Verbatim response from ChatGPT
Short answer: there isn't a single validated commercial "food sensitivity" blood test for general symptoms — many direct‑to‑consumer IgG panels are not supported by evidence and should be avoided. The best approach is to get the specific, evidence‑based tests that match what you suspect (allergy, celiac disease, or an intolerance) and/or a supervised elimination/rechallenge.
What to use instead (by situation)
- Suspected immediate allergy (hives, throat tightness, anaphylaxis, wheeze): see a board‑certified allergist for skin‑prick testing and/or serum specific IgE testing using ImmunoCAP (Thermo Fisher/Phadia). These tests are run by major labs (Quest Diagnostics, LabCorp) and are clinically validated. The allergist can also perform a supervised oral food challenge (the gold standard) if needed.
- Suspected celiac disease (diarrhea, weight loss, iron deficiency, family history): order tissue transglutaminase IgA (tTG‑IgA) plus total IgA (and possibly deamidated gliadin peptide tests) through reputable labs such as Quest or LabCorp. HLA‑DQ2/DQ8 typing can be useful in select cases.
- Suspected lactose, fructose intolerance or SIBO (bloating, gas after eating): get a medically supervised hydrogen (and/or methane) breath test — available via gastroenterology clinics and some labs. A gastroenterologist can interpret results and recommend treatment.
- Non‑allergic, non‑celiac symptoms (chronic GI upset, fatigue, vague symptoms): the best validated method is a structured elimination diet with a registered dietitian and, if needed, blinded food challenges (double‑blind placebo‑controlled food challenge is the research gold standard). This avoids false positives from unproven blood panels.
What to avoid
- IgG food‑sensitivity panels sold direct to consumers (Everlywell, Vibrant Wellness, Cyrex, YorkTest, many others). Major allergy societies (AAAAI, BSACI and others) state IgG antibodies typically indicate exposure—not harmful sensitivity—and using those results to eliminate foods can be misleading and nutritionally harmful.
Practical next steps
- Clarify your main symptoms (allergic reactions vs digestive symptoms vs general fatigue/aches). I can help with that if you describe them.
- If allergy‑type symptoms: book an appointment with an allergist for skin testing/ImmunoCAP and possible challenge.
- If GI symptoms: see a gastroenterologist for breath testing or celiac serology.
- If unclear: work with a registered dietitian for a supervised elimination/rechallenge plan.
If you want, tell me what symptoms you have and whether you’ve already tried any tests — I can suggest the most appropriate next test or specialist and help you find a local provider or lab.