This is THE guide to food sensitivity testing I wish existed when I was debating whether to use a food sensitivity test.
When my husband was diagnosed with two autoimmune diseases I searched in vain for some down to earth, accurate, and evidence-based information on food sensitivity tests.
It did not exist.
To save you oodles of time, money and frustration, please allow me to lay out ALL the different tests you might come across, with the pros, cons, and research behind each.
Let’s be honest, when you “research” online, the information you are likely to get is from the company selling the test, and of course they will all tell you it is the best, share some fancy-sounding technical jargon, and sprinkle a handful of testimonials on top.
Or you may find an article from a practitioner that is really only experienced with ONE type of test or diet, and they wholeheartedly make recommendations or warnings based on this limited experience.
Here I have reviewed the science and research for EVERY SINGLE TEST method I could find.
But, I will also include the experiences of my husband and clients with various methods… in case you care about my two cents.
Long story short, we ended up trying several different approaches, including three diets and two food sensitivity tests.
Only one helped my husband, but it helped a lot:
- 80-90% improvement in his joint pain
- He no longer struggles with essential requirements of his job (mounting a horse, and carrying heavy stuff like mineral tubs)
- He is able to do things he enjoys, like rough-housing with our kids and basketball
- Severe reflux and swallowing problems have disappeared
- Way fewer migraines
Disclaimer: I did end up getting certified to offer the test method that I recommend in this article. However, at the time of writing this article, I am not even taking clients and have nothing financially to gain from recommending it. I just think it is the best, it helped us a ton, and I want other people to know about it. In the future, I may start taking clients again, but I would never offer a service I didn’t think was super helpful.
What are the Symptoms of Food Sensitivity?
- Fatigue (exhaustion)
- Malaise (feeling “under the weather”)
- Stomach ache
- Digestive upset
- Muscle pain
- Joint pain
- Brain fog
- Water retention
- Unexplained weight gain or loss
What Diseases are Linked to Food Sensitivity?
Both types of food hypersensitivities are linked to a wide range of chronic diseases such as:
- Irritable bowel syndrome (5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
- Migraine (5, 6, 8, 16, 17, 18, 19, 20, 21)
- Inflammatory Bowel Disease (Crohn’s and Ulcerative Colitis) (5, 10, 22, 23, 24, 25)
- Dysmenorrhea (menstrual cramps) (10)
- Epilepsy (5, 26)
- Uticaria (6)
- Gluten enteropathy (6)
- Eczema (5, 6, 28, 27)
- Asthma (6)
- Eosinophilic Esophagitis (6, 46)
- Food Protein-Induced Enterocolitis Syndrome (FPIES) (6)
- Acne (5, 29)
- Psoriasis (5, 30)
- ADHD (5, 31, 32, 33, 34)
- Autism (5, 35, 36)
- Chronic fatigue syndrome (5, 37)
- Depression (38)
- Fibromyalgia (39)
- Gastroesophageal reflux disease (GERD) (5, 40, 41)
- Interstitial cystitis (5, 42, 43)
- Rheumatoid arthritis (5, 44, 45)
- Heiner syndrome (46)
As a dietitian, my personal clients have seen food sensitivity testing or elimination diets improve:
- Arthritis, both rheumatoid and psoriatic
- polycystic ovarian syndrome (PCOS)
- Irritable bowel syndrome (IBS)
- Ulcerative colitis
- GERD (gastrointestinal reflux disease)
- reflux and colic in babies of nursing mothers
- Depression and anxiety (both mild and severe)
- and more….
How Do Food Sensitivities Develop?
At this time, it seems that food sensitivities develop, in part, when leaky gut is present.
Leaky gut is when the lining of your intestines is damaged. Holes in your normally tight lining now allow partially digested food particles that would not normally be absorbed to enter your blood stream.
These abnormally large food particles are not recognized by your immune system. If your white blood cells decide they don’t like them, they will mount an immune response, causing inflammation and lots of problems. Since the food has entered your circulating blood, the problems can pop up anywhere in your body.
Lots of Americans probably have leaky gut due to our typical diet, which is high in sugar, and lacks fiber and probiotic foods. Also many medications and food additives and chemicals can enhance leaky gut.
You may not be able to get rid of food sensitivities without healing leaky gut, and you may not be able to heal leaky gut without getting rid of food sensitivities (since the constant attacks from your immune system can cause continuous damage to your gut lining).
So identifying your sensitive foods, removing them for a time to allow healing, and working on other gut healing habits in the meantime is super important.
How are Food Sensitivities Different Than Allergies?
First, understand that food sensitivities are a totally different animal than food allergies.
To throw a wrench in your attempts at research, there is no standardized language for food sensitivities. You will hear them referred to as everything from hypersensitivities, to IgG food allergies, to non-IgE allergies, to food intolerances, to adverse food reactions. It can be really confusing.
Below is the terminology I find to be most clear and accurate. I like it because it also clearly highlights the several different ways you can have an adverse reaction to foods:
Food Allergy (Type I Reaction)
An immune reaction caused by IgE antibodies that happens within a few minutes to a few hours after consuming food.
When IgE identifies a food as dangerous, it signals your white blood cells to release histamine and other inflammatory chemicals. Your body reacts with redness, swelling, hives and other symptoms common to allergies.
Some allergic reactions can be strong enough to be life-threatening.
90% of allergies are caused by 8 foods, which makes them easier to pin down with a simple food and symptom diary. (46)
Food Allergy Tests
Your doctor may want to use a test to help identify if food allergies are the problem.
The following methods are recommended to diagnose food allergies by the
Oral Food Challenges are the gold standard for diagnosing food allergies, or confirming suspected allergies from a skin prick test.
Under your doctor’s supervision, you eat a diet containing only a few presumably safe foods (like lamb and rice) to wash out any previous symptoms. Then you introduce one food (and one placebo) at a time in capsule form, with neither you nor your doctor knowing what the food is (this is called “double blind”) until symptoms are recorded.
This is effective, but time-consuming, difficult, and not always practical.
Elimination Diets where certain foods are removed from your diet for a time to assess whether food allergy symptoms disappear can be helpful. This approach is especially recommended when food sensitivities are suspected.
Skin Prick Test can be helpful in narrowing down options, but is not diagnostic of food allergy by itself. A small sample of a suspected food is placed on your forearm or back, and then your skin is pricked with a needle so that some of the substance can penetrate your skin. The idea is that if you are allergic to the food, it will cause a raised bump (5).
Serum IgE Blood Test cannot be used to diagnose, but can be useful to identify potential triggers. It measures the levels of IgE you produce when exposed to different foods. Research shows that the presence of IgE may be a sign of tolerance, not intolerance, by your immune system (similar to IgG) (48, 49).
Food Sensitivity (Type III or IV Reaction)
These are also immune reactions to foods that can be delayed for hours or days after eating the offending food.
They often occur when a leaky gut is present, allowing partially digested food components to slip into your blood stream and be “seen” by your systemic immune system.
The reaction can happen anywhere in the body, and the symptoms vary widely, anything from headache, to joint pain, to tummy troubles.
This type of immune reaction can be caused by two pathways:
Type III Reaction- Antibody Mediated Reaction
These reactions are caused by antibodies such as IgG and IgM.
Most tests measure IgG levels. However, having IgG markers for a particular food can also be a sign of tolerance by your immune system.
Remember if IgG signals white blood cells to release chemicals like cytokines, and prostaglandins then you will have symptoms. IgG itself does not cause symptoms.
This is a main shortcoming of most food sensitivity tests that use antibodies like IgG!
Type IV Reaction- Direct Cell Mediated Reaction
Sometimes T cells just decide to attack certain food components without any signal from the antibodies. This is called a direct cell-mediated reaction.
T cells will signal other white blood cells to release all sorts of inflammatory chemicals, causing symptoms all over the body.
Studies show many chronic health problems are likely caused by Type IV reactions, not IgG.
This is why you want a test that captures both Type III and Type IV reactions. I’ll explain which tests do this below!
This is not an immune reaction but a lack of proper enzymes to digest a certain food. The best known example is lactose intolerance, where a person does not make enough of the lactase enzyme to digest the lactose sugar in milk, which causes gas, bloating, pain and diarrhea (50).
Another example is histamine intolerance, which could be caused by a deficiency in diamine oxidase enzyme (DAO), so that the histamine in food doesn’t get broken down. This build up of histamine could cause allergy-like symptoms such as headaches, sinus congestion, and hives. (51).
Food Intolerance Tests
Lactose intolerance can be confirmed with a breath test, though many doctors will just advise you to avoid it if you have symptoms while eating dairy.
Conclusion: Food sensitivity reactions are very different than allergies or intolerances. Current evidence suggests that if problem foods can be pinpointed and eliminated, disease symptoms will improve.
Choosing an Accurate Food Sensitivity Test
If you decide to use a food sensitivity test, you will want one that captures ALL pathways (Type III and Type IV).
Most popular tests today are based on IgG. But these identify only part of one type of pathway. Plus IgG itself can also be a marker of tolerance.
It is super important to realize that food sensitivity symptoms are not caused by the presence of IgG, but by the eventual release of chemical mediators like histamine, leukotriences, prostaglandins and about 100 others, that actually cause the inflammatory response.
This may be why food sensitivity testing gets a bad rep among some healthcare practitioners. Many are only aware of IgG tests and realize that they have some weaknesses.
Let’s take a look at which test methods make the most sense.
The Best 4 Food Sensitivity Testing Methods
These are the 4 methods that have the strongest evidence base. We will explore 7 other “options to avoid” later on.
If you’d rather skip all the sciencey stuff, check out this chart which quickly summarizes all 4 best food sensitivity test options. Click on the hyperlinks to jump to the section detailing that method.
|METHOD||Easy-to-read Results?||Overall Accuracy||Captures Type III & Type IV Reactions||Scientific Backing||Cost|
|Elimination Diets||NA||Medium||Yes||High (depending on method)||Low|
|MRT *My Fav||Easy||High||Yes||High (newest tech)||$695|
|ALCAT||Medium||High||Yes||High (older tech)||$1,115|
(Click the hyperlinks to jump to a more detailed explanation of that test.)
If you want MORE sciency stuff, I recommend this excellent article: “Food Sensitivity Testing: Which Test is Best?”
Warning: If you have any history of an eating disorder, any type of restrictive diet, such as those suggested below, can be a trigger for some people. I recommend working with a dietitian who specializes in BOTH eating disorders and whichever food sensitivity test method you choose.
So… What is the Best Food Sensitivity Test?
Based on common sense, the science behind it, the limited research available, expert opinion, and personal and professional experience…
(Drum roll please…)
The only food sensitivity test that I ever recommend now is the MRT (mediator release test).
Here is why:
- Elimination diets alone, not guided by testing can be restrictive and discouraging.
- There are many food sensitivity tests being advertised right now, but the Mediator Release Test most accurately catches ALL Type III and Type IV immune responses. (IgG-based tests, the most popular tests, capture only a portion of type III reactions.)
- Research and logic does not support any of the other testing methods besides ALCAT and MRT. The testing method is similar in these tests, but the MRT uses updated and more precise technology.
- The MRT comes with clear, easy to read results.
- The MRT goes hand in hand with a highly effective elimination diet called LEAP that helps improve symptoms by about 70% in the first 2 weeks.
- My husband’s psoriatic arthritis saw an 80-90% improvement in just a few weeks- after many other methods failed.
- Dozens of my clients since have seen huge improvements in their symptoms using the MRT test.
- Resources like LEAP, Certified LEAP Therapists, private Facebook communities, Pinterest boards, and websites make it easier than ever to use the LEAP/MRT test.
4 Best Food Sensitivity Testing Methods
Reference the chart above for a quick summary of these methods.
Method #1- Elimination Diets & Food Challenges
Currently what is still considered the “best” method by the National Institute of Allergy and Infectious Diseases (NIAID) is not a test at all but a diet approach. They recommend the following methods for identifying food immune reactions:
Oral Food Challenge is the gold standard. Working with your doctor, you consume a very limited diet for a few days of about 3 presumed safe foods. This is known as an “oligoantigenic diet”. This should clear up any symptoms caused by food.
Then you systematically introduce one food (and one placebo) at a time in capsule form. Neither you, nor your doctor knows what food is being introduced until symptoms are recorded (double-blind).
The oral food challenge is effective at identifying reactive foods, but not very practical for food sensitivities.
Since you could have a hypersensitivity reaction to nearly anything, it could take many months to reintroduce every food ingredient you normally consume, and your diet would be very limited during this time.
Food Elimination Diets are the next most useful tool recommended by the NIAID, especially for identifying food sensitivities.
One or more foods are eliminated from your diet for a time to see if symptoms improve, and then re-introduced one by one to identify which foods cause symptoms.
Problem foods continue to be eliminated, while non-problem foods can be eaten again.
However, you basically have to guess at which foods are causing problems and try eliminating those. If you are way off the mark, you probably won’t feel much better.
This is where I find it really helpful to guide which foods you eliminate with either:
- A proven diet protocol
- A food sensitivity test backed by science
Let’s explore those options next.
Autoimmune Protocol or Autoimmune Paleo Diet (AIP)
The AIP diet has gained popularity over the last few years and even has some research to back it. The diet involves removing the top 8 allergens (milk, eggs, fish, shellfish, tree nuts, peanuts, wheat and soybeans) from your diet, plus a number of other commonly reactive foods, such as all grains (including corn), nuts, seeds, and nightshades.
Advantages of this approach to food sensitivities:
- Potentially less costly than testing
- Supported by peer-reviewed studies
- Popular, so there are lots of resources, recipes, and cookbooks to help you implement it
Disadvantages of AIP:
- Usually more restrictive than elimination diets based on testing.
- Takes longer to work through sensitivities since you are just guessing.
- It is not personalized to your sensitivities. The AIP diet is simply covering all the bases and eliminating ALL commonly problematic foods.
- You can have an immune reaction to just about any food, not just those eliminated in this diet, so you may not get better.
What is the Evidence for the AIP Diet?
- 73% of patients with Crohns or Ulcerative Colitis achieved clinical remission after 6 weeks in one study using AIP. (52)
- Hashimoto’s Thyroiditis quality of life, symptoms, and inflammation were greatly improved in 10 weeks following an AIP diet. (52).
- Improvements to blood pressure, blood sugars, lipid profiles and heart disease risk have been observed using a Paleolithic Diet (53).
- A Paleolithic Diet improved blood sugars more than a Mediteranian-style diet in this study (54).
- Over 3 months, a paleolithic diet improved blood sugars and heart disease risk factors better than the standard diabetes diet. (55)
Low FODMAP Diet
The Low FODMAP diet is only recommended for people with IBS at this time.
FODMAP stands for Fermentable Oligo-, Di-, Mono-saccharides and Polyols, which are all types of carbohydrates that can be difficult to digest and cause digestive issues like pain, bloating, gas, and diarrhea (56).
- Many fruits such as apples, plums, cherries, peaches, plums, and watermelon
- Many vegetables such as cauliflower, brussel sprouts, asparagus, and snow peas
- Many sweeteners
- Some dairy
What is the evidence for the Low FODMAP diet?
Dozens of studies have been published on this diet showing reduced digestive symptoms and improved quality of life for people with IBS. It also seems to be effective long-term even after the re-introduction and personalization phases of the diet. (59,60,62,61,63,64,65,66)
After the restriction period of 3-8 weeks, you can try systematically re-introducing high FODMAP foods to see which you are still sensitive to.
Again, this diet is only recommended at this time for those with IBS. If you have another condition and suspect food hypersensitivities, I would try one of the other methods.
Low FODMAP Resources
Low FODMAP Resources from dietitian Kate Scarletta.
Lifestyle Eating and Performance (LEAP)
LEAP is a dietary approach that is really more like a hybrid between diets and testing.
Rather than starting with 3 presumed safe foods, LEAP begins with 20-30 safe foods personalized with your results from a test called Mediator Release Test (more on this below).
I like it because it takes the oligoantigenic diet approach recommended by NIAID. But it is personalized and less restrictive because it is based off of your unique immune response.
**LEAP/MRT is the diet/test that finally made an immense difference in my husband’s psoriatic arthritis and acid reflux.
I have since used LEAP with dozens of clients and patients with really great results. I know hundreds of other dietitians who use it with great success for themselves and their patients.
My Experience with Elimination Diets
The FIRST experiment I tried to help my husband’s autoimmune diseases was an elimination diet. He did feel a bit better on the diet, but it was very discouraging for him to eat this way as a newby to elimination diets.
Even though we only eliminated 4 items (wheat, dairy, corn, and soy), he didn’t know what to eat and felt like he was starving all the time.
He only maintained this eating pattern for about 6 weeks before lapsing back to his old, comfortable eating habits. The improvements he felt were not significant enough to motivate him to keep eating in a restricted fashion.
In the end, getting test results with “proof” he could see of what was causing an immune reaction was easier for him to follow and stay motivated to stick with.
Method #2- Mediator Release Test (MRT)
The Mediator Release Test was developed by immunologist Mark Pasula using a patented impedance technology. This test can only be ordered from Oxford Biomedical Technologies.
MRT measures your immune response to 141 foods and 29 chemicals (170 total antigens) using a blood sample. It then quantifies the total amount of chemical mediators (the histamines, leukotrienes, prostaglandins, etc. that cause actual inflammation and symptoms) that are released when your blood is exposed to each of these types of foods.
Advantages of MRT include:
- Captures all Type III and Type IV immune responses, because it is not just looking at IgG. This is a major advantage of MRT over other testing methods.
- It greatly reduced my husband’s joint pain, acid reflux, swallowing difficulty, and migraines, when other methods did not.
- Results are paired with a clear diet plan called LEAP.
- Thousands of dietitians use MRT/LEAP and report an average 70% symptom improvement in the first 2 weeks. Patients can return to more “normal” diets within 3-6 months without symptoms.
- Oxford Biomedical, is a CLIA accredited lab which must pass quality control measures biannually (nowleap.com).
- The MRT comes with easy-to-read, color-coded results that make it easy to see which foods and chemicals are a problem.
Disadvantages of MRT are:
- It is more expensive than most IgG tests ($695 if ordered directly from Oxford Laboratories), but less expensive than the ALCAT test.
- There is no peer-reviewed research at this time, but studies will soon be published!
MRT & LEAP DIET:
Patients who order through a functional dietitian who is trained as a Certified LEAP Therapist (CLT) see an average 70% improvement in symptoms in the first 2 weeks. Those who order a test without the support of a CLT don’t have as much success. I HIGHLY recommend the extra expense of hiring a CLT. It’s priceless.
The LEAP diet is a personalized anti-inflammatory diet created for you based off of your MRT results. Your CLT can help you apply the LEAP diet, and recommend other nutrition therapies and supplements to get the maximum healing for your efforts.
The goal is to help you improve your symptoms quickly, and then expand your diet as soon as possible without symptoms returning. Your CLT will help you troubleshoot and eat with as little restriction as possible to help you get better quickly.
What is the Evidence for the MRT Test/LEAP diet?
We have a lot of evidence that food sensitivities are a problem in many chronic conditions, but so far there is very little research for each food sensitivity test.
Here’s what we do know about MRT:
- Reduced IBS Symptoms by 53% in one month (5)(68) in one study (when paired with LEAP diet).
- Boasts a 94% sensitivity and up to 91% specificity which basically means it is very accurate, with very few false negatives, and very few false positives (69).
- 90% split-sample reproducibility, which means that when the MRT was performed twice on the same sample of blood, the results matched ninety percent (70)(71).
- See the studies below for the ALCAT which uses similar technology as MRT.
As a dietitian, it’s important to me to use “evidence-based” strategies, which means I use “the best available evidence, the results of peer-reviewed scientific studies, whenever possible, and, when the science is lacking, expert opinion and experience” (67).
While there is no peer reviewed research at this time, studies will soon be published using MRT/LEAP for:
- Polycystic Ovarian Syndrome (PCOS),
- Irritable Bowel Syndrome
- migraines, and
- hidradenitis suppurativa.
I will definitely update you when those studies are published.
The science behind the test makes sense. But peer-reviewed scientific studies are lacking to date, so I take into account the experience and opinions of experts in the area.
Thousands of dietitians working with tough chronic conditions and autoimmune diseases see great results (including myself). Typical results reported using the Mediator Release Test combined with LEAP diet are:
- 70% improvement in symptoms in the first 2 weeks
- Continued improvement thereafter
- Restored oral tolerance within 3 to 6 months (meaning foods that once caused problems can now be eaten without provoking symptoms).
My Experience Working with the MRT/LEAP Test
Because it seemed like the best food sensitivity testing option from what I could gather, we decided to try it out for ourselves.
My husband went from limping around, being too sore to run, rough-house with the kids, or play basketball to having an 80-90% improvement in his psoriatic joint pain. We also saw some great “side benefits” like improved energy, reduced migraines, and the disappearance of severe acid reflux that made it difficult to swallow his food.
A Note for Fellow Dietitians
In your research, you may have come across a statement from the Academy of Nutrition and Dietetics (AND) that “current evidence does not support use of the mediator release assay (MRT test) for diagnosing a food allergy (72).” Which is true. It is only useful for identifying food sensitivities, which are very different from allergies.
If you are a dietitian, this statement may have caused you to instantly dismiss the MRT. This statement was concerning to me as well before I fully understood the difference.
The AND also states: “Food allergies, food sensitivities, and food intolerances are an evolving area of practice. The recently published practice paper is clear in only addressing food allergies, which are the best defined and have the most evidence for practice.” And that “practitioners who use MRT must weigh the risks and benefits of this strategy (72).”
The potential benefits of MRT easily outweighed the risks for us. The risks of doing nothing were permanent joint damage and disability. The risks of conventional medications were not acceptable either.
It was worthwhile for us to venture on a method with less evidence, but that scientifically made sense and had been used with success by my peers. Many of your clients will feel the same way we did.
If no practitioner ever tried to find solutions to our clients’ problems in unconventional ways, how would we ever know where to focus new research? How would we ever advance our patient care?
We should use our expertise and clinical judgement to be on the cutting edge of new therapies and elevate the status of dietitians as the nutrition professionals.
Method #3- Antigen Leukocyte Antibody Test (ALCAT)
The ALCAT from Cell Science Systems was also developed by Dr. Pasula in the 1980s. Like the MRT, it requires a blood sample and measures the amount of mediators released from white blood cells when exposed to different foods.
The advantages of this test are that it:
- identifies both Type III and Type IV reactions, not just IgG.
- tests for a large range of antigens: up to 474 foods, herbs, chemicals, medications, and even molds (73).
- has some peer-reviewed research to support it.
- the lab is CLIA certified (73).
The disadvantages are:
- it uses older impedance technology than the newer three-ribbon MRT method (5),
- the results are not as user-friendly, showing only 4 broad categories of reaction, rather than the visual, color-coded bars with a more precise degree of reactivity.
- It does not contain a specific diet therapy like MRT/LEAP.
- It is more expensive than IgG and MRT (up to $1115, although this does include 2 video consults with a “nutrition advisor.”)
What is the Evidence for the ALCAT?
There are peer-reviewed and non peer-reviewed studies supporting the ALCAT.
- An ALCAT-based elimination diet improved IBS symptoms more than a low FODMAP diet in a 2017 study (76).
- ALCAT pinpointed non-celiac gluten sensitivity as well as a double blinded food challenge (77).
- An avoidance diet based on ALCAT significantly improved symptoms of migraine, eczema, and rhinitis (73).
- 70% of foods that tested reactive on ALCAT also stimulated an enhanced DNA release from white blood cells (which would cause an immune response) (78).
- ALCAT has 79% sensitivity and 87% specificity for foods (74), which basically means it is pretty accurate at catching food sensitivities, though not nearly as accurate as those published for MRT. Another study showed slightly lower, but similar results (79). For food additives specifically, the accuracy was even better (75).
Method #4- IgG Food Sensitivity Tests
If you’ve seen an ad for a food sensitivity test, it was probably for an IgG-based test. They are being marketed heavily right now.
These tests also require a blood sample, which is then tested at the laboratory for IgG antibodies using the ELISA or RAST methods.
Many different companies offer this type of testing. The laboratories used and the exact methods vary by company, with some offering higher quality testing than others.
IgG Testing Options include:
- Everly Well (IgG to 96 foods)
- Meridian Labs (IgG & IgE but doesn’t specify which causes reaction; 189 foods tested + candida)
- KBMO FIT test (IgG & compliment, 132 foods, chemicals & candida)
- Pinnertest (measures 200 foods, but website isn’t clear how; site studies on IgG but then talk about “enzyme deficiencies” and “permanent intolerances”.)
- Genova (IgG4 to 90 foods)
- Cyrex (various foods and chemicals, IgG, IgA, and/or IgM depending on the antigen)
- Dunwoody Labs (IgG, IgG4, IgE, + Complement)
- Alletess (IgG & IgA for up to 184 foods)
Some of these labs have a more sophisticated methods that test not only IgG, but also IgG4, compliment, IgA, or IgE (allergies) in an effort to be more comprehensive or accurate.
In my view, IgG will always be an inferior testing method because it has two main flaws:
- It only tests for antibodies (Type III), which means they are missing all cell-mediated (Type IV) reactions. Many chronic conditions are linked with Type IV reactions. Unless you only have IgG responses (unlikely), these tests will miss some major sensitivities that could be key to your recovery.
- The second major flaw is that just because a food tests positive for antibodies like IgG doesn’t mean you have an immune reaction to it. Research shows that IgG is likely a marker of tolerance as well as intolerance. So testing IgG alone is ineffective. These tests are made slightly more effective by adding in things like IgG4 or compliment, but the first flaw still remains.
What is the Evidence for IgG Tests?
There is some peer-reviewed research supporting IgG testing for migraines and IBS:
- Diet restriction based on IgG resulted in fewer migraine headaches (80)
- A diet based on IgG improved IBS symptoms by 26% (81)
- Migraine and IBS were reduced in concomitant suffers following an IgG-based elimination diet (82).
In addition, I know of practitioners using IgG testing with good results. It makes sense that someone whose symptoms that are caused primarily by IgG hypersensitivities would see some improvement.
This could also be because IgG tests are more likely to be positive for foods you eat a lot of, so eliminating your most commonly consumed foods, just by chance, is more likely to eliminate the problem foods.
However many other studies and reviews are finding that IgG-based tests don’t get significant results.
My professional opinion is that they would see larger improvements with the MRT test which would capture all sensitivities.
My Experience with IgG Testing
A few months before we had the MRT test done, my husband’s health care provider recommended he get a food sensitivity test from Meridian Labs.
My husband’s IgG test results ended up saying he was really reactive to many of the foods he eats a lot of such as beef (he manages a beef cattle ranch). His diet was really difficult to follow because of that.
You are more likely to have IgG antibodies to foods you eat more often, even though you may not actually have a damaging end-point immune reaction where your WBCs release inflammatory chemicals (the things that cause all the negative symptoms).
Conclusion: IgG tests may be effective at catching some types of food sensitivities, but will miss others, and can also give false positives. While they are less expensive than MRT or ALCAT, they are also less effective.
7 Food Sensitivity Tests and Diets to Avoid
There are several more tests you may come across. I don’t recommend the following as they don’t have sufficient evidence to support them at this time. This is not to say they are all useless, but I just can’t be sure.
I don’t dive deep into any of these testing methods since I don’t recommend them, but if you want more in depth info on each, I recommend this excellent article: “Food Sensitivity Testing: Which Test is Best?”
1. Applied Kinesiology (Muscle Testing)
- Practiced by nearly 40% of chiropractors (96).
- Performed by having you hold a vial of the test substance in one hand while extending your other arm out, perpendicular to the ground. Force is applied to the extended arm, and if it weakens, then it is believed you have a negative reaction to that substance. If your arm stays strong, it is okay for you.
- It is based off the premise of energy pathways or meridians in the body.
- There are many anecdotal reports of its usefulness (5).
- Research thus far has not proven this method reliable for identifying food sensitivities, allergies, or poisons (97, 98, 99) .
2. Vega Test or Electrodermal Test
- Uses “electroacupuncture,” which sends an electric current through your body.
- The idea is that when your body is exposed to a food or substance it does not “like”, it triggers a subconscious nervous system response that changes the way electricity is conducted through the skin (86).
- Has been tested for food allergies, with varying results. There is no published data I am aware of for food sensitivities (86, 87, 88, 89).
3. Hair Testing
- Although it may be simpler to mail a hair sample to the lab than a blood sample, there is currently no validated method for hair testing.
- Studies have been low-quality with inconsistent results (90, 91, 92, 93, 94).
- Research and methods for hair testing for food sensitivities needs more development at this time.
4. Leukocyte Antibody Test
- A blood test that measures about 500 antigens including food, additives, mold, medications, and herbs.
- ELISA/ACT Biotechnologies is not upfront about how the test is performed.
- There is one peer-reviewed study showing an improvement in fibromyalgia symptoms using this test (83).
More research and more up-front information to explain the science behind this method is needed before I could confidently recommend this method.
5. Cytotoxic Testing
- A blood sample is placed on slides with various food antigens on them, then examined under a microscope to look for damaged or dead cells. The idea is that this would indicate food sensitivity.
- There is a lot of room for error, and no evidence that this is an accurate way to identify either food allergy or sensitivity (5).
6. Live Blood Analysis (LBA) by Darkfield Microscopy
- This technique is a valid method for examining blood cells and finding certain types of bacteria in the blood.
- There is no research to suggest it should be used for the evaluation of food sensitivities (5, 84, 85).
7. Coca Pulse Test
- Pulse testing for food allergies and sensitivities was introduced by Dr. Arthur F. Coca in 1956 after he noticed his wife’s chest pain and pulse rate increased after eating certain foods (95).
- He reported using this method to detect food sensitivities in his patients with great results.
- While it is known that certain food reactions can increase pulse rate, many sensitivity reactions don’t happen for hours or days. And many factors can increase pulse rate besides food, including your thoughts.
- It is probably not a very reliable food sensitivity test method.
How Do I Order a Mediator Release Test (MRT) Kit?
You can order this test in two ways:
- Through any Certified LEAP Therapist (a registered dietitian who also has many hours of additional training and experience in food sensitivity and chronic disease). I am a CLT. You can learn about my program here.
- Order directly through Oxford Biomedical at www.nowleap.com. (I don’t recommend this option. See below.)
Though it will cost more money, I do think working with a Certified LEAP Therapist is worthwhile for several reasons:
- Those who work with CLTs see an average 70% reduction in symptoms in the first 2 weeks, with continued improvement thereafter, and can return to eating many “problem” foods without symptoms in 3-6 months.
- Many CLTs will offer an initial consultation for a very low price, and give you honest advice on whether or not the test would be helpful for your circumstances, before you spend big money.
- You can sometimes order the test at a discounted price as part of a package deal with your CLT.
- Food sensitivities are tricky, even with testing, and a CLT can help you interpret your results to be most effective for your disease and symptoms.
- Your CLT will provide a clear plan and accountability to help you stick to and work through your diet plan effectively and systematically over the course of a few months.
- CLTs are also dietitians, usually with functional medicine experience. He/she knows how to help your disease with other strategies besides JUST the food sensitivity test.
- You can get access to a private Facebook community of other people doing LEAP testing.
- Your CLT will help you create a diet plan based on your results that works best for you.
- Sorry to say… but very few people will successfully work through this full protocol without someone to guide them and meet with them regularly. I know you think you will be the exception… but will you really? Just spend the money once and do this right!
Step-by-Step Plan for Food Sensitivities
Before you even order a food sensitivity test, you should definitely get a few solid habits in place. For several clients, these basics cleared up their symptoms enough that they didn’t even NEED food sensitivity testing.
Either way, if you don’t have these basic food medicine habits in place, you will not achieve long-term healing, even with the best food sensitivity test! So start here!
- Choose one of these habits to focus on each week. Many of these are covered in the FREE Heal with Food Fast 5 Day Action Plan. Or join my Food Medicine Jumpstart 4 Week Course for extra support getting these habits in place quickly.
- Eat 80% “real” food, meaning most of your food is fresh or has a short ingredients list with things you recognize as food. No chemicals, food dyes, additives, preservatives, etc. Buy organic when you can.
- Up to 20% of your food can be “play” foods.
- Balance your meals and feel full for longer by including a PFC (protein, fat, carb) at every meal.
- Follow a low sugar lifestyle. Women and kids can shoot for 25 grams of added sugar most days, men can aim for 36g per day (natural sugars in fruits and milk don’t count).
- Strive for 5 cups of fruits and vegetables every day. A variety of color will give a variety of nourishing and detoxing goodness.
- Feed the friendly bacteria in your gut with probiotics foods daily like yogurt, fermented veggies like sauerkraut or beets, and fermented drinks like kefir and Kevita.
- Drink plenty of water daily. I usually recommend 64 ounces.
- You will likely notice a big improvement in your symptoms as you apply each of these basic steps. To help you, grab the FREE 5 Day Action Plan.
2. If you need more help, set up a consultation with a Certified LEAP Therapist. Many can work from a distance or virtually, so expand your search if you can’t find one locally. I am a CLT and work with clients virtually.
3. Order your MRT test kit and follow your LEAP protocol with dedication for the next several weeks. Enjoy your discoveries and further improvements!
4. If you don’t feel 80% better, continue working with a functional dietitian or doctor. Other root problems such as nutrient deficiencies (very common) or bacterial or fungal overgrowths could be at play!
Keep in mind that you shouldn’t have to live perfectly in order to feel good. If you find yourself feeling crummy at the slightest slip-up, something else is wrong beyond food sensitivities, and you should take the next step toward addressing that.– Heather Hall, RDN, LD, CLT
There are many food sensitivity tests being advertised right now, but the Mediator Release Test is the best because research, clinical experience, and science support the use of the MRT far and above any other method currently available.
The MRT comes with clear, easy to read results.
The MRT goes hand in hand with a highly individualized oligoantigenic diet called LEAP that helps improve symptoms by about 70% in the first 2 weeks.
My husband’s autoimmune condition saw an 80-90% improvement in just a few weeks after many other methods failed.
Nearly all of my dozens of clients have seen huge improvements in their symptoms using the MRT test.