The IgG Food Antibody Assessment is a blood test that measures antibodies to 87 commonly consumed foods. The panel also includes a total IgE measurement. The body can react to foods in many different ways. Adverse food reactions can lead to distressing symptoms and chronic health conditions. Often times it is unknown exactly which food(s) may be the cause and testing can help identify the problematic foods. Removal of the reactive foods often results in resolution of symptoms.
What is the difference between IgE and IgG-mediated reactions?
The key differences between IgE allergies and IgG sensitivities are summarized below:
(Foods, molds, inhalants)
(Foods, spices, vegetarian foods)
|Immediate onset (minutes to hours)||Delayed onset (hours to days)|
|Circulating half-life of 1-2 days||Circulating half-life of 21 days|
|Permanent allergies||Temporary sensitivities|
|Stimulates histamine release||Activates complement
Does not stimulate histamine release
|Hives, stuffy or itchy nose, sneezing, itchy, teary eyes, vomiting, stomach cramps or diarrhea, angioedema or swelling, shortness of breath or wheezing, anaphylaxis||Gastrointestinal symptoms, headaches, joint aches, rashes, other vague symptoms|
When should testing for IgG Food Antibodies be considered?
Testing for adverse food reactions is useful for individuals who suspect that a food is responsible for causing their symptoms but can’t quite identify which food(s). The presence of circulating antibodies may affect each patient differently. Circulating IgG food antibodies are not diagnostic for a specific condition but indicate an immune response to that food. The immune response could be a normal response that would not necessarily cause symptoms. Therefore, test results should always be viewed in the context of the overall clinical picture. The role of IgG food antibody testing is still being researched, however, studies have shown the benefit of testing in certain conditions.1
Conditions associated with IgG food sensitivity
- Irritable Bowel Syndrome (IBS)2-4
- Major Depressive Disorder4
- Migraine headaches5-7
- Skin rashes such as eczema8
- Joint aches9
- Autoimmune disease10
- Crohn’s Disease11
The “Leaky Gut” Connection
The presence of circulating IgG antibodies to foods may be suggestive of increased intestinal permeability, also referred to as “leaky gut syndrome.” When the tight junctions forming the barrier in the gut don’t work properly, larger substances can “leak” through, causing an immune response. This immune response may result in the production of IgG antibodies to foods.4 There are multiple dietary and lifestyle factors that contribute to increased intestinal permeability. These factors include alcohol,13 stress,14,15 chronic NSAID use,16 Western-type diet (high consumption of red meat, animal fat, high sugar, and low fiber food),17 and prolonged and strenuous exercise.18-20