Food Allergy Testing

ELISA Test Results
Click on the image to see it close up.

Just before I started on SCD I did a blood test for food allergies – the ELISA food allergy test. I fully expected to get the results back showing a reaction to gluten, red meat, and certain fruits and vegetables I knew had trouble with. In fact, none of those showed up at all. I was ‘allergic’ to bananas and eggs (especially whites), two foods I was eating the most of and feeling good with. This didn’t sound right to me so I started investigating how the test works.

Food allergy tests (IgG – not anaphylactic-shock reaction testing for IgE) are looking for antibodies to certain food particles. This is how the Celiac blood test works too, it looks for antibodies to gluten. If you haven’t eaten gluten, you will always test negative (one reason why a lot of these tests return a false negative, as some people have already gone gluten-free by the time they test). So if you haven’t eaten a particular food, you won’t test as being ‘allergic’ to it.

If you have leaky gut syndrome, where the intestinal wall becomes permeable allowing food particles to cross over and end up in the blood, you will almost certainly test positive for a number of ‘allergic’ responses. This is because food particles aren’t supposed to be showing up in the blood. A working digestive system will break down food particles so that basic amino acids, fatty acids, minerals, vitamins etc will be absorbed, not larger molecules of food. If larger molecules get through, your body will treat them as foreign and mount an immune system response.

If you have Celiac disease, the damage done to the intestines leaves you with intestinal permiability. This means you need to be aware that other foods are probably causing you problems and will continue to do so until you heal the intestinal tract. I would argue that most people with gastrointestinal symptoms have some degree of leaky gut syndrome. A food allergy test in my opinion is useless except to tell you that you do in fact have leaky gut. It would probably tell you that you’re allergic to everything you’re eating.

Most Naturopaths will tell you to avoid all foods you test high or moderate for, seeing the test as a final result. Do this and take the blood test again in a few months, and I wouldn’t be surprised if your results are different, showing a higher reaction to the new foods you are eating. My naturopath reacted a little differently. She didn’t tell me to cut anything out, but did introduce me to the concept of rotation diet. Foods that I was reacting to at a high level I would not eat every single day, but once every few days. That made sense to me and helped me get a bit more variety in my diet. Especially with meats which at the time I was just eating beef, chicken and pork. I started eating lamb, duck, turkey and various game meats. I also started trying to get seafood once a week. I had a hard time with vegetables and was scared of raw fruit at the time, so I didn’t manage to get much variety there but I did rotate through the ones I was eating.

Here’s the thing though, rotating these foods, having a bigger variety to choose from, avoiding some (eggs) didn’t result in any noticeable difference. Pretty soon I just went back to my usual way of eating, which happened to be eating a lot of the same things for a few weeks until I tried some new recipes and changed it up a bit. Slowly over time my digestive tract healed without me removing individual foods that had shown up on allergy tests.

For me what worked was focusing on three things.

  1. Remove major offenders: these foods are the ones that cause noticeable symptoms, like gluten and most grains for me
  2. Add in as much nutritious healing food as you can: foods containing lots of nutrients, especially if you’re like me and have a hard time eating enough, including shellfish, organ meats, vegetable juices, egg yolks, raw dairy, fruit)
  3. Fine-tune: change it up if it’s not working and take note of how you feel after eating each meal. Change the time of day you eat that type of meal (for example at one point I felt better eating high fat & meat for breakfast, but now I feel better eating lots of fruit for breakfast, meat later in the day). Take notice of how cooked vs raw food affects you, again taking note of the time of day.

I felt after doing the blood test that it was a waste of money. I certainly wouldn’t suggest anyone do it if money is tight. At least it led me to understanding how this all works a bit more, but I still thinking listening to your body is a much better indicator of what to eat.


I have been following the Specific Carbohydrate Diet since January 2008 to recover from Celiac disease. As part of the diet, I don't eat grains, sugar or potatoes and prepare all my meals from scratch.


  1. I have just been through this, I mean I got the test done 4 months back and low and behold I was allergic to ALL the foods I eat regularly, avocados, bananas, almonds, ect..and many veges. I do not eat grains or dairy, so of course it said I was not allergic. The issues I am having is this: All these foods DO cause my symptoms. Generally they are mental, I get very anxious, and heart palpitations and also get gas when I eat the foods I am intolerant to, but I am down to only being about to eat chicken, shrimp, and 4 types of veges. ALL other foods cause me issues. So, I was just wondering if you had any advice, because of course I am developing new issues to the foods I am eating every day. A rotation diet sounds crazy to me right now, with only having 7 foods to eat. I guess I am asking if you think if I incorporated those low “allergy” foods back in our a rotation basis, even though they give me gas and anxiety that I would still heal? I am SO flustered by all this I have been trying to heal for a few years now, but only recently got serious about no grains or refined sugar. I not only have leaky gut but a serious bladder disease that makes it very hard to eat because most foods irritate my bladder as well! So, any advice about these foods is appreciated. I guess I had a theory that said, “How will my body heal if I am constantly attacking it through foods I am eating, wont that create an immune response every time?

  2. Interesting blog post! I agree for the most part. I am a nutritionist and always recommend to my clients that the food allergy test be performed WITH a stool study. The two tests combined can give me a very clear picture as to what is going on in the gut. The stool study can test for good AND bad bacteria levels, parasites, yeast and also how well the GI tract is functioning when it comes to digestion, absorption etc. The stool study helps me know in what direction to go when it comes to healing the digestive tract. The food allergy test helps me know what foods to limit to help the client feel better in the time being. It can be a very slow process, healing the gut.

    The IgA antibody test I have found is more accurate in determining what is directly affecting the gut. IgA antibodies are found in the mucosa of the intestine. Enterolab performs this testing and anyone can have it done (you do not need a physician or nutritionist order). This testing is done through the stool also. For example, I found dairy foods were giving me stomach troubles and when I did my IgG testing, milk did show up under the “mild” category (among many other foods). I went on GAPS diet (for a severe yeast overgrowth found on the stool study) and my gut began to heal. I retested myself and the milk “allergy” was gone…but I continued to react to dairy. I finally did the IgA test through Enterolab for dairy and it was highly reactive….so, my gut was healing and not allowing the milk protein to escape into my blood stream (hence the negative IgG to dairy), but my GI tract was still reacting to dairy through the IgA antibodies contained within the mucosal lining.

    Hope that helps!

  3. Nice post but a bit erroneous. I tested very high to coffee and to pineapple, two foods I’ve not eaten in excess of 35 years. Don’t like them. Don’t like how they make me feel. I expected them not to be a problem because I have not had exposure but there they were, right at the top. This was an IgG panel from Alletess so sometimes you can react without exposure.

  4. @Melissa If you are that sensitive and can tell if you react to foods, then I would say try foods in a rotation diet (even if they were a higher reaction on the test before) and see how you feel. Try and get lots of broth to help heal the gut. If you can handle chicken, try homemade chicken broth first (you don’t have to put veggies in it, just chicken bones is fine). If you react to that you can try other broths, or a gelatin supplement. Stay patient! As @Kelly said it does take time.

    @Karen I think that shows the test is not 100% accurate. Since the test works only by noting reactions between a substance and antibodies in your blood, you should not have a high reaction to something you have not eaten in 35 years. Unfortunately there’s no real consensus on the accuracy or reliability of these tests. Best thing I’ve found in my experience is to note how you react to a food and use that as your guide, not a blood test.

  5. Electrodermal screening might be a better way to check for reactive foods, since it detects sensitivities (not IgG) rather than allergies.
    For those with major/multiple allergy and/or sensitivity issues (including environmental), BioSet or NAET treatments can be a godsend!

    I hope this helps!

  6. Thanks, I cant do broth though because the high mineral count hurts my bladder badly.

    • I found that soup and not broth was of gresy help to a patient of mine with Interstitisl Cystitis. The soup shouldn’t be cooked for long time, 2-21/2 hours maximum. My patient was on the GAPS program.

  7. great post Kat! I’ve been thinking about getting this allergy test for a long time, so you given me alot to think about now. super interesting stuff, and I really appreciate it!

  8. @Melissa Have you tried powdered (purified) gelatin? I too have had bladder issues with broth (and herbal teas) but I never had the same reaction to gelatin in a supplement form.

    @Adam Thankfully it’s not usually an expensive test if you decide you want to do it. I kinda knew it wasn’t a reliable test before doing it, but it was something I wanted to try for myself.

  9. I had that exact blood test done shortly after my IBD diagnosis. I tested HIGH reactivity to ALL grains, ALL dairy, eggs (whites and yolks), ALL nuts (except walnuts which I did NOT like back then), and even a few fruits (banana, blueberries, pineapple) and veggies (squash was one, which I actually didn’t eat very often). Most of the rest had moderate reactions. Meats had NO reaction, but I was a vegetarian! If I had pulled all the “high” results I would have been eating meats, veg, and some fruit. If I pulled out the “moderate” reactions too, well, I would have been eating meat and a handful of veggies. I totally agree these tests more accurately reflect the status of leaky gut, and I hope that time on a diet (such as GAPS or SCD) will heal this issue. Initially, I pulled the high reactivity foods and rotated the rest, but lost too much weight and was miserable trying to batch cook (but keep everything properly separated!) enough food since I was a student and did all of my cooking on the weekends. I survived 3 months like this and I felt no better (in fact, worse) for it.

  10. Has anyone tried the blood type diet? I had/have gut issues which progressed to a lot of joint pain so this is when I started looking up diets and naturopathy. Anyways, I went with a friend to a Nutritionist who suggested the blood type diet format for her weight loss and I did kind of roll my eyes at it, even though I was doing things holistically, and googled it when I got home and gave it another “yeah right”. I went on with my naturopath to get a food sensitivity test done and I am intolerant to grains, milk, legumes, carbs in general so I went back to the blood type diet and there it was – it wasn’t exact – but strikingly similar. I am following it now and I use SCD books, I really like the book Breaking the Vicious Cycle and Dr. Mertola has some interesting stuff. Not to promote anything but I am because it is making a difference for me. I am blood type O btw, so no to low carbs and meats (which came back as 0 reaction on sensitivity test) which makes me sad but I am getting used to it. I have huge differences in bowel activity anyways. Really though, everything is better – teeth, skin, hair, joints, no more UTI infections or irritations) I probably should start rotating my foods as I am favoring things a little too much.

  11. @Amanda While it’s not a bad thing to try a rotation diet, trying one with very limited foods to start with can be really tough. I hope you find SCD or GAPS helps.

    @Janet All the evidence I see for the blood type diet (by following people’s blogs and message boards) is that everyone with blood type O who follows their diet has success. Many people with A, B, AB don’t do well on their diets, and some of them do better following the O diet. So it seems the O blood type diet works well, regardless of what the blood type is 🙂

  12. I appreciate this informative and thoughtful post so much — thank you! My family, as well as many other families that I know of, have been led into a black hole of IgG testing by naturopaths and other well-intentioned providers. As a healthcare provider myself, an IgG response to food is not, in my opinion, a marker of “intolerance” but rather an indication of exposure, as you suggest. I do know of a few families who felt the results were accurate, but I suspect it is only accurate by default. People may have reactions to specific foods in their diet, and by registering exposure, the IgG may incidentally identify some of those foods because it is measuring exposure. Like you say, the real issue here is whether food particles are passing through a damaged gut, and people can begin to work on that through simple food choices and supplements, and without spending hundreds of dollars on equivocal testing.

  13. Hi Kat! I’d like to start SCD diet for my family, especially for my little daughter. The problem for me that she is allergy to white part of eggs. In SCD diet there is a lot of recipes with eggs, what can we do, any suggestion, please?

  14. @Magdalena For baked goods you can try using applesauce or banana instead of eggs, or applesauce + egg yolks. Fruit tends to help hold it together like eggs do. I eat lots of egg yolks raw or cooked, not so much the whites.

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  16. @Kat

    Hi Kat, I’ve been trying to do research on food allergy testing and I’m wondering about your comment ” Since the test works only by noting reactions between a substance and antibodies in your blood, you should not have a high reaction to something you have not eaten in 35 years.” This contradicts what my ND has told me, so I’m wondering where you got this information, or if you could point me in the right direction to find out for myself.

  17. @Laura Hi Laura, there are 2 kinds of allergy testing. Testing for food allergies through blood tests look for antibodies present. Skin patch tests and skin prick tests don’t require that you have eaten the food. What kind of tests did you ND tell you about? I don’t have the links handy now, but I just looked up papers on the ELISA test and how it worked.

  18. Hi Kat, it was the ELISA testing. Which I just had done. I did test high on a couple of foods that I eat frequently (quinoa and almonds), but mostly tested high on foods that I eat once in awhile (crab).

    I was just wondering if you had found info that showed that antibodies could “go away” if you didn’t eat a particular food for “35 years”.

    Thank you for your reply!

  19. @Laura Based on the blood test for Celiac, the food has to be eaten within a few weeks for the test to be accurate. I’ve always heard recommendations of at least 2 weeks of high intake of wheat to test for Celiac. I haven’t found anything that talks about specific timeline for these antibodies to ‘go away’ for either Celiac test or more general food allergy testing.

    Here’s a couple links that explain more about how the tests work. The first link I found particularly interesting in the talk of microorganisms, under What is Really Being Measured in the ELISA/EIA?: “For one, all food (organic and non-organic) is coated with microorganisms.” http://www.tldp.com/issue/174/IgG%20Food%20Allergy.html


    I hope that helps!

  20. what do you thik about testing for Iga anti-bodies in stool samples for food intoerances. are they accurate?

  21. I did the test and I reacted to milk both cow and goat though I haven’t had dairy for months. Also reacted to beef and pork and I have been a vegetarian for 4-5 years nos. Favorite foods almonds, cashews and bananas which I ate weekly if not daily along with eggs and pineapple which I don’t eat very often but had days before the test.

  22. I was looking to know more about food allergy testing. It is good to know that if problems are present, removing major offenders such as gluten and grains might be a helpful idea. Something else to consider would be to seek professional help and do continued research about diet and the food you are consuming.

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  24. This is indeed a must for almost everyone. Food allergy testing should indeed be done early on at least to gain knowledge as to what food are acceptable or at least remotely indigestible for those concerned.

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