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.
- Anderson S, Wakeley P, Wibberley G, et al. Development and evaluation of a Luminex multiplex serology assay to detect antibodies to bovine herpes virus 1, parainfluenza 3 virus, bovine viral diarrhoea virus, and bovine respiratory syncytial virus, with comparison to existing ELISA detection methods. J Immunol Methods 2011;366:79-88.
- Gimenez-Lirola LG, Jiang Y-H, Sun D, et al. Simultaneous Detection of Antibodies against Apx Toxins ApxI, ApxII, ApxIII, and ApxIV in Pigs with Known and Unknown Actinobacillus pleuropneumoniae Exposure Using a Multiplexing Liquid Array Platform. Clin Vaccine Immunol 2014;21(1):85-95.
- Langenhorst RJ, Lawson S, Kittawornrat A, et al. Development of a fluorescent microsphere immunoassay for detection of antibodies against porcine reproductive and respiratory syndrome virus using oral fluid samples as an alternative to serum-based assays. Clin Vaccine Immunol 2012;19(2):180-9.
- Smits GP, van Gageldonk PG, Schouls LM, et al. Development of a BeadBased Multiplex Immunoassay for Simultaneous Quantitative Detection of IgG Serum Antibodies against Measles, Mumps, Rubella, and Varicella-Zoster Virus. Clin Vaccine Immunol 2012;19(3):396-400.
- Alpay, K. et al. Diet restriction in migraine, based on IgG against foods: a clinical double-blind, randomised, cross-over trial. Cephalalgia : an international journal of headache 30, 829-837, doi:10.1177/0333102410361404 (2010).
- Mitchell, N. et al. Randomised controlled trial of food elimination diet based on IgG antibodies for the prevention of migraine like headaches. Nutrition journal 10, 85, doi:10.1186/1475-2891-10-85 (2011).
- Zar, S., Mincher, L., Benson, M. J. & Kumar, D. Food-specific IgG4 antibody-guided exclusion diet improves symptoms and rectal compliance in irritable bowel syndrome. Scandinavian journal of gastroenterology 40, 800-807, doi:10.1080/00365520510015593 (2005).
- Atkinson, W., Sheldon, T. A., Shaath, N. & Whorwell, P. J. Food elimination based on IgG antibodies in irritable bowel syndrome: a randomised controlled trial. Gut 53, 1459-1464, doi:10.1136/gut.2003.037697 (2004).
- Drisko, J., Bischoff, B., Hall, M. & McCallum, R. Treating irritable bowel syndrome with a food elimination diet followed by food challenge and probiotics. Journal of the American College of Nutrition 25, 514-522 (2006).
- Bentz, S. et al. Clinical relevance of IgG antibodies against food antigens in Crohn’s disease: a double-blind cross-over diet intervention study. Digestion 81, 252-264, doi:10.1159/000264649 (2010).
- Egger, J., Carter, C. M., Soothill, J. F. & Wilson, J. Oligoantigenic diet treatment of children with epilepsy and migraine. The Journal of pediatrics 114, 51-58 (1989).
- Pelsser, L. M. et al. Effects of a restricted elimination diet on the behavior of children with attention-deficit hyperactivity disorder (INCA study): a randomized controlled trial. Lancet 377, 494-503, doi:10.1016/S0140- 6736(10)62227-1 (2011). 8b cookbook
- Veling, M. & Trevino, R. (2002). Food allergies and hypersensitivities. Alexandria, VA: American Academy of Otolaryngology-Head and Neck Surgery Foundation.
- Dixon H, Treatment of delayed food allergy based on specific immunoglobulin G RAST testing relief. Otoloryngol Head Neck Surg 2000;123:48- 54.
- Ciao, G. et al, Effect of gluten free diet on immune response to gliadin in patients with non-celiac gluten sensitivity. BMC Gastroenterology 14, 26 (2014)
- Kemeny DM, et al Sub-class of IgG in allergic disease. I. IgG sub-class antibodies in immediate and non-immediate food allergy. Clin Allergy. 1986; 16:571-81
- Hofman, T. IgE and IgG antibodies in children with food allergy. Rocz Akad Med Bialymst 40, 468-473 (1995).
- Jenmalm, M. C. & Bjorksten, B. Cord blood levels of immunoglobulin G subclass antibodies to food and inhalant allergens in relation to maternal atopy and the development of atopic disease during the first 8 years of life. Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology 30, 34-40 (2000).
- Lucarelli, S. et al. Food allergy in cystic fibrosis. Minerva pediatrica 46, 543-548 (1994).
- van der Woude, F. J. et al. Do food antigens play a role in the pathogenesis of some cases of human glomerulonephritis? Clinical and experimental immunology 51, 587-594 (1983).
- James L.K and Till S.J Potential mechanisms for IgG4 inhibition of immediate hypersensitivity reactions. Current Allergy Asthma Rep. 16:23, 2016 PMID: 26892721
- Caubet J.C. et al. Natural tolerance development in cow’s milk allergic children: IgE and IgG4 epitope binding. European Journal of Allergy and Clinical Immunology, First published: 27 March 2017
Remove this item from your diet or minimize your exposure to it.
Elevated levels of IgG reaction to a certain food does not necessarily mean you have an intolerance, but research shows that by eliminating foods that cause an IgG reaction, you can potentially improve certain food-related symptoms - including gastrointestinal distress, headaches, dry and itchy skin, and fatigue. Please keep in mind that IgG reactivity does not necessarily correlate directly with symptoms, so your results are meant to guide you through the next steps of the process.
Elimination of IgG positive foods may improve symptoms of irritable bowel syndrome, Autism Spectrum Disorders, AD(H)D, cystic fibrosis, rheumatoid arthritis, and epilepsy, according to numerous clinical studies.
IgG food test results are often used to develop food antibody-guided exclusion/ elimination diets. The implementation of such diets has been shown to alleviate symptoms associated with nonceliac gluten sensitivity and food sensitivity-induced atopic conditions, reduce the frequency of migraine headaches, decrease the occurrence of diarrhea, decrease failure-to-thrive among children with cystic fibrosis, reduce symptoms of irritable bowel syndrome, improve rectal compliance, decrease stool frequency in Crohn’s disease, prevent seizures and hyperkinetic behavior in children with epilepsy, and ameliorate kidney function in glomerulonephritis. Food elimination diets also hold promise for the improvement of behaviors associated with attention-deficit hyperactivity disorder.
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