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Food Allergy & Sensitivity tests (IgG & IgE): Worth It?

Many people find themselves in the medical hurricane of trying to find answers. From digestive problems, to autism, and everything in between, many eventually get food allergy testing in the form of an IgG and/or IgE blood panel test looking for answers. To no surprise, they test 'sensitive', 'intolerant', or 'allergic' to numerous foods. As a result, they are told to avoid these foods and carry on with their lives. This does not solve the underlying problem. What often happens is the symptoms continue and the number of food intolerances continue to increase. They are left in a one sided battle of searching for empty answers and still feeling hopeless.

If blood work is not covered by your insurance, blood tests for food sensitivities can be expensive. Are they worth the cost and time? My answer is: NO. Let's talk more about why.

IgG is an immune response. It is the most common antibody produced by the human body. states, "...In studies on lessening allergic reactions to things like milk or peanuts, researchers have found that IgG levels go up as the severity of an allergic reaction goes down. It’s thought that we produce the most IgG antibodies to foods that we eat regularly—“like getting a constant booster shot,” says allergist Stuart Carr. That’s why common foods, like dairy, wheat and egg, will often show up positive on an IgG test." It is evident that IgG test results may simply indicate that a specific food is present in the diet.

The IgE blood test is said to be the test more specific to a true allergy. A food allergy occurs when the body’s immune system sees a certain food as harmful and reacts by causing allergic symptoms, and in response it is said the body's immune system will make antibodies called immunoglobulin E (IgE). There are also discrepancies about the usefulness of IgE blood tests and not being very accurate. "One review of 125 kids found that 80% to 100% of the foods that IgE tests flagged could be safely reintroduced into their diets. Another study looked at over 700 oral food challenges – where a person eats a small amount of a suspected allergen under medical supervision—and found that only 19% of patients reacted." When looking at studies done on IgE testing, it is quite clear, that in many cases these results are not an accurate representation of a true food allergy.

These blood tests do not define a food intolerance nor a diagnosis.

The Canadian Society of Allergy and Clinical Immunology released in 2012, that there is no research supporting using these tests (IgG & IgE) to diagnose or predict adverse reactions to food. Statements have also been made affirming this by the The American Academy of Allergy Asthma and Immunology and the European Academy of Allergy and Clinical Immunology.

The problem with IgG and other food sensitivity tests, is that they often lead to false answers of foods one is intolerant or sensitive too. This means they are not only spending their time and money having these tests done, but they may be eliminating foods unnecessarily. Eliminating these foods will not address the root cause of the problem.

What is the root cause?

The root cause of the issue is a leaky gut. There are different culprits that damage the intestinal wall that create little holes in those tight junctions. This allows undigested foods to leak out into the blood stream also known as the 'leaky gut'. This results in various symptoms that can affect any part of the body. Many report digestive symptoms. Other symptoms of a leaky gut can show in the form of eczema, skin issues, headaches, brain fog, autoimmune disorders, hormonal issues, anxiety, depression, OCD, autism, ADD/ADHD, the list goes on. Dr. Natasha Campbell-McBride says it is not unusual for a GAPS patient to test intolerant to just about everything that person eats!

What should we do instead?

The best standard test when testing for food sensitivities and intolerances is an elimination diet like the GAPS protocol and listening to the body as we reintroduce foods.

Our bodies have an amazing ability to heal when given the proper tools and nourishment. As we heal and seal the holes in the intestinal lining, the body starts to heal and repair, and undigested foods no longer "leak" out into the bloodstream. This result allows the body to digest and absorb foods & the nutrients from the foods you are eating. But, the biggest win here, is we see food allergies, intolerances, and sensitivities heal. We are able to slowly reintroduce foods and people no longer 'react' or have 'symptoms' related to that food.

It is very important when doing the GAPS protocol to heal food sensitivities, that we must follow the protocol. We need to avoid foods not allowed on the GAPS diet as these foods can cause inflammation and irritation to an already damaged gut wall, which is what we do not want. We want to give the gut time to rest and heal. The moral of the story is: Don't keep scratching an open wound or it wont have time to heal!


Have questions about whether the GAPS diet is right for you? Have questions about whether you should do the Full GAPS diet or Introduction diet? Wonder if the protocol can heal your food intolerances like it has healed mine? Please reach out, I would love to chat with you! You can email me at and we can schedule a consultation to go over your individualized questions & needs!


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