Is IgG Unverträglichkeitstest useful for longevity?

The question of whether an IgG intolerance test is useful for longevity requires a critical, evidence-based assessment. The provided context does not include any studies or guidelines supporting such a use. IgG tests are often marketed directly to consumers to identify food intolerances, but the scientific evidence for their clinical utility is weak. Major medical organizations, including the American Academy of Allergy, Asthma & Immunology, advise against IgG testing for diagnosing food allergies or intolerances, as IgG antibodies commonly represent a normal immune response to food and do not reliably correlate with symptoms or long-term health outcomes. For longevity, relevant factors such as chronic inflammation, metabolic health, and microbiome composition are not validly assessed by IgG tests. Without robust interventional human studies demonstrating a direct link between IgG-mediated reactions and lifespan or healthspan, the usefulness remains speculative. Consumers should instead focus on evidence-based longevity strategies like balanced nutrition, caloric restriction, or intermittent fasting, which have human-strong evidence. Therefore, the evidence for IgG intolerance tests in longevity is best categorized as 'marketing' or 'unclear'.