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IgG food antibody testing

In the assessment of food intolerances the two most commonly used options in integrative medicine are elimination diets and IgG food antibody testing. They are both imperfect, each having their pros and cons, as illustrated by the following table. If a persons symptoms/signs/history suggest possible involvement of food intolerances I suggest a person does one or the other (occasionally both) depending on their situation and personal preferences.

	Elimination diets	IgG testing
Pro	Free High reliability for most commonly reactive foods Tests for non-immune mediated intolerances	Minimal effort involved Investigates 96 foods
Con	High effort/motivation required Only can investigate ~12 foods A person can’t make any other changes during test period	Cost (~ $250) Significant false positive & negative rate Must have been eating food in question

You can see a sample report of an IgG analysis online here. As with many tests I wouldn't recommend using just any lab which offers the test. One noted integrative medicine expert did experiments sending blood to several different labs offering IgG testing. He found results varied significantly and the lab he concluded was the most reliable and consistent was US BioTek. This is the lab I currently use. Levels of IgG (Immunoglobulin G) antibodies to specific foods are measured in blood as a measure of immune reactivity to the food in question. To quote US BioTek:

"IgG antibodies represent the most prevalent class found in the blood. It is produced after reimmunization, or secondary response to antigen. It is the primary mediator of the memory immune response. Often involved in Type III delayed hypersensitivity reactions, IgG forms an immune complex with the allergen. This antibody/antigen complex activates complement (a group of small proteins found circulating in the blood stream that are involved in the release of inflammatory mediators), and enhances phagocytosis by opsonization. The inflammatory process is gradual and may take anywhere from several hours to several days, which is why this type of reaction is termed, delayed. Although immune cells called macrophages dispose of these immune complexes immediately, they only have a finite capacity to do so. Excess antigen may saturate the macrophages capacity resulting in the prolonged circulation of complexes and their deposition into the body tissues. Depending on which tissues are involved, it is thought that these complexes may be implicated in many different conditions/symptoms."

"IgG antibodies represent the most prevalent class found in the blood. It is produced after reimmunization, or secondary response to antigen. It is the primary mediator of the memory immune response. Often involved in Type III delayed hypersensitivity reactions, IgG forms an immune complex with the allergen. This antibody/antigen complex activates complement (a group of small proteins found circulating in the blood stream that are involved in the release of inflammatory mediators), and enhances phagocytosis by opsonization. The inflammatory process is gradual and may take anywhere from several hours to several days, which is why this type of reaction is termed, delayed. Although immune cells called macrophages dispose of these immune complexes immediately, they only have a finite capacity to do so. Excess antigen may saturate the macrophages capacity resulting in the prolonged circulation of complexes and their deposition into the body tissues. Depending on which tissues are involved, it is thought that these complexes may be implicated in many different conditions/symptoms."

The IgG test is a useful test although it must be taken into account that it does have a significant false positive and false negative rate. It is far from 100% accurate. It provides a rough guide should not be read as definitive findings. Testing negative for a food (e.g. wheat) does not rule out the possibility of intolerance and testing positive for a food does not definitely mean this food is contributing to your symptoms.

If anyone in Australia/New Zealand would like to have this test done please send us an email and we can give you instructions on how to do the test and email you the results as soon as they come in.

Blake Graham, BSc (Honours), AACNEM
Clinical Nutritionist
Perth, Western Australia
Phone/Email: See Contact page
*Non-Perth residents may enquire about phone consultations.

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IgG food antibody testing

Elimination diets

IgG testing

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