will Hear   False claim: If a harmful food is eaten, it should show in the hair’s mineral makeup.
     
Why It Doesn't Work   Hair grows slowly (less than ½ an inch per month), so even hair closest to the scalp is several weeks old. That means hair is not a good measure for the current condition of the body. Regardless, there is no rationale for this test in relation to food allergies.
     
   

Pulse testing

     
What It Is   This test checks a patient’s pulse after they eat a food.
     
What You Will Hear   False claim: This test is based on the idea that, if you are allergic to a certain food, your pulse (the rate of your heartbeat) will go up after you eat that food.
     
Why It Doesn't Work   There is no scientific basis for this test. The increase in pulse rate is most likely a because of the person’s anxiety about the test.

 

Other unproven and non-standardized tests as noted by the NIAID include: Basophil histamine release/activation, Lymphocyte stimulation, Facial thermography, Gastric juice analysis, Endoscopic allergen provocation, Provocation neutralization, and Mediator release assay (LEAP diet).

These are not the only non-standardized and unproven tests for diagnosing food allergies. For a complete list, please consult the Guidelines.  If you have concerns or questions about any diagnostic method, contact the American Academy of Allergy, Asthma & Immunology (AAAAI).

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1 Ludtke R Complementary Therapy in Medicine 9:141, 2001.