The Myth of IgG Food Panel Testing
IgGEs Food Panel Test Very common for patients to feel they have food allergies or food intolerances/sensitivities. These terms or labels are often used interchangeably. However, it is important to understand that allergies are very different from intolerances or sensitivities. There are excellent materials on this website to help you distinguish between the two. With a food allergy, the body mounts an immune response to the food, and this can be dangerous. With an intolerance or sensitivity, the body may simply not be processing or digesting food properly and this is not really dangerous (although it can obviously be uncomfortable).
More classic food intolerances (such as lactose intolerance) cause patients to experience bloating, fullness, stomach pain, gas, and/or diarrhoea when they eat too much food. This is because the body is not digesting food properly, leading to a buildup of air and gases in the stomach and intestines. Other patients experience headaches, fatigue, “brain fog” or stomach pain with various foods or additives/preservatives. Oftentimes, patients feel that multiple foods may be causing these symptoms and are hoping to find a single test that will tell them exactly which foods to avoid so they can simply feel better.
Unfortunately, there is no single test that can give you this answer. One test that claims to be able to diagnose food sensitivities and is commonly available in the food IgG test. This test, offered by several companies, reports IgG levels for multiple foods (typically 90 to 100 foods with a single panel test) and claims that eliminating foods with high IgG levels can lead to improvement in multiple symptoms. Some websites even report that diets using this test can help with symptoms of irritable bowel syndrome, autism, cystic fibrosis, rheumatoid arthritis, and epilepsy.
It is important to understand that this test has never been scientifically proven to do what it claims to do. The scientific studies provided to support the use of this test are often out of date, in unaccredited journals, and many have not even used the IgG test in question. The presence of IgG is probably a normal response of the immune system to food exposure. In fact, higher levels of IgG4 to foods may simply be associated with tolerance to those foods.