What should I know about IgG Unverträglichkeit Test?

IgG food intolerance tests (often measuring IgG4) are commercially marketed but lack scientific validation. Major allergy and immunology societies – including the European Academy of Allergy and Clinical Immunology (EAACI) and the German Society for Allergology (DGAKI) – explicitly advise against their use. The reason: IgG antibodies to food proteins are a normal physiological response to dietary exposure; their presence does not indicate intolerance or allergy. Controlled studies have found that healthy individuals also produce IgG to many foods, and test results do not reliably predict symptoms. These tests are costly, may lead to unnecessary dietary restrictions, and can delay diagnosis of genuine conditions like celiac disease or IgE-mediated allergies. If you suspect a food-related problem, evidence-based approaches (symptom diary, elimination diet under supervision, validated allergy tests, breath tests for lactose/fructose) are recommended. Evidence grade: mechanistic/unclear – the underlying concept is plausible but not supported by clinical outcome data. Caveat: no single test can replace a thorough medical workup.