Food Immunology Testing
Many chronic illnesses are linked to unrecognised food sensitivities. IgG food immunology testing is a tool for measuring the degree of inflammatory immune response produced by a wide variety of different foods.
The test measures immunoglobulin G (IgG) antibodies in the blood – antibodies our immune system is generating to fight against various food proteins. If we continue to eat the foods that stimulate strong IgG reactions, we continue to drive an immune response that can manifest as a variety of symptoms.
This test measures our immune response to 96 different foods, to help us understand which foods are driving inflammation and other symptoms. This is called an IgG or type III reaction. It is measured using a test called ‘ELISA', which is used by doctors in assessing immune responses to different proteins, including bacterial proteins, virus particles, and following vaccination. There is growing evidence for the use of this test in relation to food-specific reactions. See the list of links to scientific studies at the bottom of this page to learn more.
The food reactions measured in this test include:
• Dairy proteins such as whey and casein
• Egg proteins from yolk and albumen
• Wheat components such as gluten and gliadins
Common symptoms of IgG-related food sensitivities include:
• IBS – cramps, bloating, diarrhoea, constipation and urgency, and heartburn
• Joint pain
• Ear, nose and throat problems
Our nutritional consultant Debra Ashton has many years experience in tailoring nutritional plans for patients according to their own goals, and counselling patients with practical advice according to their specific immune sensitivities. Click here for more information about Deb's nutritional consultations.
Note: IgG food immunology testing is not an ‘allergy test’ – it tests a different immune pathway compared to skin prick or patch testing. It is of relevance in patients with autoimmune and inflammatory diseases and digestive symptoms, and is less appropriate for patients with anaphylaxis or fast-immune responses to foods.
The mechanism behind IgG food sensitivities
After we eat food, our stomach acid and digestive enzymes act on the food proteins to break them apart into small amino acid ‘building blocks'.
If the lining of our intestines is damaged on a microscopic level, which can occur following infections, alcohol and other things, food proteins can slide through this intestinal barrier before they have been adequately broken down.
The result is that we end up with food proteins in our blood that our immune system identifies them as ‘foreign’ invaders, so that every time we eat these food, we send our ’soldiers’ in to battle.
It is important to emphasise that the reaction we are describing here is not an allergy. Allergies are a fast immune response, regulated by histamine. Symptoms of allergy often come on quickly after exposure to a food trigger.
In contrast, this IgG immune response can take a few days to develop. Cramps, diarrhoea and other symptoms can occur two to three days after exposure to the food, complicating our ability to clearly identify the trigger.
Everyone has mild IgG reactions to various foods. However, if the reaction is very strong, this can reflect a clinically significant result. In these cases, cutting out the foods with strong reactions can result in an improvement of inflammatory and abdominal symptoms over the following weeks.
This is a growing area of research and there is evidence that specific conditions can be improved by avoiding foods where IgG reactions exist. Click on any of the titles in this list to read the scientific studies.
General references on intestinal permeability and immune disease