Food Sensitivity Tests help identify trigger foods that may be contributing to various health issues. These tests analyze specific antibody reactions to different foods, providing insights into potential sensitivities. Three key immunoglobulins – IgG, IgG4, and IgA – are commonly measured in these tests.
IgG antibodies can activate the complement system, a part of the immune response that can trigger inflammation. High levels of IgG (class II or higher) may indicate an overload on receptors, driving inflammatory reactions. Conversely, low levels (class 0/I) suggest tolerance to a particular food. IgG food sensitivity testing is widely used, and foods triggering high IgG reactions can often be reintroduced into the diet after a period of elimination.
IgG4 antibodies, unlike IgG, typically act as “blocking antibodies” for IgE, another type of antibody involved in allergic reactions. IgG4 can prevent IgE from binding to its receptors, thus reducing the likelihood of an allergic response. High IgG4 levels might indicate a protective response rather than a sensitivity. However, independent increases in IgG4 can be associated with certain autoimmune conditions. In cases of elevated IgG4, further testing for IgE reactivity is recommended, and permanent removal of the trigger food from the diet might be necessary.
IgA antibodies, similar to IgG, can activate the complement system and contribute to inflammation. Serum IgA reactions to food triggers can indicate irritation in the gut lining. This differs from secretory IgA (sIgA), found in stool, which plays a protective role in the digestive system. Elevated serum IgA levels can be associated with allergies and asthma. Distinguishing between serum IgA and sIgA is crucial in interpreting food sensitivity test results.
