The Complete Guide to Food Sensitivity and Intolerance Testing

Tara Viswanathan
The Complete Guide to Food Sensitivity and Intolerance Testing

Worried you might have a food sensitivity or intolerance? Feeling bloated, gassy, exhausted, or just plain uncomfortable after you eat, and don’t know where to start? You’ve come to the right place.

As digestive disorders are increasing, it’s becoming more and more important to become aware of any food sensitivities and intolerances you’re dealing with that might be contributing to or causing your symptoms.

Here’s everything you need to know about navigating the food sensitivity world - from the science behind it all to validity of at-home test kits to the types of elimination diets and more.

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Food sensitivities or intolerances are not the same as food allergies.

Many people use the terms allergy, intolerance, and sensitivity interchangeably - however they’re each different. Food intolerances or sensitivities are not the same as food allergies.

Conventional doctors rarely test for sensitivities and intolerances.

Food allergy testing will not necessarily show you food sensitivities or intolerances and vice versa. Research and testing behind food sensitivities and intolerances are not as advanced or widely accepted as those for allergies. Conventional medicine doctors will rarely test for sensitivities and intolerances because there are limited studies done on the accuracy of these tests. Many people believe elimination diets are still the gold standard for figuring out food sensitivities. However, anecdotally patients have benefitted from doing testing.

In this article we lay out the options for food sensitivity and intolerance testing. For food allergies, check out our guide here.

You can come up negative for food allergies but positive for food sensitivities and intolerances - for the same food.

“In a true food allergy, a person’s immune system produces immunoglobulin E (IgE) antibodies in response to her consumption of a particular food. These IgE antibodies initiate a cascade of events that can affect the skin (hives), the respiratory tract (wheezing), and/or the GI tract (vomiting).

Even more common than food allergies, food intolerances are estimated to affect up to 20 percent of the population in industrialized countries.  Food intolerances are not IgE mediated and are thought to be caused by specific enzyme deficiencies, impaired food absorption, and other GI issues. In many cases, other immunoglobulin antibody responses may also be involved (IgA and IgG).”

- Chris Kresser, Founder, California Institute for Functional Medicine

Food allergy tests will look to see if your immune system is reacting to a particular food by measuring IgE antibodies, and these tests are considered standard across conventional medicine. Food sensitivities or intolerances only sometimes involves the immune system, are usually tested through IgG or IgA antibodies, and usually aren’t immediately life threatening, though they can become very serious if unmanaged.

What are functional medicine doctors  saying, and what tests do they order?

Suspected food sensitivities are a common reason for seeking functional or integrative doctors out. We decided to look at what some of the most well-known functional medicine doctors believe about food sensitivity testing, and what tests they order for their patients.

Amy Myers, MD (Aug 2018)

Functional Medicine M.D., New York Times Bestselling author

  • Her philosophy: “Your body knows better than any test”.
  • Food sensitivity tests are the 2nd most commonly ordered test in her practice.
  • Number one place to start is the Myers Way, an elimination diet for the top 12 foods.
“If my patients are really data driven and want a test done, I order the Immunolabs food sensitivity test, because it’s the most ‘reputable and repeatable’.”

Recommended Tests: Immunolabs Food Sensitivity Test

Dr Chris Kresser (updated July 2019)

M.S. L.Ac., Founder of California Center for Functional Medicine

“I do believe that IgG and IgA testing at least has the potential for meeting the criteria I mentioned (the methodology must be plausible, it should be independently verified, and the results should be consistent and reproducible) for establishing a reliable test. However, whether this criteria is actually met depends a lot on the specific lab and the procedures that they use.”

Recommended Tests: Cyrex Array 3, 4 and 10

When does he order each?

Cyrex Array 3: Gluten / Wheat Sensitivity Panel

“So because I’m still not 100% certain about these tests, here’s how we tend to use them in my practice. With the Cyrex Array 3, which is their gluten/wheat sensitivity panel, definitely the most advanced test of that kind available, if a patient is already 100% gluten free and doesn’t have any interest in eating gluten, I don’t actually think there’s any need to run that test, and it probably won’t be useful anyway because if they’re not eating gluten, they’re not going to be producing antibodies to it.  However, if a patient is still eating some gluten or they would like to be able to occasionally eat gluten if they go out to a restaurant or something like that as part of their 80/20 rule, we will run Cyrex 3 and use it as a means of determining reactivity.  If they have positive markers on that test, given what we know about gluten intolerance and the links between it and many other clinical problems, diseases and health conditions, I will usually advise strict removal of gluten for life.  Now, having said that, there is some research that does suggest it may be possible to restore oral tolerance to gluten, and I’ll discuss this in a future episode, so in some cases, it may be worth retesting after you’ve addressed those issues to see if there’s still antibody production happening.”

Cyrex 4: Gluten-Associated Cross-Reactive Foods Sensitivity

“For patients that are positive to Cyrex 3, we’ll often run Cyrex 4 to see if they have intolerance of other food proteins, and according to Cyrex’s internal research and some peer-reviewed research, people who either have celiac or non-celiac gluten intolerance are far, far more likely to react to dairy proteins and proteins in some of these other foods like coffee and alternative grains and yeast, etc.  So we will do Array 4 to see if they have intolerance of these other proteins, but in this case, we will often do an elimination provocation protocol if they want to try bringing some of these foods back in to see if they react after we have addressed their gut health and some other underlying issues that can lead to food intolerances.  So we don’t necessarily believe that the positive results that come up on Cyrex Array 4 mean that the patient is going to have to avoid those foods for the rest of their life, but we will address those underlying problems and then have the patient retest in the future.”

Cyrex Array 10: Multiple Food Immune Reactivity Screen

“Now, Cyrex Array 10 is their newest test, and this looks at intolerances to many other foods, not just wheat and gluten on Cyrex Array 3 and then the cross-reactive proteins on Cyrex Array 4.  Array 10 looks at all kinds of other foods, fruits and vegetables and meats and things that people typically eat.  And we usually only order this if we’ve addressed gut issues and other underlying issues but the patient is still having problems that seem to be related to food.  I think that it’s better to treat the underlying causes of food intolerances whenever possible than it is to tell someone to remove 25 to 50 foods from their diet forever.  But having said that, if the patient is struggling to deal with some of these things and just wants to feel better, there’s no reason not to run the Cyrex Array 10, have the patient remove some of those foods that are positive from their diet and start feeling better and reduce the immune reactivity while you’re addressing the underlying problems, which hopefully down the line will enable them to eat some or most or even all of the foods that they’re showing reactivity to in the future, because the reactivity is typically caused by a breach of the gut barrier or an infection or bacterial overgrowth in the small intestine or dysbiosis or any of the things that compromise gut health and oral tolerance in general, and if that’s the case, then it makes sense that addressing those things could lead to resolution of those intolerances in the future.”

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Andrew Weil (2008)

M.D. Harvard Medical School, Founder & Director of the Arizona Center for Integrative Medicine at the University of Arizona

“I discussed the issue of food sensitivity testing with Randy Horwitz, M.D., Ph.D., medical director of the Arizona Center for Integrative Medicine at the University of Arizona, who specializes in immunology. “

We agree that the only reliable approach to determining food intolerances or sensitivities is to use avoidance and provocative food intolerance testing – in other words, an elimination diet followed by a “challenge” to see whether a suspect food really does set off a reaction.

Recommended Tests: None, Elimination Diet instead

Mark Hyman (2012)

M.D., Founder of the Cleveland Clinic Center for Functional Medicine, New York Times best-selling author

(P.S. Dr. Hyman uses the term “low grade food allergies” and “food allergens” instead of “food sensitivities”.)

Three Ways to Identify Food Allergies

Blood testing for IgG food allergens (Immunolabs and other labs) can help you to identify hidden food allergies. While these tests do have limitations and need to be interpreted in the context of the rest of your health, they can be useful guides to what’s bothering YOU in particular. When considering blood tests for allergens, it’s always a good idea to work with a doctor or nutritionist trained in dealing with food allergies.

Alternatively, Dr. Mark Hyman believes you can:

  • Go dairy- and gluten-free for 6 weeks. Dairy and gluten are the most common triggers of food allergies. For patients who have trouble losing weight, I often recommend a short elimination, as part of the The Blood Sugar Solution. Both dairy (milk, cheese, butter, and yogurt) and gluten (most often found in wheat, barley, rye, oats, spelt, triticale, and kamut) are linked to insulin resistance and, therefore, weight gain. Temporarily cutting them out of the diet, allows the inflamed gut to heal. This one move may be the single most important thing most you can do to lose weight.
  • Avoid the top food allergens. If you don’t feel a sense of relief from nixing dairy and gluten, you may need to take the elimination diet one step further by cutting out the top food allergens: gluten, dairy, corn, eggs, soy, nuts, nightshades (tomatoes, bell peppers, potatoes, and eggplant), citrus, and yeast (baker’s, brewer’s yeast, and fermented products like vinegar). Try this for a full six weeks. That is enough time to feel better and notice a change. When you reintroduce a top food allergen, eat it at least 2-3 times a day for 3 days to see if you notice a reaction. If you do, note the food and eliminate it for 90 days.”

Recommended Tests: Immunolabs, testing dairy & gluten elimination

Dr. Joel Adams

Director of The Center for Functional Medicine in Stamford, CT and the Medical Director of KBMO Diagnostics,  the Director of Curriculum development of the Functional Medicine Coaching Academy, and a member of the senior faculty of The Institute for Functional Medicine

“In clinical practice, I always had a hard time keeping patients motivated to stay on the elimination diet. The elimination diet for me in practice was very, very challenging and maybe, and I hate to say this on the air, but maybe if I was lucky I got 50% compliance. So I’ve always been looking for the right food sensitivity test because why have patients eliminate common foods that people are allergic to or sensitive to when they themselves may not be sensitive to them.

So take soy, for example, maybe a particular patient isn’t sensitive to soy so to make them eliminate all of that food in the elimination diet just never made sense to me. So I just happened to come across this particular test and I saw that it was called the food inflammation test, or the FIT test, and I happened to run into the CEO at a conference and we just struck up a conversation and I said, this really intrigues me because I understand the importance of inflammation as one of the main upstream causes of everything that’s wrong with my patients, and tell me why you call this the food inflammation test. He explained how this test is the only one out there that actually looks for foods that trigger inflammation, not just foods that trigger some sort of immune response. That really resonated with me because I’ve always been an educator at IFM that has looked for the right food sensitivity test and I will tell you that

“To me, food sensitivity testing has been essentially the Wild West, that it’s been very, very hard to identify a good test that was reproducible and correlated with symptoms and didn’t always come up with a hundred foods that people had to avoid.”

Recommended Tests: KMBO FIT Test

Want to get a food sensitivity test done, but not ready to see a functional medicine doctor? Good news, you can order tests yourself though direct-to-consumer lab testing.

While almost any doctor can order food sensitivity testing for you - now you can order that same testing yourself without scheduling an appointment, visiting your doctor, and having them order the testing for you. With direct-to-consumer lab testing, in most states you can now order these exact labs yourselves - in just a few clicks online! You can save hours of your time and the extra cost of the doctor’s appointment. In addition, food sensitivity testing & reports are relatively simple to read on your own, and you can always get a doctor to look them over afterwards.

However, an innocent google search can quickly lead you down a rabbit hole of hundreds of websites with confusing language, conflicting price points, and sketchy marketing. That’s why we took the time to do the research for you. (P.S. We are not connected to any of these companies and do not receive any kick backs from them - this is just our thoughts on how we’d approach testing for ourselves!)

woman on laptop in bed

Where can I order my own IGG Blood Test?

We researched the best places to order your own food allergy tests. Here’s the breakdown of the direct-to-consumer testing for IgG blood tests, no doctor needed.

EverlyWell- $159, 96 foods

LifeExtension- $198, 95 foods

BodyHealth IQ- $149, 96 foods

Viome- $89, 40 foods

Wellnicity- $189- 90 foods

Be careful- make sure the test is for IgG if looking for food sensitivities. IgE tests are for food allergies.

Some use these terms interchangeably,

I’m in, tell me more! (FAQ)

Can I use insurance?

No, IgG tests aren’t covered by insurance, whether you get them through a functional medicine doctor or not. However, the benefit of ordering it yourself is saving time and convenience.

Where do I get my blood drawn?

Most of these tests are at home test kits - where you’ll do a finger prick with a few drops of blood on a test strip that you’ll mail back to the company.

How do these companies work?

You generally order the test online, they mail you a test kit that you’ll complete at home and mail back. Results usually take about 2 weeks to show up and are reviewed by a physician before they get to you. You usually have the opportunity to speak with a physician as well, through most of these companies.

Are there other direct to consumer lab test companies?

Consumer Reports has done a great overview on different DTC lab companies. However, not all of them do comprehensive functional medicine lab testing. That’s why we created this guide for you!

Note: Direct Testing is not allowed in certain states. (NY, NJ, MD, RI and more) Check to see if your state is allowed.


Tara Viswanathan
Founder & CEO, Rupa Health. Certified Nutrition Counselor. Stanford University
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