Exploring food sensitivities and the MRT test - is it legit?

Exploring Food Sensitivities: Is the MRT Test Legit?

Food sensitivities have become a modern-day epidemic, alongside conditions such as leaky gut and dysbiosis (an unhealthy balance of gut microbes).  Regardless of the amount of research that has been done on the immune system at this point in time, the mediator release test (“MRT test”) and food sensitivity testing in general remain controversial among registered dietitians and many other types of healthcare providers in the field of digestion and immunity.

In this article I’m going to nerd out and get clinical, unpacking the validity, reliability, and underlying mechanisms of Oxford Biomedical Laboratory’s patented MRT test, which is designed to uncover and address diet-induced inflammation caused by food sensitivities.

Food sensitivities 101: what exactly are food sensitivities?

Food sensitivities are one of three branches of adverse food reactions.

Unlike food intolerances, which are related to imbalances in the gut (such as lactose intolerance which is caused by a missing enzyme and/or an imbalance of gut microbes), food sensitivities (like allergies) involve the immune system.

(I know – this is where it starts to get confusing!)

However, unlike food allergies, which only involve ONE type of chemical mediator (histamine) and which can occur only within mast cells (a specific type of white blood cell which is located only within the mucous membranes of the body), and which take place only via one pathway called “immunoglobulin E” (IgE), food sensitivity reactions typically involve multiple types of chemical mediators (aside from just histamine), and they can take place within many different types of cells and pathways in the immune system.

Unfortunately for many of us who suffer from chronic illness/inflammation, food sensitivities seem to be the most difficult type of adverse food reaction to identify and treat, because these types of reaction can be delayed, dose-dependent, and person-specific. 

(If this is something that resonates, please know you’re not alone.)

What makes this extra tricky is that while food allergies and food intolerances deliver relatively instant, clear symptoms and reactions, no two people are going to have the same experience when it comes to food sensitivity reactions.

The multitude of ways in which food sensitivities can induce inflammation in the body is broad-spectrum, highly individualized, and multi-dimensional…

What causes food sensitivities?

While there are many different factors playing a role behind-the-scenes in the development of food sensitivities, this type of reaction is most often caused by an unfortunate combination of poor digestion, an overactive stress response, unhealthy gut flora, and a subsequently damaged gut lining (leaky gut syndrome) left unchecked over time. 

(Again, if any of that resonates, just know that you’re NOT alone and that there’s a lot you can do about all of it! You don’t have to live with that stuff.)

How it works: a clinical break-down

  1. Excessive amounts of stress are shown to impair stomach acid production, weaken digestion, and cut off blood flow, nutrient and oxygen supply to the gut, which can compromise the gut lining over time.
  2. Unhealthy “bad” bacteria/yeast/viruses (pathogenic microbes) in the gut can and will damage the gut lining over time if left unchecked.
  3. Unhealthy “bad” microbes in the gut reduce our ability to digest food properly.
  4. Undigested food particles increase the overall burden on our digestive system over time.
  5. When the gut is compromised, undigested food particles begin to “leak” into the bloodstream, and they may or may not get flagged by our immune system as a perceived threat since they are not recognized by the body as food until they are in elemental (fully broken down) form.

Food sensitivities may develop via a process called “mediator release” in which white blood cells release inflammatory chemicals called “mediators” into the blood, to deal with the perceived threat (food particle or chemical), leading to diet-induced inflammation,.

Mediator release: the culprit of diet-induced inflammation caused by food sensitivities

When chemical mediators (such as cytokines and a dozen other types of chemicals) are released into the blood in response to the ingestion of a reactive food or chemical, it causes a cascade of unwanted symptoms which show up as inflammation.

  • For my fellow science nerds who’d like to learn more about how this works, feel free to read more about the science behind the process of mediator release testing here!

Common signs and symptoms of food sensitivities

While this list is not finite or exhaustive, and food sensitivities are usually not a stand-alone cause/trigger of any chronic illness, some of the most commonly seen signs and symptoms of food sensitivities include but are not limited to (in no particular order):

  • Diarrhea-predominant irritable bowel syndrome (IBS)
  • Chronic/cyclic diarrhea
  • Chronic, frequent migraines
  • Fibromyalgia
  • Functional diarrhea
  • Heartburn/reflux
  • Eosinophilic esophagitis
  • Barrett’s esophagus
  • Recurring headaches
  • Celiac disease
  • Cyclic vomiting syndrome
  • Crohn’s disease
  • Colitis
  • Leaky gut syndrome
  • Lymphedema
  • Chronic sinusitis
  • Non-seasonal rhinitis
  • Chronic sinus headaches
  • Chronic otitis media
  • Urticaria / Hives
  • Eczema
  • Psoriasis
  • Psoriatic arthritis
  • Rheumatoid arthritis
  • Autism spectrum disorders (ASD)
  • Attention deficit disorder (ADD) 
  • Hyperactivity with or without ADD
  • Chronic fatigue syndrome
  • Lupus
  • Acne
  • Skin rashes
  • Depression
  • Anxiety
  • Interstitial cystitis
  • Atopic dermatitis
  • Epilepsy
  • Asthma
  • Hormonal imbalance
  • Polycystic ovarian syndrome (PCOS)

Phew! I know it’s a bit overwhelming.

But the good news is you can take infomed action once you’ve cracked your code (figured out the “why”, or the underlying root causes, behind what’s been going on in your body).

Are food sensitivities the same as allergies?

Food sensitivities are completely different from allergies! 

The only common ground food allergies and food sensitivities share is that they’re types of adverse food reactions which both involve the immune system (unlike food intolerances, which are confined to the gut).

  • You can learn more about the key differences between food allergies, food intolerances, and food sensitivities here.

Why are food sensitivities so difficult to identify?

As a reminder, symptoms and reactions caused by food sensitivities can take place up to three or four days after eating a reactive food.  (Yikes!)

It’s also often possible for people to be able to eat certain small thresholds of “reactive” foods in moderation, without noticeably reacting, and for people to develop multiple simultaneous reactions to different types of foods and chemicals.

All of that said, the complex nature of food sensitivities add a thick layer of confusion and overwhelm, to say the least!  

The unique and challenging complexities of food sensitivities make simple, cookie-cutter nutrition interventions like food logging more difficult and less effective at uncovering food sensitivities as diet-induced inflammation triggers.

Enter food sensitivity testing…

Food sensitivity testing: what you need to know

There are a wide range of food sensitivity tests on the market, each which explores a branch or pathway of the immune system.

A few of the most popular types of food sensitivity tests include but are not limited to:

  • Enzyme-linked immunosorbent assay (ELISA)
  • Antigen leukocyte antibody test (ALCAT)
  • Everlywell IgG test
  • Basophil Histamine Release Test (BHRT)
  • Leukocyte Histamine Release Test (LHRT)
  • The patented Mediator Release test (“MRT Test”)

The MRT test is a special type of food sensitivity blood test which detects the outcome of ALL non-allergy-derived immune reactions (or lack thereof) pertaining to 170 different foods and chemicals.

What is the MRT test?

This food sensitivity test is most similar to the ALCAT in that it is an indirect method of measuring “mediator release” (the common end-point of all food sensitivity reactions in the body) by identifying the degree of change in cell volume and the change in ratio of liquid-to-solid volume within white blood cells, before and after exposing them to up to 170 different samples of dietary chemicals, additives, and foods.

The MRT test accounts for the widest range of inflammatory pathways, in that it is measuring the common-ground “end point” of all different diet-induced inflammatory pathways (which is chemical mediator release from white blood cells, into the bloodstream).

The chemical mediators themselves are held responsible for the wide range of unwanted symptoms of inflammation that people are experiencing after eating certain foods/chemicals that they are reacting to.

Are all food sensitivity tests the same?

Each type of food sensitivity test measures something different, and each test has its own set of strengths and weaknesses.

For example, the popular ELISA test measures the color change in lymphocytes after being exposed and incubated with over 400 different types of foods/chemicals.  

  • While that is pretty thorough, the downside of the ELISA test is there are no published studies on reliability or validity, and it overlooks the process of mediator release which is a key component of food sensitivity reactions.

The ALCAT, like the MRT test, measures “end-point” changes in the volume of white blood cells before and after exposure to foods and chemicals, and this test takes the process of mediator release into account.

  • However, while the ALCAT test is relatively accurate (86% accuracy level), it uses older technology, has not been updated since the 1990s, and has a lower degree of split-sample reproducibility compared to the MRT test.

Other types of food sensitivity tests (such as the BHRT and LHRT) assess only a few out of over a dozen different types of mediators which could be playing a role in diet-induced inflammation.

All of that said, I believe the MRT test is currently the most unique, cutting-edge, holistic and multidimensional candidate of all food sensitivity tests on the market!

What makes the MRT test cutting-edge?

While no food sensitivity test is 100% reliable or accurate, the MRT test comes pretty close!

Food sensitivity tests are clinically evaluated in terms of the following factors:

  1. Accuracy (sensitivity and specificity)
  2. Reliability (the ability to repeat the same results multiple times among split samples)

The MRT test has been proven to be the most reliable of all food sensitivity tests in that it has 93.6% split sample reproducibility, and it is 94.5% sensitive compared to multiple other common food sensitivity tests.

  • Four other common food sensitivity tests among nine which were evaluated in a 2004 study were deemed “not reliable” in that very little consistency was found among the results of the four tests measuring IgG, with 79-83% “disagreement” (lack of split sample reproducibility). (2)

If your clinical interest is piqued and you’d like to learn more about what makes the MRT test superior to other types of food sensitivity tests, feel free to read more here!

Addressing the controversy: the MRT test is NOT an allergy test!

To clarify: allergies are a completely separate condition than food sensitivities.  They are not the same thing.  And the MRT test is not an allergy test!

This is why you may see studies and articles/policies undermining the MRT test as a method for assessing  “allergies” – because it is simply not an IgE test/allergy test.

At this point in time, unfortunately nobody on PubMed or in the Academy of Nutrition and Dietetics is willing to admit or acknowledge that the MRT test is not an allergy test, and that IgE-mediated food allergies are in fact a completely different condition than food sensitivities which are not IgE-mediated. (3)

Why this major oversight is still flying under the radar, and why more studies aren’t yet exploring the major role that the process of mediator release plays in diet-induced inflammation, are conversations for another time. 

Please help me to shed light on this major gap and oversight in our healthcare system by sharing this article with someone you know who might benefit from learning more about the process of mediator release, diet-induced inflammation, and the MRT test.

MRT test review: does it work?

Does MRT work? Not necessarily, in that simply running the MRT blood test and then not taking any further action is not going to deliver the results and outcomes you’re likely hoping to achieve.

Any and all types of functional nutrition tests are only as good as (1) the ability of your practitioner to interpret your test results, (2) the ability of your practioner to provide the right treatment plan and protocols, and (3) your readiness to implement what is recommended.

(Bottom line: throwing money at your problems is not enough to make them go away!) 😉

It’s important to keep in mind that no food sensitivity test is never 100% accurate, and our food sensitivites can change and evolve over time depending on what we eat. So if you’re working with a very outdated MRT test (more than a year old), you’re probably due for an update!

The MRT test is also not for everyone, especially for those who don’t meet clinical criteria, and/or those who struggle with disordered eating or an unhealthy relationship with food/self-care.

On the other hand, if you are a great candidate for MRT, and you’re highly motivated to take action and implement what you learn based on your results, this highly specialized food sensitivity test can serve as a wonderful informative tool in that it can help you to crack your code (from a food sensitivity standpoint) and identify some of your body’s best foods! 

From there, once you have access to this information revealed through the MRT test, it’s important to then implement what you learn and make the necessary changes that will allow your body to heal.

MRT and LEAP: the dynamic duo!

Working with a certified Lifestyle Eating & Performance (LEAP) therapist is considered the “gold standard” and highly recommended, when it comes to interpreting your MRT test results which are not going to be “cookie-cutter” or easy to decipher.  

Since the MRT test doesn’t test for food allergies or food intolerances, it’s important to also address and rule out those other types of adverse food reactions (with help from your certified LEAP therapist) as a holistic component of your medical nutrition therapy treatment plan.

From there, your LEAP therapist will help you to get started on a custom plan (designed just for you) which will give both your gut and immune system some space to finally breathe, so you can heal and get the results you want!

When properly executed and paired together in tandem, the MRT and LEAP diet protocol can and will do wonders for those who meet the criteria for these protocols and take informed action based on what is recommended by their LEAP therapist.

Recent MRT + LEAP client testimonial:

“I’ve had migraines for 50 years, GI symptoms for 30 years and chronic eczema for a decade. Despite a career in medical research, giving me access to some of the best physicians, newest drugs, and latest research, I’ve gone a lifetime thinking this was just my miserable normal.

Then, I read a brief article by Whole-istic Living that piqued my interest and, despite low expectations and hard-earned skepticism. I decided to give Jenna a call.

Jenna patiently allowed me to question every suggestion, to research all the relevant academic publications, and to move slowly as she ordered a series of tests to identify my food sensitivities and thoroughly access my nutritional needs. Then, she gave me weekly encouragement as we drastically changed my diet and lifestyle.

Now, after just three short months, Jenna has literally changed my life! My headaches are becoming rare, the rash is mostly gone, and most-importantly I feel great. I’m amazed that a relatively simple change in diet has accomplished all this. I only wish that I had met Jenna a lifetime ago.” – S.M.

MRT test: final thoughts and next steps

In this very complex field, it would be ideal to run more clinical studies that can reinforce and reconfirm the validity and reliability of the MRT test and LEAP diet program for assessing and treating diet-induced inflammation caused by mediator release and subsequent food sensitivities.

In the meantime, while the MRT test and LEAP diet protocol continue to remain controversial among registered dietitians and other healthcare practitioners, I will continue to offer MRT and LEAP in my practice as long as they continue to serve my clients who struggle with food sensitivities. The proof is in the pudding!

That said, if you’d like to learn more about mediator release testing and LEAP services, you can check out details here on the step-by-step process of getting started, and how it works.

Feel free to reach out if you believe you could be a good candidate for the MRT test which is included in my 1:1 functional nutrition program!


  2. Herman, Patricia M, and Lisa M Drost. “Evaluating the clinical relevance of food sensitivity tests: a single subject experiment.” Alternative medicine review : a journal of clinical therapeutic vol. 9,2 (2004): 198-207.
  3. Collins, Sherry C. “ “Practice Paper of the Academy of Nutrition and Dietetics: Role of the Registered Dietitian Nutritionist in the Diagnosis and Management of Food Allergies.” Academy of Nutrition and Dietetics vol. 116,10 (2016): 1621-1631.

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