Add-On: IgG Spices

IgG antibodies to food antigens reflect class-switched adaptive immune responses that may occur after repeated exposure. Spices contain complex proteins, alkaloids, and polyphenols that can elicit IgG production, though the biological significance of such antibodies in the absence of IgE-mediated allergy or coeliac-type pathology remains contested.

Elevated IgG to black pepper or other spices is interpreted within functional and integrative frameworks as a marker of immune activation or tolerance loss, potentially linked to gastrointestinal permeability or chronic low-grade inflammation. Mainstream allergy and immunology societies do not endorse IgG food testing for diagnosis of food allergy or intolerance.

Cayenne and other Capsicum species contain capsaicinoids and antigenic proteins that can provoke IgG responses, particularly with frequent consumption or in the context of increased intestinal permeability.

Reactivity patterns are used in integrative practice to guide personalised elimination diets, though evidence that IgG-driven responses cause symptoms is limited and mechanistically debated.

Cinnamon proteins and polyphenolic compounds can stimulate IgG production; true IgE-mediated cinnamon allergy is rare but documented, whereas IgG responses are more commonly detected in food-sensitivity panels.

Elevated IgG is interpreted as a marker of immune exposure rather than clinical allergy; relevance to symptoms is determined by elimination-rechallenge and clinical correlation.

Clove (Syzygium aromaticum) contains eugenol and antigenic proteins that may elicit IgG responses, particularly in individuals with altered gut barrier function.

Used in functional medicine to identify potential dietary triggers of non-specific gastrointestinal or systemic symptoms.

Coriander (cilantro leaf) proteins can provoke IgG responses; some individuals report taste aversion or gastrointestinal discomfort, though the role of IgG in such reactions is unclear.

Measured to complete the spice-reactivity profile in integrative elimination protocols.

Cumin seed proteins can elicit IgG; cuminal and other volatile compounds are less likely to be immunogenic but contribute to the overall antigenic load.

Part of a comprehensive spice panel; clinical significance depends on symptom correlation and response to elimination.

Garlic (Allium sativum) contains multiple allergenic proteins, some heat-stable; IgE-mediated garlic allergy is documented but rare, whereas IgG responses are more frequently detected on food-sensitivity panels.

Elevated IgG to garlic is explored in integrative practice as a possible contributor to gastrointestinal or inflammatory symptoms, though causality is not established.

Ginger rhizome proteins and gingerols can provoke IgG responses; ginger is widely consumed for its anti-inflammatory and digestive properties, yet some individuals mount IgG responses with uncertain clinical meaning.

Included in spice panels to identify potential immune reactivity; clinical significance is assessed through dietary manipulation and symptom tracking.

Mustard seed proteins are well-characterised IgE allergens (particularly Sin a 1), and mustard is a priority allergen in European labelling; IgG responses are common and may reflect tolerance or ongoing low-grade activation.

Elevated IgG does not diagnose IgE-mediated mustard allergy but is used in functional protocols to guide trial elimination.

Turmeric (Curcuma longa) proteins and curcuminoids can elicit IgG; turmeric is increasingly consumed as a supplement and food ingredient, raising exposure and the potential for immune recognition.

Reactivity to turmeric is assessed in integrative practice, particularly in patients consuming high-dose curcumin supplements, to explore whether immune responses contribute to paradoxical symptoms.