Some tests are not recommended or not proven to be effective in diagnosing food allergies. These tests may give inaccurate or misleading results. They can be expensive, lead to an inaccurate food allergy diagnosis, or worse, miss a food allergy.
Knowing which tests are unproven may save you time and money. If your doctor suggests an unproven test, talk with them. Ask them why they recommend these tests. You can always get a second opinion.
The type of tests unproven for diagnosing food allergies include:1,2
- IgG/IgG4 testing
- Hair analysis
- Electrodermal testing
- Cytotoxicity testing
- Muscle testing
- Pulse testing
- Nambudripad’s allergy elimination techniques
IgG/IgG4 testing
Blood tests for IgE antibodies can be helpful in diagnosing a food allergy. However, blood tests for IgG and IgG4 antibodies are unproven. The problem is that IgG antibodies are found in both people who have allergies and those who do not.1
IgG antibodies are thought to be made as a normal response to eating food. A positive IgG test does not mean you are allergic to a possible allergen. It just means that your immune system has “seen” that food allergen before.1
Hair analysis
In this test, strands of hair are examined for their mineral content. The theory is that if a food allergen is eaten, it will show up in the mineral makeup of the hair. However, there is no reasoning behind this. Hair grows very slowly, so even hair close to the scalp is several weeks old. This makes hair analysis poor test for a food allergy.1
Electrodermal (vega) testing
Electrodermal testing (ET) measures the body’s ability to conduct an electrical current when it comes in contact with a certain food. The idea is that if you are allergic to a food, your ability to conduct electricity will drop. There is no science to support this theory.1,2
Cytotoxicity testing
This test takes your white blood cells and puts them on a slide with dried samples of foods you might be allergic to. The slides are studied under a microscope to look for changes in your white blood cells. However, cellular changes can only be seen with advanced equipment, not a microscope. Any changes reported with this test are either not real or not related to a food allergy.1
Muscle testing
Muscle testing is also known as applied kinesiology. With this test, you are asked to hold a food or bring it close to your body. Muscle strength is then measured. There is no scientific data to support this test.1
Pulse testing
This test checks your pulse before and after eating a food. The idea is that your pulse (heartbeat) goes up after eating a food you are allergic to. If someone’s pulse does go up during this test, it is most likely related to test anxiety.1
NAET
NAET stands for Nambudripad’s Allergy Elimination Techniques. It may also be called Natural Elimination of Allergy Treatment (NEAT). NEAT combines acupuncture with electrodermal or muscle testing. Regardless of the name, this test is considered useless by national allergy associations.1
Other dubious tests
Other tests that are not effective include:1
- Lymphocyte stimulation
- Facial thermography
- Gastric juice analysis
- Endoscopic allergen provocation
- Mediator release assay
- Basophil histamine release/activation
- Provocation neutralization
For more information, the Guidelines for the Diagnosis and Management of Food Allergy in the United States lists food allergy tests to avoid.