What does the Immunoglobulin G Antibodies to Food Antigens test measure?

Why is Immunoglobulin G Antibodies to Food Antigens measured?

The panel quantifies IgG antibodies to 96 common foods, spanning dairy, grains, meats, seafood, fruits, vegetables, nuts, seeds, legumes, and spices. Proponents use elevated IgG titres to guide elimination diets in patients with unexplained gastrointestinal symptoms, fatigue, or chronic inflammatory conditions. However, major allergy societies caution that IgG to foods is a marker of exposure, not disease, and that elimination based solely on IgG results may lead to unnecessary dietary restriction without proven clinical benefit.

Reference ranges

Standard reference

Laboratory-specific thresholds classify reactivity as normal, borderline, moderate, or high; intervals are proprietary to the testing platform.

Functional medicine optimal

The concept of an 'optimal' IgG titre is not established in mainstream immunology; results are typically reported as reaction strength (normal/borderline/moderate/high) relative to the laboratory's reference population rather than as absolute thresholds with proven clinical endpoints.

Units

U/mL, standardised units

Reference ranges vary by laboratory and assay platform. Interpret in context of the issuing laboratory's stated range.