Elevated antibody levels can be clinically significant — while the antibodies themselves don’t destroy anything, they do trigger an inflammatory response that can cause significant destruction of tissue and resulting symptoms. This response is not necessarily dependent on antibody levels. However, an equivocal result may mean you are just beginning to exhibit an immune reaction, so this is an important time to take measures to support the body in damping immune reactivity.

How useful is this test?

Immunoglobulin G (IgG) food testing is a useful guide for structuring elimination diets for people with many chronic conditions. Individuals with neurological, gastrointestinal, movement, and behavioral disorders often suffer from IgG food sensitivities. People may continue to eat offending foods unaware of their potential adverse effects.

The clinical significance of IgG food testing was illustrated in an early article published by an otolaryngologist who reported that the majority of his patients had substantial health improvements after eliminating foods found positive by IgG food allergy testing. The study demonstrated a 71% success rate for all symptoms, achieving at least a 75% relief. Of particular interest was the group of patients with chronic, disabling symptoms, unresponsive to other intensive treatments. Symptoms most commonly improved (75%-100%) on the elimination diets included asthma, coughing, ringing in the ears, chronic fatigue, headaches, gas, bloating, diarrhea, skin rash and itching, and nasal congestion.

The most common IgG food allergies were to cow’s milk, garlic, mustard, egg yolk, tea, and chocolate. A recent study reported that 93% of non-celiac, gluten-sensitive patients showed anti-gliadin IgG antibody disappearance after a six-month adherence to a gluten-free diet.

The IgG disappearance was closely related to a significant improvement of both gastrointestinal and extra-intestinal symptoms. High IgG antibody levels have frequently been found in children with diabetes mellitus, Crohn’s disease, celiac disease, and in those considered to be obese.

IgG versus IgE

Symptoms associated with food sensitivities may occur hours or days after the offending food was eaten because IgG food antibodies remain for a much longer time than IgE antibodies. IgE food allergy causes the release of histamine, producing an immediate hypersensitivity reaction. In contrast, IgG food sensitivity is triggered by the binding of complement to IgG food antigen complexes, causing an inflammatory response. This is a delayed hypersensitivity reaction in which symptoms appear anywhere from hours to days after eating the offending food.

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