Understanding IgG Food Allergy Testing
IgG Food Sensitivity Testing: Clinical Uses, Evidence & Practical Steps
By Lauren Russel, ND, and Leah Alvarado-Paz, ND • Published in Townsend Letter
Food reactions can drive chronic issues ranging from migraines and eczema to IBS and autoimmune conditions. While IgE-mediated allergies (immediate, potentially life-threatening) are well recognized, many adverse responses are delayed and involve IgG antibodies—often missed by conventional workups.
Actionable insight: IgG-guided elimination and rotation diets frequently reduce symptom burden and improve quality of life in appropriately selected patients.
The Four Types of Food-Related Immune Reactions
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- Type I (IgE-mediated): Immediate reactions; can include anaphylaxis.
- Type II: Antibody-driven cell damage.
- Type III: IgG-mediated immune complexes with delayed onset inflammation.
- Type IV: T-cell-mediated; implicated in autoimmune gut disorders (e.g., celiac disease).
IgG (Especially IgG4) Testing: Where It Fits Clinically
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Though debated in mainstream settings, IgG/IgG4 panels are increasingly used in functional and integrative practice. Elevated IgG does not equal “allergy,” but it can correlate with symptoms and help prioritize foods for structured elimination and re-challenge.
- Children: Patterns of IgG may precede IgE allergy; links noted with chronic diarrhea and even obesity in inflammatory contexts.
- Migraine: IgG-guided diets have reduced attack frequency and medication reliance in studies.
- IBS: RCTs show symptom improvement with IgG-based elimination; symptoms often recur upon reintroduction.
Celiac Disease vs. Non-Celiac Gluten Sensitivity
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Celiac disease is an autoimmune condition confirmed by serology and biopsy. Many symptomatic patients lack celiac markers yet still react to gluten; IgG testing can help flag non-celiac gluten sensitivity and guide a supervised dietary trial.
Testing Methods at Meridian Valley Lab
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- Assay: ELISA-based serum and blood-spot IgG/IgG4 panels.
- At-home collection: Blood-spot kits covering ~45–95 food antigens.
- Reporting: Results grouped as safe, moderate, or avoid to drive personalized elimination and rotation plans.
Practical Workflow: From Test to Table
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- Baseline: Collect history (GI, skin, neuro, autoimmune), meds/supplements, and diet log.
- Test: Order IgG/IgG4 panel; consider adding gut and inflammatory markers if indicated.
- Eliminate: Remove “avoid” foods 4–6 weeks; keep nutrient density high.
- Re-challenge: Reintroduce one food at a time while tracking symptoms (48–72 hours).
- Maintain: Build a rotation plan; address gut barrier, microbiome, and lifestyle drivers.
Important Interpretation Notes
IgG ≠ IgE allergy: MVL’s IgG panels indicate immune reactivity, not immediate-type allergy. Results must be interpreted by licensed clinicians within the context of history, exam, and other labs. For suspected anaphylaxis, pursue standard IgE testing and emergency planning.
Ready to Take the Next Step?
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Patients: Ask your licensed provider about MVL’s IgG Food Sensitivity Test and whether an elimination–re-challenge plan is right for you. Meridian Valley Lab provides laboratory services only and cannot advise patients directly.
Practitioners: Contact Client Services for panels, kits, and interpretation support.
Call: 855.405.8378 | 206.209.4200
Test Your Food Sensitivities at Home
Order your FoodSafe™ IgG4 (190) kit directly from our shop and collect your sample at home.
