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The Complete Guide to Food Sensitivity and Intolerance Testing

Medically reviewed by 
The Complete Guide to Food Sensitivity and Intolerance Testing

As digestive disorders are increasing, it’s becoming more and more vital 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 finding a practitioner that can help you.


Food Sensitivities are Not the Same as Food Allergies

It’s very important to understand that food allergies and food sensitivities are two very different diagnoses. The only thing they have in common is the word “food” in their name.

Food Allergies cause an IgE response

An IgE-mediated response is a permanent allergy and causes an immediate histamine reaction within minutes to hours of ingested food. These allergies can be life-threatening.

Food Sensitivities cause an IgG response

Even more common than food allergies, food intolerances are estimated to affect up to 20 percent of the population in industrialized countries.  Food Sensitivities can cause delayed symptoms hours to days after ingested food that can mimic many other diagnoses. IgG-mediated responses are temporary sensitivities that do not activate a histamine response and can usually be remedied with proper nutritional guidance. In many cases, other immunoglobulin antibody responses may also be involved with food sensitivity, including IgA (which is found in the mucus membranes).


Conventional Doctors Rarely Test for Food Sensitivities and Intolerances

Conventional medicine doctors will rarely test for sensitivities because research and testing behind food sensitivities are not as advanced or widely accepted as those for allergies.

Many people believe elimination diets are still the gold standard for figuring out food sensitivities. However, anecdotally patients have benefitted from doing testing.

The Importance of Food Sensitivity Testing

Food sensitivity testing can help pinpoint the exact foods and spices that are affecting our patients’ health. Once the tight junctions have opened up, it is common for the body to react to multiple foods making it hard to narrow down the exact cause.

Who Can Order These Types of Tests

If you are interested in food sensitivity testing, we highly recommend working with a functional medicine practitioner. Not only will they be able to get you the proper testing that you need, but they will be able to interpret results and set you up with a food sensitivity nutrition protocol. The good news about food sensitivities is they usually aren’t permanent, and you usually can reincorporate these foods back in. Your practitioner will help you start adding these foods back into rotation when it's time and then retest to confirm you are no longer making antibodies against these sensitivities.

The Food Sensitivity Test Functional Medicine Practitioners are Ordering

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.

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

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. 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

The information provided is not intended to be a substitute for professional medical advice. Always consult with your doctor or other qualified healthcare provider before taking any dietary supplement or making any changes to your diet or exercise routine.
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