So, you suspect you might have food sensitivities, but you're completely lost on which type of testing to get done.

MRT, ALCAT, IgG... your head's spinning with all these different acronyms. And you suspect your doc is kind of clueless to all this stuff, so you've just been scouring the interwebs to weed through as much info as you can on your own.

There's just one little problem: it's been kind of tough trying to distinguish between marketing hype from people who are just trying to sell you stuff vs. genuine, accurate info that could actually help you get to the bottom of your health issues. These tests can also be quite the investment, so you want to make sure that you're making the right call, am I right?

Completely understandable.

Let me shed some light on this dilemma for you.

First, let me make it clear to you what my associations are with these tests. I do NOT get compensated by companies to push tests. I choose to use the Mediator Release Test with my clients over other tests because of my own research and experiences with it. In fact, when I work with clients, I do not mark up the test at all (I generously pass my practitioner savings onto them to make it more affordable), so I am strictly getting compensated for my awesomeness in counseling and helping them get to the bottom of their health issues. I am not some sales rep or marketer; I'm merely a dietitian who is doing everything she can to help her clients find answers and get well.

Now that that's cleared up...


There are some similarities and some key differences between ALCAT and MRT that I'd like to take a minute to explain so you can make an informed choice if you decide to move forward with food sensitivity testing.

Same inventor

Both MRT and ALCAT were invented and patented by Dr. Mark Pasula, although ALCAT has been out of patent for several years now. (Dr. Pasula left the lab that performs ALCAT and he went on to create MRT.)

'Endpoint' tests

Both MRT and ALCAT test for 'endpoint' reactions.

Quick science lesson to help you understand this better: during a food sensitivity reaction, white blood cells release 'mediators', which are basically chemical weapons. These mediators are usually stored away under lock and key, so a certain set of circumstances need to be in place in order to unlock these 'weapons' (and your body feels the release of these weapons as symptoms).

What unlocks these weapons?


Mechanisms are basically the key keepers... and there are several different types floating around in your body. Some of the types of mechanisms could be IgG, IgM, immune complexes, T cells... any one of these could be involved in unlocking the weapons that cause your symptoms.

Some tests (such as IgG testing) only look for the presence of one key keeper when your blood is tested again different foods and chemicals, but if you're only looking for one key keeper, you're basically trying to put a puzzle together with most of the pieces missing. (Studies have also shown that the presence of IgG is not necessarily a good indicator of being sensitive to whatever food/chemical your blood is being tested against.)

Instead of looking for all the different key keepers, MRT and ALCAT look at the end result of these weapons being released (though they go about it in different ways... more on that in a sec). MRT and ALCAT don't care if it was IgG or IgM or T cells or whatever that showed up to the party; they just look for the aftermath... the clues that a party took place.

When the white blood cells release their chemical weapons, the physical size of the white blood cells change; they get smaller and more dense/compact as they release more and more weapons (kind of like a balloon leaking air).

ALCAT measures this response in your blood by measuring the changes in the size of white blood cells as they pass through an aperture (an opening). Unfortunately for ALCAT, their technology can't get an exact read on this shift in size because white blood cells aren't perfectly shaped little balls; they're kind of jelly-like, so the shape can change, which interferes with their readings. ALCAT also only measures each of the white blood cells once and it can't reliably distinguish between white blood cells and other things floating around in the blood sample (like red cell debris and other artifacts), so there's a lot of room for error.

MRT, on the other hand, goes about things a little differently by measuring the changes in the solids to liquids ratios. Since white blood cells release liquidy weapons during a food sensitivity reaction and then shrink down in size, the amount of liquids in a blood sample would take up more space while the solids would take up less space (changing the ratio). The more the ratio changes, the stronger the reaction. MRT also measures each reaction 1 million times, so there's much, much, MUCH less room for error.

And because MRT's technology is more sophisticated, it's able to show you the amount of inflammation (caused by the chemical weapon release) that your body experiences in the presence of the foods and chemicals being tested. This is something that ALCAT can't do because of the limits of their outdated technology.

ALCAT just lumps the foods and whatnot on your test results into 'green', 'yellow', 'orange', and 'red' categories (with 'green' being the safest to eat and 'red' being the most inflammatory)... but there's a big difference between something that's on the low end of 'green' vs. something that's borderline green-yellow. This may cause you to inadvertently eat things that are more inflammatory for your body.

MRT is able to quantify how much inflammation each food and chemical produces in your body... and it shows you this by depicting bar graphs next to each food/chemical. This provides a much clearer picture on which foods to start with (to reduce the most amount of inflammation/symptoms in the least amount of time).

Sample ALCAT & MRT Results

Because of the differences in testing (and the major limitations in ALCAT's technology), the diet protocol that goes along with ALCAT takes around 6 MONTHS to complete. In contrast, the diet protocol that goes along with MRT (called LEAP) takes roughly 4-6 WEEKS to complete (and, in my experience, most clients see between 50-80% improvement in symptoms within 10-14 days or so on LEAP).

So, with ALCAT, you're stuck on a pretty limited diet for months and you may never experience the type of improvement that MRT/LEAP provides (again, due to the limitations of their technology).

Bottom line: ALCAT was a good test when it initially came out (in the mid 1980s), but clearly, technology has advanced since then. MRT is basically a more sophisticated version of ALCAT and MRT produces much more accurate and reliable results.

If you'd like even more information on food sensitivities and testing, check out "The Patented Mediator Release Test (MRT): A Comprehensive Blood Test for Inflammation Caused by Food and Food-Chemical Sensitivities," by Dr. Mark Pasula (downloadable PDF file).

Testing shouldn't be your only consideration

I take things a step further with my clients to get them even better results: aside from using MRT to help guide the meal planning process, I incorporate my own science-y wisdom about food and nutrition into the mix. I also address other lifestyle factors that are sabotaging health (things that most other health practitioners wouldn't even consider). My model is more holistic, in that I look at the whole picture, not just an assortment of body parts or symptoms. This is absolutely paramount if you actually want to heal.

So, just know that testing won't solve all of your problems; it's how you use the test results (and your overall lifestyle) that really matters.

If you'd like to pursue MRT testing, check out my food sensitivity program page (all of my services are provided over the phone and online).