Debunking Food Sensitivity Tests

With endless food sensitivity testing options out there… where do you even begin? What in the world is an IgG, IgA, IgM, and MRT ??? There are a lot of terms out there for abnormal reactions to food – food allergies, food intolerances, food triggers, and food sensitivities. So what’s the difference and how is it impacting your gut health and migraine??


Differences Between Food Triggers, Sensitivities, and Allergies

Food Allergy: A food allergy is probably the most well-known food reaction but is also the least common – and most dangerous. When you eat a food you’re allergic to,  your body’s mast cells (part of your immune system) sense the presence of that food by using IgE antibodies. 

If you’re allergic to a food, you must avoid eating it to prevent adverse reactions. Food allergies likely aren’t causing your migraine symptoms, but if you suspect you have a food allergy it’s a good idea to see an allergist for further testing. 

Food Triggers: Food triggers that contribute to migraine pain are individual and different for everyone. It is thought that they might trigger migraine symptoms because they contain natural excitotoxins, or foods that can overstimulate your nerve cells. Food triggers do not involve your immune system and you may be able to eat a small amount without experiencing symptoms.

Food Sensitivities: Food sensitivities, like food allergies, involve your immune system. A major difference between the two is that while allergies have an immediate and often severe effect, sensitivities can take hours to days to cause symptoms that are milder and somewhat vague. 

When you eat a food you’re sensitive to, your body’s white blood cells (part of your immune system) are triggered directly and sound the alarm, causing widespread inflammation and a range of symptoms. While food allergies involve IgE antibodies, food sensitivities involve IgG, IgM, or IgA antibodies, or even just the food particle itself!


Do I Have a Food Sensitivity?

Not everyone with migraine has food sensitivities, although it’s a lot more common than you might think. 

If food sensitivities are contributing to your migraine symptoms, you likely have other issues going on like eczema, brain fog, fatigue, IBS, achy joints, depressed mood, diarrhea, anxiety, etc. Food sensitivities contribute widespread inflammation that can either cause these symptoms directly, or make conditions you’re genetically susceptible to (like migraine) spin out of control.

What causes Food Sensitivities?

While we don’t have the exact answer to this question yet, it is likely due to an issue with gut health. The most widely accepted factors that are thought to contribute to food sensitivities include:

  • Poor digestion of food
  • Imbalanced gut bacteria
  • Chronic stress
  • Infections from parasites or h. pylori
  • Low stomach acid
  • Limited diet

How do I test for Food Sensitivities?

Start with finding a dietitian (this is me!!!) who is certified as a LEAP CLT (Certified LEAP Therapist). This certification was created to provide dietitians expert training in identifying and managing underlying food sensitivities.

Although there are SO many food sensitivity tests out there, CLT’s order a ‘Mediator Release Testing’ (MRT) functional nutrition test. This test measures your immune reaction to over 170 different foods and the chemicals in them.

Why MRT Testing?

MRT is considered the ‘gold-standard’ of food sensitivity testing. When you eat a food that you’re sensitive to, your immune cells release mediators (such as cytokines, prostaglandins, or leukotrienes) through a non-allergy reaction.  These mediators have been found to cause unwanted symptoms such as brain fog, pain, hives, digestive issues, skin irritation, etc.,

How I Treat Food Sensitivities in my Practice as a CLT Dietitian

My favorite holistic approach to testing for food sensitivities is a two method approach:


Step 1: MRT Food Sensitivity Test
Step 2: Temporary elimination/reintroduction protocol
Step 3: Getting to the root cause!

Food sensitivities are caused by underlying issues that affect your ability to process food properly. When we can find the cause (Leaky Gut Syndrome, Gut Bacteria Dysbiosis, etc) – we can start to work on healing and raising your migraine threshold!

I do NOT recommend using the food sensitivity tests available through the internet that test IgG only – these are not helpful and can lead you in the wrong direction. 


I want to hear from you – are you having a difficult time deciphering messages from your body? Have you tried what feels like every elimination diet but don’t know why your food sensitivities are getting worse? Have you tried talking to your doctor about your concerns? Let me know in the comments or join the conversation with a community of fellow migraineurs on Instagram HERE.

Want more support managing migraine using a gentle, holistic approach? Click HERE to learn more about how I can help!

Reviewed by Kelli Yates, RD, LD, CLT

Published by Kathryn Darsillo, B.S Nutrition & Dietetics, Dietetic Intern

Kathryn Darsillo, is currently a Dietetic Intern with Lenoir-Rhyne University and has a Bachelors of Science in Nutrition and Dietetics in addition to having an Associates Certificate of Completion in Culinary Arts, and is also a fellow migraineur!

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