Special Interests
IgG Food Intolerances
There is growing evidence that food-specific IgG antibodies can be associated with many chronic health conditions. Our body’s defense system can be expected to produce some levels of IgG antibodies to specific foods, and to combine proteins with the foods to form complex molecules, cross the intestinal wall, and enter the bloodstream. When the immune system is working well, these complexes are destroyed by macrophages. However, if there is an overload or a flawed immune system, these complex molecules can circulate in the bloodstream, deposit, and accumulate in various tissues, leading to inflammation and a myriad of chronic diseases.
The diseases and conditions that have been associated with raised levels of food IgG antibodies:
- Irritable bowel syndrome
- Inflammatory conditions such as arthritis
- Migraines and headaches
- Respiratory diseases such as asthma
- Gastrointestinal: Bloating, gas, constipation, diarrhea
- Tiredness, not feeling well
- Rashes, eczema
- Obesity
It can be challenging to identify the food(s) that are linked to the symptoms. IgG food sensitivities are typically a delayed reaction which means the symptoms may not appear for days, making it hard to identify them. Elimination diets are based on guesswork and can take a lot longer to determine which foods are causing the issue.
IgG
Food Intolerance Test
IgG Food Intolerance Test is a valuable tool to take out the guesswork, and help patients achieve a better quality of life. The test uses microarray-based ELISA technology that measures IgG antibody levels in over 200 different foods. The testing panel includes foods commonly known to cause food intolerances, such as dairy, eggs, wheat, soybean, and nuts. The test also includes foods that may lead to the development of sensitivities; but, may not be suspected initially, such as cola, nut, rice, sunflower, and sesame seeds.
Strict control processes are in place to ensure the quality of the foods used for testing, and that there is no contamination. The food antigens are applied to a nitrocellulose pad for testing. Reagents are added through a series of steps that develop a fluorescent colour which is proportionate to the number of IgG antibodies present. Each food is tested in duplicate (meaning twice), and each patient test is run with known standards and controls, providing confidence in the accuracy of the results.
The report provides quantitative results that can be used to help design an elimination diet. Eliminate the foods with the highest marks and start re-introducing the foods with the lower results first.
Cross-Reactivity
It is essential to understand the role that cross-reactivity plays in the interpretation of results. Cross-reactivity occurs when the immune system reacts to a similar or identical protein of other foods or pollens. These are known as pan allergens. If there is a 70% similarity, cross-reactivity can lead to an increased result, even if the patient has not consumed the specific food. These reactions should not be considered a false positive because those results may reflect a pattern of clinical sensitivities, including the possibility of a pollen sensitivity.
Current publications focus on IgE antibodies; however, cross-reactivities can overlap between IgE and IgG antibodies, given their relationship. For example, it has been shown that birch pollen can have cross-reactivity with peanut, hazelnut, potato, soy, almonds, and foods that contain similar storage proteins, such as lentils, peas, and walnuts.
IgG
Allergy or Food Intolerance?
It is essential to understand the differences between an allergy and an intolerance.
Food allergy is an immune reaction that results in the production of IgE antibodies. The responses are usually immediate, and symptoms can range from rashes, swelling, violent sickness, difficulty breathing and anaphylactic shock.
Food intolerances that are immune-related result in the production of IgG antibodies, and symptoms are usually not as severe and may not appear for several days.
If you have a food allergy, it is essential to continue avoiding that food, regardless of the test results obtained in the Food IgG Intolerance Test.
This advice also applies if you have been diagnosed with Celiac disease or any other food-related conditions such as lactose intolerance or gluten intolerance.