What is Onion and Why Does the Food Zoomer Test for It?

Allium-derived food antigen

Onion refers to proteins and peptides from Allium species that can interact with the immune system when eaten. Measuring IgA and IgG responses to onion proteins provides insight into mucosal and systemic immune patterns that may relate to digestive comfort, skin reactions, or food-related symptoms.

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Onion

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About Onion

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About Onion

Overview and History

Onion (Allium cepa) biomarkers represent food-derived proteins and peptides found in a common culinary plant. Biochemically, these markers include protein antigens and associated plant components (e.g., lectin-like proteins and small fermentable carbohydrates) that can be recognized by the human immune system when consumed. Clinically, onion has long been studied as a food that can trigger immune and non-immune responses in some people. Testing at the peptide level helps separate specific antibody reactivity to onion proteins from other pathways (such as carbohydrate fermentation), providing clearer data for interpretation within a broader food-sensitivity profile.

Interpreting Highs and Lows

Elevated IgA and/or IgG responses to onion suggest measurable immune recognition of onion proteins. Elevated IgA may point to activity at the mucosal surface (gut), while IgG elevations can reflect systemic antibody contact; either pattern can appear alongside other food or domain-specific responses in the panel. Interpretation depends on the full Food Zoomer report, symptom history, and other measured foods. Low or absent antibody responses suggest a lack of measurable immune recognition of onion proteins. Low levels do not exclude other non-antibody mechanisms (for example, fermentable carbohydrates or enzymatic intolerance) and should be weighed against clinical symptoms and the rest of the test results.

Featured Test

Onion is included in Food Zoomer to assess antibody responses to a widely consumed food that can contribute to clustered immune patterns. Evaluating IgA and IgG to onion proteins helps clinicians identify whether onion is part of a broader food-reactivity pattern, supporting targeted dietary planning and phased reintroduction strategies.

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Onion FAQs

What is Onion and why is it important?

Onion in this test refers to the proteins and peptides from the common Allium vegetable that can be recognized by the immune system. Measuring antibody responses helps show whether the body has mounted a mucosal or systemic response to onion. That information can clarify whether onion is part of a pattern of food-related immune activity affecting symptoms.

What does it mean if my Onion levels are low?

Low onion antibody levels mean the test did not detect a measurable IgA or IgG response to onion proteins. This suggests immune recognition of onion is unlikely to be a major driver of antibody-mediated symptoms, but it does not rule out non-antibody causes (such as carbohydrate sensitivity) or symptom triggers from other foods in your report. Always interpret low results alongside the full panel and clinical history.

What does it mean if my Onion levels are high?

High antibody levels to onion indicate measurable immune recognition and can reflect mucosal (IgA) or systemic (IgG) activity. Elevated results are an association that may help explain patterns of food-related symptoms when seen with other reactive foods; they require interpretation in the context of symptoms, timing, and the complete Food Zoomer report.

Why is Onion included in the Food Zoomer?

Onion is a common dietary ingredient that can appear in clustered food-response patterns. Measuring IgA and IgG to onion proteins helps providers detect whether onion contributes to mucosal or systemic antibody activity, refine elimination or reintroduction plans, and support more precise nutrition strategies.

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