Food Sensitivity Testing: What’s the Best One?

by | Feb 8, 2023

Are there foods (even healthy ones) you suspect might be causing your unwanted symptoms?

Do you start the day feeling well, but by 4pm, feel bloated and have no energy?

Are you unable to sleep well at night due to achy joints or sinus congestion?

You might have food sensitivities.

The most common symptoms of food sensitivities are:

  • Low energy
  • Chronic fatigue
  • Aching joints
  • Sinus congestion
  • Runny nose
  • Bloating
  • Diarrhea
  • Pain in abdominal area
  • Headaches
  • Brain fog
  • Skin rashes
  • Water retention
  • Poor sleep

It’s important to work with your doctor to rule out any serious conditions that could be causing your symptoms.

But if you’ve done that, and are still stuck not finding any relief – then food sensitivity testing can shed some light and possibly help you feel better.

Let’s back up for a second though.

There are 3 main ways your body can react to foods – and they’re each very different from each other.

Three Types of Reactions to Foods:

1. Food allergies

These type of food reactions involve the immune system. When you eat a food you’re allergic to, your mast cells release histamines and other inflammatory mediators. This happens quickly and creates difficulty with breathing, throat swelling, itching, and usually hives. This type of reaction is caused by IgE antibodies.

It can be helpful to see an allergist to get food allergy testing done, since a food sensitivity test will not tell you foods to which you’re allergic.

2. Food intolerances

This type of food reaction does not involve the immune system. Rather, food intolerances are usually due to your body lacking digestive enzymes to break down a food for proper digestion. These reactions can cause bloating and diarrhea.

3. Food sensitivities

With food sensitivities, these involve the immune system, like with food allergies, but sensitivities are not caused by IgE antibodies. When you eat a food you are sensitive to, your body releases inflammatory mediators from your white blood cells.

Then you experience symptoms. This can be directly from antibodies or your cells.

This causes a delayed response in your body and can create symptoms anywhere blood flows.

There are blood tests to help you determine which foods are causing your body to release inflammatory mediators due to food sensitivities.

Antibodies and Food Sensitivities (Type III)

Food sensitivities can be caused by antibodies like IgA, IgG, and IgM. Your immune system makes these antibodies to fight off bacteria, viruses, and other invaders that create illnesses.

IgG antibodies are found in your blood and tissues. IgM is mostly found in your blood. IgA is found in fluid that your mucous membranes make, such as saliva, tears, and nasal secretions.

These non-IgE antibodies can create a delayed onset of symptoms (up to 3 days after eating a food) and can affect you anywhere in the body – from head to toes.

Non-Antibody Reactions and Food Sensitivities (Type IV)

With food sensitivities, your white blood cells can also be triggered to release mediators without involving antibodies (aka: cell mediated).

Most food sensitivity tests do not test this type of reaction – they usually only test one or two antibody reactions.

You Need to Test ALL Pathways for a Complete Picture of Food Sensitivities

When trying to determine if you have food sensitivities, it’s important to assess all the pathways your body can react to a food. If you miss a way that your body reacts to food that causes symptoms, then you’re not getting a complete picture of how a food affects your body.

A good food sensitivity test measures all possible pathways that cause symptoms. This test will measure both antibody-mediated reactions and cell-mediated reactions – both type III and type IV.

Without Accurate Testing, You’re Guessing!

It can be difficult to determine which foods cause your symptoms when you’re dealing with food sensitivities. This is because sensitivities and symptoms can show up days after eating a food.

You may not realize something you ate on a Sunday is causing your fatigue, bloating, and aching joints that start the Tuesday after.

Keeping a food journal can even leave you guessing as to what is causing your symptoms since food sensitivities can take days to show up.

The more symptoms you have from the list above, the better candidate you are for food sensitivity testing.

But remember – you want a test that tests all possible pathways – not just one or two.

The current food sensitivity test landscape is full of options.

So which test is best?

I mean – it’s your money – you want to spend it on the most comprehensive food sensitivity test that will help you.

The Mediator Release Test (MRT)

The gold standard for food sensitivity tests is, by far, the Mediator Release Test (MRT). This includes the personalized eating plan you receive once tested, called the LEAP protocol (Lifestyle, Eating and Performance).

Working with a trained dietitian for MRT is the best way to get the most out of your test since we are certified to help you fit the protocol into your current lifestyle.

This is Temporary!

It’s important to remember – food sensitivity testing results should NEVER be interpreted as a list of foods you should avoid FOREVER.

The goal is to stop eating the foods you’re sensitive to for a period of time. This allows your immune system to “forget” it’s sensitive to certain foods, as your body’s cells are constantly turning over and creating new cells.

Then you will slowly reintroduce foods you were sensitive to at the time of testing, and monitor your symptoms while you do.

The goal is to eat as varied a diet as possible – while still not experiencing symptoms.

When you get tested using MRT, you’ll know exactly what foods you should temporarily avoid.

This is better than guessing which foods to avoid while you follow a typical elimination diet that does not involve bloodwork.

How MRT Works

After you purchase an MRT kit, you test kit gets mailed to your home with complete instructions on what to do next.

Then, after a simple blood draw, you’ll usually receive your test results within a week of the lab receiving your overnighted test kit for analysis.

Then, you should work with a certified MRT dietitian who can help you feel better by addressing the food sensitivities that are contributing to your symptoms.

We can help you come up with a plan that fits into your busy lifestyle.

The lab that performs the MRT testing is Oxford Biomedical in Florida, USA.

Once they receive your completed test kit, Oxford exposes your blood to 176 foods and food chemicals.

Then, they use a machine that monitors how much your white blood cells shrink by releasing pro-inflammatory mediators into your blood when it is exposed to these foods and chemicals.

Oxford is measuring subtle changes in your lymphocytes, neutrophils, monocytes and eosinophils. They are measuring changes in the solid-to-liquid ratio of your blood.

The more inflammatory mediators are released, the more of a sensitivity you have to that food or chemical.

Some inflammatory mediator release is a normal function of our immune system. When your body senses a release, your body will usually also release anti-inflammatory mediators to neutralize any inflammation.

However, when a lot of these pro-inflammatory mediators get released, your body has a larger reaction, there is more inflammation and you experience unwanted symptoms.

What Does MRT Food Sensitivity Testing Show Us?

Oxford will test 176 foods and food chemicals like broccoli, yogurt, lettuce, eggs, garlic and MSG. Other food chemicals they test include caffeine, fructose, and aspartame.

The length of the green, yellow or red bar on your test results indicate the amount of mediators your white blood cells released when exposed to that food or food chemical.

Then we’re able to come up with your customized, temporary eating plan to help you start feeling better.

To Decrease Inflammation, Know the Culprit

When you think about it, eating food is something we have to do each day – multiple times a day.

Since food can create issues if we eat something that causes our body to have a reaction and be inflamed, doesn’t it make sense to temporarily eliminate the culprit that creates the inflammation?

Rather than guessing, with MRT, you’ll know exactly what foods to avoid temporarily and what foods not to worry about.

Inflammation goes down. You feel better. You live life more fully.

What can get better than that?

Since MRT can detect both type III and type IV hypersensitivity reactions, it’s your best bet for food sensitivity testing.

What About All the Other Types of Food Sensitivity Tests?

There are many food sensitivity tests on the market now and new ones seem to pop up regularly.

The main problem with these tests is a majority of them only test IgG levels and do not test type IV, cell-mediated reactions like the MRT test does.

Also, these other tests usually only test one type of white blood cell like lymphocytes, but they leave out an entire class of other cells like granulocytes.

These other food sensitivity tests are usually pretty low-cost but you get what you pay for:

  • you’re not getting the full picture of ALL possible food sensitivities
  • you may miss foods that cause an inflammatory reaction for you
  • keeping reactive foods in your eating plan will slow your ability to reduce inflammation
  • you get little to no guidance on how to best implement a personalized protocol

So remember – cheaper is not always better when it comes to food sensitivity testing – no matter how tempting it is or how slick their marketing is.

What About Elimination Diets?

Popular elimination diets such as “autoimmune paleo” or Whole30 usually eliminate common categories of foods like gluten, legumes, and dairy.

But again, even if you eliminate these, you may still be eating foods that are causing your symptoms.  

Even “healthy foods” like strawberries, lettuce, chicken, or sweet potatoes can cause mediator release and inflammation.

These popular elimination plans are not personalized to you and your blood chemistry.

You may feel better by eliminating dairy or gluten for example, but these foods might not be your biggest triggers when it comes to sensitivities.

As a result, your healing is slowed and you stop seeing results.

Bottom line?

Test, don’t guess.

What’s the Science Say About Food Sensitivity Testing?

Double-blind, placebo-controlled (DBPC) clinical trials are seen as the gold standard for most any type of experiment — including identifying adverse food reactions.

The aim of DBPC trials is to minimize outcome bias and the “placebo effect.” Neither the trial participants nor the scientists know who received the actual treatment or a placebo.

The problem with DBPC trials is they are expensive to run and they take a while to get the results.

Most of us don’t want to wait years to feel better – we want to feel better sooner rather than later.

As of this writing, there are no DBPC trials or peer-reviewed studies on the MRT test.

However, the methods used to run the test by Oxford Biomedical are backed by science.

Additionally, there are thousands of clients who have experienced relief from their symptoms after completing their personalized MRT protocol.

The good news is there are several other ways (other than DBPC trials) to know if something is backed by science or not.

Evidence-based practice is one way.

In the Journal of the American Dietetics Association March 2005 edition, they state:

“Evidence Based Practice uses the best available evidence, the results of peer-reviewed scientific studies, whenever possible, and, when the science is lacking, expert opinion and experience.”

The Academy of Nutrition and Dietetics states:

“Evidence-based dietetics practice is based on the best available evidence including research, national guidelines, policies, consensus statements, expert opinion and quality improvement data. Evidence-based dietetics practice involves continuing evaluation of outcomes which becomes part of the evidence base.”

Thankfully, trained clinicians and dietitian experts who offer MRT food sensitivity testing have countless testimonials from happy clients.

It is easy to see why the MRT test is so popular – because it makes a difference in patients’ lives!

Should You Do MRT Food Sensitivity Testing?

No test on the planet tests everything – this would be a very costly test!

However, with MRT, you’ll have a running start on knowing which foods are causing inflammatory mediators to be released in your body.

You temporarily remove those foods and this starts reducing overall inflammation.

You start to see fewer and fewer symptoms.

You start feeling better!

Remember, the foods you eliminate on your MRT plan are not meant to be avoided forever.

The Mediator Release Test (MRT), along with your personalized LEAP protocol from a trained dietitian will get you on your way to knowing which foods are best for you to eat RIGHT NOW.

With the MRT and LEAP protocol, you’ll get a customized plan for you and your lifestyle.

Testing helps to compress the time it takes for you to feel better.

There may be other aspects to consider when trying to reduce overall inflammation. This might include other types of tests (eg. stool, urine, etc.) and lifestyle modifications. All of this can be discussed during your sessions with your dietitian.

With MRT and LEAP, you’ll start addressing the root cause of your inflammation by uncovering the foods that cause symptoms for you.

Once you follow your customized plan, you’re on your way to achieving optimal health.

And that’s priceless!


Want to learn more? Click here.

If you have questions about the MRT food sensitivity test, book a free session with me to discuss.

-Caitlin Russell MS RDN CLT

I’ve found an approach to healing after the diagnosis that is life changing.

This transformed my life and I want to share it with you, too.

Are you ready to feel more empowered?

Order supplements through my Fullscript store.


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