A recent request from a patient for food sensitivity testing led to a bit of an investigation into the current practice of food sensitivity/intolerance/allergy testing, especially in the setting of direct-to-consumer marketing through pharmacies and community labs.
For those who like to get their information from our “national newspaper” (the Globe and Mail), a 2012 article titled Test for food allergies, sensitivities a 'waste of money,' doctor says is certainly of interest (the title gives you the gist of the article; visit our Quick Links section to read the short piece in full).
During our investigation, we also got some information from Dr. Michael Cyr, Professor, Division of Clinical Immunology & Allergy at McMaster University. Dr. Cyr pointed us to a statement by the Canadian Society of Allergy and Clinical Immunology (CSACI) released around the same time as the 2012 article mentioned above. To paraphrase, the CSACI believes that food-specific immunoglobulin G (IgG) testing "plays no role in the diagnosis of food allergy or intolerance" and you can read the statement by visiting the link listed in the Quick Links section.
In their statement paper, the CSACI goes on to address that, besides the fact there is a lack of research that supports the use of the IgG test to diagnose adverse reactions to food, there is a very serious and particular harm that IgG testing can play: A person with a true immunoglobulin E (IgE)-mediated food allergy, who is at significant risk for life-threatening anaphylaxis, may very well not have elevated levels of specific IgG to their particular allergen, and may be inappropriately advised to reintroduce this potentially deadly item into their diet.