Immunoglobulin G (IgG)


The results of food intolerance testing will provide information about your immune system and whether it is in conflict with various components of your diet.



We’re all familiar with rapid acting food allergies, such as those caused by peanuts, or shellfish, and if you have that type of allergy, you almost certainly know about it already. This test does not measure the rapid reactor type of antibody, called IgE (immunoglobulin E). Instead, the FoodSafe test measures a class of slower reacting antibodies called IgG4 (immunoglobulin G4). IgG is the most common type of antibody in the blood, reactions to eaten food of which are indicative of slower-type food intolerances.




Antibodies are major components of humoral immunity (immunity mediated by macromolecules—as opposed to cell-mediated immunity—found in the humors, or bodily fluids). IgG is the main type of antibody found in blood and extracellular fluid, controlling infection of body tissues (Junqueira et al, 2003). Representing approximately 75% of serum antibodies in humans, IgG is the most common type of antibody found in the circulation. By binding many kinds of pathogens such as viruses, bacteria, and fungi, IgG protects the body from potential threats—and neutralizes toxins. 





Food specific IgG4 levels increase in response to food antigens in the bloodstream. Not surprisingly, increased IgG4 levels are most often associated with foods eaten regularly, such as dairy, wheat, and eggs. IgG4 responses to foods often cause delayed symptoms, including, but not limited to, joint or muscle pain, chronic low back pain, bedwetting, recurrent bladder or upper respiratory infections, chronic headaches, fatigue, hives, eczema, psoriasis, canker sores, ulcerative colitis, gallbladder attacks, heartburn, and indigestion. Since IgG4 reactions often occur hours or days after particular foods are consumed, they can be difficult to recognize and correlate to the offending food. The reactions can be subtle or severe, and if not identified and eliminated, may lead to chronic symptoms and chronic degenerative conditions.