IgG Unverträglichkeitstest: which blood markers matter?

IgG intolerance tests measure IgG antibodies against foods in the blood. The premise that elevated IgG levels indicate delayed food intolerance lacks scientific validation. Professional bodies such as the European Academy of Allergy and Clinical Immunology (EAACI) advise against these tests because IgG antibodies often reflect normal immune exposure to common foods and do not correlate reliably with clinical symptoms. The measured markers (e.g., IgG1–4 against specific proteins) are therefore not valid for diagnosing intolerance. For suspected true food intolerances (e.g., lactose intolerance, fructose malabsorption) or allergies (IgE-mediated), evidence-based methods such as breath tests, elimination diets, or specific IgE testing should be used. These tests frequently lead to unnecessary dietary restrictions and nutrient deficiencies. Evidence: marketing. Sources: none from the given context.