5Strands

Short answer: there isn’t a single reliable “food sensitivity” blood test that proves foods are causing vague symptoms. Tests that are evidence‑based depend on what you mean by “sensitivity.” For accurate, clinically useful testing, see an allergist or gastroenterologist and use these validated tests/procedures rather than consumer IgG panels. What is evidence‑based (and when to use it) Immediate (allergic) reactions — hives, swelling, throat tightness, anaphylaxis: Skin‑prick testing by a board‑certified allergist and/or serum specific IgE testing (ImmunoCAP/Phadia by Thermo Fisher via labs such as Quest or LabCorp). These are the appropriate, validated tests for IgE‑mediated food allergy. Celiac disease (gluten‑related autoimmune disease): Tissue transglutaminase IgA (tTG‑IgA) plus total IgA (and sometimes EMA or HLA DQ2/DQ8). Available at major clinical labs (Quest, LabCorp). Don’t start a gluten‑free diet before testing. Carbohydrate intolerances: Lactose, fructose, small intestinal bacterial overgrowth: hydrogen/methane breath tests performed by GI clinics (standard clinical breath testing equipment such as QuinTron analyzers are commonly used in practice). Non‑IgE, delayed reactions or “intolerances”: The best approach is a medically supervised elimination diet followed by structured re‑introduction and, if needed, a supervised oral food challenge (single‑ or double‑blind). Double‑blind placebo‑controlled food challenge (DBPCFC) is the research gold standard and the clinical oral food challenge is the practical standard. What to avoid (the “scam” tests) IgG or IgG4 food panels sold direct‑to‑consumer (Everlywell, Vibrant Wellness / Vibrant America, YorkTest, 5Strands, many others). Major allergy societies (AAAAI, EAACI) and expert reviews conclude IgG food testing is not reliable for diagnosing food intolerances or allergies — positive IgG usually just indicates exposure, not disease. Using these tests often leads to unnecessary, overly restrictive diets. Practical recommendation (stepwise) If you’ve had immediate allergic symptoms or anaphylaxis: see an allergist now for skin testing and/or ImmunoCAP specific IgE testing. If you have chronic GI symptoms (bloating, diarrhea, IBS‑type): see a gastroenterologist. Consider hydrogen breath testing for lactose/fructose/SIBO and testing for celiac (tTG‑IgA via LabCorp/Quest). For diffuse, unclear “sensitivity” (fatigue, headaches, skin problems without clear allergy): work with a registered dietitian (RD) experienced in food reactions to do a targeted elimination and reintroduction. If needed, have supervised oral food challenges. Avoid paying for IgG panels; they’re not supported by evidence and often cause harm by prompting unnecessary elimination. If you want specific providers/products to use: Allergy testing: board‑certified allergist; specific IgE testing via ImmunoCAP (Thermo Fisher) run on major labs (Quest, LabCorp). Celiac testing: tTG‑IgA (Quest Diagnostics, LabCorp). Breath testing (lactose/fructose/SIBO): performed at GI clinics using standard clinical breath analyzers (ask your GI clinic which equipment/protocol they use). Diet guidance and elimination challenges: registered dietitians specializing in food allergies/IBS (many practices and hospital nutrition departments offer this). If you tell me your main symptoms (immediate hives/anaphylaxis vs bloating/diarrhea vs chronic fatigue/eczema), I can recommend the exact test and next step for your situation.

Mentioned in position 7 of 7