food allergy versus food sensitivity

The world of adverse food reactions is large, complex, and confusing. There are many differences and similarities between a food allergy and a food sensitivity. The two conditions can briefly be explained as an inappropriate response of the immune system that results in symptoms throughout the body. The symptoms one experiences are a result of defensive chemicals called inflammatory mediators that are released into tissues and circulation by the courageous and heroic white blood cells (WBCs), seemingly protecting the body from the “threatening invader” (i.e. harmless food).

While the basic process of an allergy and sensitivity is somewhat similar and both involve an over-reactive immune system, we know that allergies and sensitivities present very differently.

  • Food Allergy- IgE-mediated, Type 1 hypersensitivity
  • Food Sensitivity- non-IgE-mediated, Type 3 and 4 hypersensitivity

Oh, okay, that clears it all up!

Just kidding…

Let’s dive a bit deeper into this topic so you can feel confident giving your elevator speech the next time someone asks you to explain the difference!


Food allergy typically occurs from the mast cells (a type of WBC) of the immune system and the response is primarily led by the histamine reaction. Histamine…I’m sure you’ve heard that term before…maybe you have used anti-histamines like Benadryl to help treat an allergic response.

Food allergies affect about 6% of children and 2-4% of adults. There are many “classic” foods that generate symptoms for >90% of those people. The top 8 food allergens include wheat, soy, eggs, fish, shellfish, peanuts, tree nuts, and milk. With just 1 molecule of exposure, an allergic person may experience a response quite immediately. Common symptoms associated with food allergies include hives, itching, swelling, difficulty breathing, low blood pressure, and even anaphylactic shock.

Food Allergy Testing 

There are a few ways to help someone figure out if he/she has a food allergy, but to be honest, most people are good at figuring this out on their own. The response is very predictable and replicable. Very quickly, the allergic individual knows to stay away from that food. However, if one went to see an Allergist for testing, there are 3 main ways to identify a food allergy. There is the skin prick test, RAST test, and the gold standard medically supervised elimination diet.

After you are diagnosed with a food allergy, one must strictly avoid this food. Some children outgrow food allergies and some adults develop new allergies as they age. Check with your doctor before deciding to reintroduce (aka eat!) an allergenic food into your diet. 


Let’s switch gears and review some of the unique features of a food sensitivity. This topic is much more complex, controversial, and prevalent! At this time, there is no well-defined method to diagnose food sensitivities; therefore, there is no exact prevalence data. However, food sensitivities may impact up to 25% of the population.

In food allergy, there are the top 8 foods that impact most sufferers. On the other hand, ANY food can potentially cause a food sensitivity. Not only does that complicate things, but food sensitivities are also dose-dependent. While just 1 molecule of an allergic food may provoke a reaction, sensitivities dose response varies from person to person! Maybe 3 almonds are fine, but eating ½ cup of almond butter is no good.

Let’s complicate things even more…food sensitivities also have a delayed response time. Unlike allergies where the response is rather immediate after consumption of the food, sensitivity reactions may occur 4 to 72-hours post-consumption! Allergy responses are usually predictable and replicable, but food sensitivities produce more of the chronic type symptoms people just “accept” as their norm. Things like migraines, skin rashes, brain fog, digestive difficulties, chronic pain and inflammation, food cravings…the list goes on and on.

Food Sensitivity Testing 

As for testing, there are a wide array of panels out on the market to assess for food sensitivities. You may see tests like IgG testing, ALCAT testing, MRT testing, even muscle testing that all claim to offer the best assessment. There is not yet one validated method proven as the “best assessment” for identifying food sensitivities.

I use MRT testing for a variety of reasons (which I’ll save for an entirely new blog post) because I see amazing results in my clients. Time and time again those suffering from food sensitivities try all sorts of diets without much relief. After completing MRT testing and utilizing a specific and systemized elimination diet, clients finally achieve the health they seeking! MRT is an accurate and reliable testing method and thousands of people use it nationwide.

Below is a summary chart to help guide you through this topic.

 DescriptionCommon FoodsCommon SymptomsHow to test
Food AllergyIgE-mediated immune response, histamine reactionTop 8 food allergies: wheat, soy, eggs, fish, shellfish, peanuts, tree nuts, milkImmediate response, 1 molecule can provoke reaction: hives, itching, swelling, eczema, trouble breathing, anaphylaxisRAST test (IgE response- may determine in up to 50% of cases), skin prick test, medically supervised oral challenge
Food SensitivityType 3 or 4 hypersensitivity, immune-mediated response, >100 chemical mediators involved, challenging to diagnoseCan be any food or food chemicalDelayed reaction (4-72hrs after ingestion), dose-dependent response: GI- symptoms, migraine, pain, mood issues, eczema, etc.Elimination challenge, muscle testing, IgG test, ALCAT, /MRT


In conclusion, food allergy and food sensitivity is a challenging topic that impacts a large percentage of the population. It is vital to accurately inform yourself of key differences in order to obtain a proper diagnosis and treatment plan.

Do you suspect you have a food allergy or sensitivity? Contact me today to start a nutrition program to find relief.