Myths vs facts: IgG and Sport

The claim that IgG (immunoglobulin G) tests help athletes identify food intolerances and improve performance is not supported by scientific evidence. IgG is a memory antibody produced after repeated exposure to foods; its presence indicates immune exposure, not intolerance or allergy. Major medical societies (e.g., DGAKI, EAACI) advise against using IgG-based tests for diagnosing food sensitivities, as they often lead to unnecessary dietary restrictions and nutrient deficiencies. In sports nutrition, no robust randomized controlled trials show performance benefits from IgG-guided elimination diets. The evidence is limited to mechanistic reasoning and small, often biased observational studies. Fact: a well-balanced, individually tailored diet with adequate carbohydrates, protein, and micronutrients enhances performance – IgG tests do not provide a reliable basis for such planning. Athletes should rely on proven methods like professional dietary counseling, food-symptom diaries, and, if needed, IgE allergy testing.