Verbatim response from ChatGPT
Short answer: there is no single reliable commercial "food sensitivity" test for vague or delayed symptoms. Valid testing depends on the problem you suspect. For true allergies and specific conditions, use established medical tests done through a physician — not consumer IgG panels.
Recommended, evidence-based tests and who does them
- For suspected immediate (IgE-mediated) food allergy: skin prick testing (done in an allergy clinic) and serum specific IgE testing (ImmunoCAP by Thermo Fisher is the most widely used, run through labs such as Quest Diagnostics or LabCorp). These tests are clinically validated and interpreted by an allergist.
- For complex allergy patterns / cross‑reactivity: component‑resolved diagnostics (e.g., ImmunoCAP ISAC) can add useful detail in specialist care.
- For celiac disease: tissue transglutaminase IgA (tTG‑IgA) and total IgA (available from Quest, LabCorp). Positive serology → GI referral for confirmation.
- For lactose or fructose intolerance: hydrogen breath testing performed by gastroenterology clinics or testing centers (reliable for carbohydrate malabsorption).
- For non‑IgE, delayed reactions or suspected food‑triggered GI conditions (e.g., eosinophilic esophagitis, food protein–induced enterocolitis): diagnosis is by specialist evaluation (GI or allergy), endoscopy/biopsy when indicated, or supervised elimination diet followed by medically supervised oral food challenge. The double‑blind, placebo‑controlled food challenge is the gold standard for proving a food causes symptoms.
What to avoid
- IgG or IgG4 “food sensitivity” panels sold direct‑to‑consumer (Everlywell, Vibrant/Vibrant America, YorkTest and similar) are not supported by allergy/immunology societies. IgG often reflects exposure or tolerance, not harmful sensitivity, and acting on these results can lead to unnecessary, restrictive diets and missed diagnoses.
- ALCAT, MRT and many “mediator release” or cytotoxic panels lack high‑quality evidence and are not recommended by major professional groups.
Practical next steps
- If you have hives, lip/throat swelling, wheeze, syncope or immediate reactions: see an allergist for skin testing and/or ImmunoCAP sIgE.
- If you have chronic GI symptoms (bloating, diarrhea, pain): see a gastroenterologist for evaluation (including celiac testing and breath testing where appropriate) and a registered dietitian to do a structured elimination/rechallenge safely.
- If symptoms are vague/delayed: the safest, most reliable approach is an elimination diet under dietitian/clinician supervision followed by medically supervised reintroduction or, when needed, a formal food challenge.
If you want, tell me your symptoms and whether you’ve had prior tests; I can recommend the most appropriate next test and help you find the right specialist.