Food Sensitivity Testing – What Does It All Mean?

Have you noticed how everyone is suddenly “allergic” to everything? Whether they’re gluten free, or dairy free, or seemingly “everything free” food allergies and sensitivities are on the rise. While some allergies are very obvious, and leave you swelling up like a balloon, other more subtle signs of food reactions are much harder to figure out. Read on to learn about the difference between a food allergy and a sensitivity, and which are useful and a little bit about how to use the information from testing. More on that in a future post.

There are 3 types of food reactions, and the numbering here is not “off” they actually skip #2 and the #3 points are considered the same class.

Type I – allergy, IgE – can be measured in blood or with skin prick: results in hives, anaphylactic shock, etc.

Type III – reaction or sensitivity, IgG antibody measured in the blood: causes inflammation, inflammatory response, leads to leaky gut – IgG is a delayed reaction, can take 6-48 hours to show up.

Type III – reaction or sensitivity, IgA antibody in secretions (mucus, saliva, tears, stool), usually measured in the stool: causes inflammation, leads to leaky gut

Type IV – cell mediated response, measurable in the blood, also leads to leaky gut

Things to know about IgE: these are the only true allergy. At a medical/scientific level an “allergy” must be to protein. IgE allergies are almost always life-long, and cannot be healed with diet changes, gut healing, etc., etc. Skin prick tests are used to challenge for IgE responses. Typically reactions to IgE allergens get stronger and stronger with repeated exposure. These are the tingly mouth, restricted airway, hives type reactions. Peanuts, bee stings, shellfish, latex are common allergens in this class. While these sorts of allergies cannot be “cured” many people do find that their responses improve (decrease) when they address the other food sensitivities that are not true allergies.

Things to know about IgG/IgA: these are not allergies but are sensitivities or reactions. They can be very significant and cause a lot of issues in the body, so classifying them separately from an “allergy” is not to diminish their negative impact. IgG food tests are popular with Dr’s who approach things with a holistic/functional perspective. The LIMITATION of IgG testing is that it’s accuracy can be dependent on recent exposure to the food you are testing. If you haven’t consumed a food in the previous 3 weeks you may be reactive to a food, but not have enough antibodies to it to register on an IgG test. People who are immune suppressed may also be reactive, but not have significantly increased antibodies. IgA antibodies are tested via a stool test. While it is probably possible to get an IgA test for anything, typically I’ve seen them for gliadin, casein, soy, eggs, corn (the big 5). IgA are in secretory fluids, tears, mucus, vaginal fluids, and sweat.

Things to know about cell mediated: the benefit to this test when looking for help with a leaky gut, or other issues like chronic headaches, excess inflammation, neurological distress etc., is that you don’t have to consume it to provoke an accurate test. Instead of measuring the antibody itself, who’s presence depends upon recent exposure to the antigen (food), testing for a cell mediated measures end products of a reaction or sensitivity. There are approximately 100 types of immune cells involved in this (things like cytokines, natural killer cells, lymphocytes etc) and the MRT test is estimated to measure 90 of the 100.

The Dr. who developed and patented ALCAT went on to create the MRT test. Both ALCAT and MRT are forms of cell mediated response testing. ELISA testing is measuring IgG antibodies.

The numbers I have heard is that ALCAT claims 70% reproducibility of their results by 3rd party labs, and MRT claims 90-95% reproducibility. This means that no test is perfect! But these can still be a valuable tool in determining hidden food reactions. The ELISA test does not publish a reproducibility number from a 3rd party lab that I know of. I know some practitioners who find the ELISA testing to be clinically valuable and more who do not.

The commonly accepted “gold standard” testing for food related issues, especially for gluten cross reaction, is Cyrex Labs. However, these tests tend to be in the $2-4,000 range. So if you’re very desperate for help beyond what the other testing can provide or you have the funds at your disposal by all means get testing with Cyrex. They are amazing, but they aren’t within reach for many of us.

Even an imperfect food sensitivity test can be a benefit if you’re working on actual healing, and not just taking foods away. The biggest thing to understand is that if you have leaky gut and simply change the foods you are eating, you will become sensitive to new foods. You should begin a gut healing protocol AT THE SAME TIME as you change your diet! Additionally, if you have pathogenic bacteria overgrowth, chronic candida, parasites etc., this will impede healing the gut. It is very hard to “eat the bugs away”. The most effective approach will be to get tested for all of these factors and to address them all together. However, if you absolutely can not afford the gut testing then you can still benefit from working on the food part alone.

Excellent gut healing type diets are AIP Paleo, GAPS, SCD or SCD/FODmaps, these can all be combined with rotation diets as well. These are all effective, but again, you can’t eat the bugs away. Also I do not think that everyone needs to follow an extreme diet like those are to have success healing your gut. I didn’t and most of my clients don’t. There is no one size fits all.

If nothing else, you can try eliminating the top reactive foods from your diet and see what sort of difference it makes. I suggest doing this for no less than 30 days before evaluating your progress. A great resource for eating this way is the Autoimmune Paleo cookbook by Mickey Trescott. The most common foods that cause reactions / allergies are:

-tree nuts

Comments (4)

    what test to you recommend for someone who does not have leaky guy symptoms but is curious to see if they have a leaky gut?


      I recommend the MRT test as the most accurate to learn about hidden food sensitivities, whether or not they suspect leaky gut issues. But I also don’t think that “curiosity testing” is beneficial unless a person is willing to make diet changes to accommodate the information they learn from the test.


    What does it mean when you say ” 70% reproducibility ” and ” 90-95% reproducibility.” Does it mean the amount of times it is correct? Also if the cell mediate test identify the end result, ie immune cells does it identify what the offending food is or just that you have a leaky gut? Thanks for the clarification.


      Hi Sara,

      Reproducibility is a term used when talking about the accuracy of the test, or the ability to reproduce the same test result with the same sample. Another way of saying it is that the Alcat can have an inaccuracy rate of 30% and the MRT can be 5-10% inaccurate.


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