Myths vs facts: IgG and allergy

A common myth is that IgG antibody tests can reliably diagnose food allergies or intolerances. The fact is: IgG is a 'memory' antibody produced after normal food exposure and does not indicate an allergic reaction. True food allergies are mediated by IgE antibodies and typically manifest within minutes to hours. IgG tests are explicitly not recommended by major allergy organizations such as the European Academy of Allergy and Clinical Immunology (EAACI) and the American Academy of Allergy, Asthma & Immunology (AAAAI), because they lead to false diagnoses and unnecessary dietary restrictions. The evidence is strong: numerous studies show that IgG levels correlate with tolerance, not allergy. Some labs market IgG tests for 'delayed' intolerances, but the scientific basis is lacking. Consumers should rely on validated methods like IgE testing, skin prick tests, or physician-supervised elimination diets. Results from MyBody-X or other genetic tests cannot predict IgG responses. Beware of overblown claims: IgG testing is not a substitute for proper allergy evaluation.