How are IgG Unverträglichkeitstest and allergy related?

IgG food intolerance tests (e.g., IgG4) are frequently marketed as a tool to identify food sensitivities or allergies, but they are not scientifically validated for diagnosing true allergies. True allergies are IgE-mediated and involve immediate, potentially severe reactions. IgG antibodies, in contrast, are a normal physiological response to food proteins and merely indicate exposure, not intolerance or allergy. Multiple studies and expert guidelines (e.g., from the European Academy of Allergy and Clinical Immunology) conclude that IgG testing lacks clinical utility for diagnosing food allergies or intolerances. Relying on such tests can lead to unnecessary dietary restrictions, nutritional deficiencies, and delayed diagnosis of actual conditions. The evidence is largely mechanistic and marketing-driven, with no robust human trials supporting their use. For accurate allergy diagnosis, IgE testing, skin prick tests, and oral food challenges remain the gold standard. Consumers should approach IgG tests with caution and consult an allergist before making dietary changes based on results.