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  • Writer's pictureMarissa Mekelburg MS, RDN, CLT, HHP

Food allergies, food intolerance and food sensitivities...what's the difference?

Collage picture of apples, berries, bread, salmon and radishes.

Many of us are aware of and may even know someone that has a negative reaction to food. Maybe it’s your best friend that has to avoid shellfish or a family member that avoids peanuts. In these situations, these are most likely food allergies and can be quite severe leading to hives, wheezing and even anaphylaxis.

Maybe you experience gas, bloating or diarrhea after consuming dairy – classic food intolerance.

But have you ever given thought to food causing symptoms like:

  • Headaches/Migraines

  • Joint or muscle pain/stiffness

  • Sinus congestion, pain or post nasal drip

  • Fatigue, anxiety, depression

  • Other GI symptoms such as heartburn, abdominal pain or nausea

  • Skin issues like rashes, eczema or psoriasis

These can be classic symptoms of food sensitivity.

So how do you know if you have a food allergy, intolerance or sensitivity?

While many people (including some healthcare practitioners) tend to lump allergy, sensitivity and intolerance all together there are very specific differences between all three.

Food Allergy

Also known as a Type 1 hypersensitivity reaction is the attack that is launched by IgE antibodies, which cause mast cells in your tissues to “degranulate” (break apart) and release histamine and other chemicals that cause the traditional symptoms of allergy. Reactions or symptoms typically occur within a short period of time (sometimes just minutes) of eating the offending food and can range from hives and itching to swelling of the face, tongue or lips, abdominal pain, nausea, vomiting diarrhea, dizziness, wheezing, nasal congestion or life-threatening anaphylaxis.

The top 8 Food Allergens are:

1. Peanuts

2. Shellfish (such a crab, lobster, shrimp)

3. Fish (such as bass, flounder, cod)

4. Eggs

5. Tree nuts (such as almonds, cashews, walnuts)

6. Cow’s milk

7. Soy

8. Wheat

Food Intolerance

Intolerance does not involve the immune system at all. Food intolerance is much more common than allergies or sensitivities and occur when the body lacks the correct enzyme to break down a food/food component.

An example of this would be lactose intolerance, which is very common and is caused by the body’s reduced or absent production of the enzyme lactase which is what breaks down the sugar in milk called lactose. When there isn’t enough lactase, lactose remains undigested and passes into the large intestine which creates an osmotic effect increasing fluid into the large bowel and results in pain, gas and diarrhea.

It’s also possible to be intolerant to other sugars in foods like fructose (fruit sugar) but is less common. A person can also be histamine intolerant (meaning the body is unable to break down histamine in foods) or amine intolerance (in aged foods).

Food intolerances are treated by avoiding the food that you have trouble digesting, taking digestive enzymes with meals or consuming products that already contain the necessary enzymes (like Lactaid products which are enriched with lactase).

Food Sensitivity

Food sensitivities do involve the immune system but they do NOT involve IgE antibodies and unlike allergies, sensitivity reactions are often delayed by up to 72 hours after ingestion (crazy right? I mean how is anyone supposed to determine what may be bothering them from three days ago? More on this in a bit).

There are two different types of sensitivity reactions that can occur (in a nutshell):

Type 3 hypersensitivity reaction which occurs when IgG and/or IgM antibodies (which are different than the IgE involved with true allergies) attach to offending food antigens in the bloodstream and form immune complexes. Once these immune complexes reach and attach to tissue, your immune system gets signaled that an invader is present and white blood cells go to the area and release “chemical mediators” in an attempt to destroy the immune complex. These mediators can lead to inflammation and damage in the tissue which is what leads to symptoms (because they are really meant to be fighting infection).

Type 4 Hypersensitivity doesn’t involve any antibodies but instead T cells decide that the food antigen is a threat; which stimulates the white blood cells to release the mediators previously mentioned that leads to inflammation, pain and other symptoms.

Since food sensitivities are not mediated by IgE antibodies and mast cells, traditional allergy testing will not work for identifying them.

How do food sensitivities get identified then? The most accurate way to identify food sensitivities currently is with MRT (Mediator Release Test). This blood test measures your body’s inflammatory response to food no matter what pathway triggered them (IgG, IgM, T-cells etc.) so that you can know what foods are or are not contributing to your food sensitivity symptoms.

With that being said, having the test results and not knowing how to apply them is only going to be so effective. Many times, practitioners that do some type of food sensitivity testing (whether MRT or IgG only), will typically tell you to avoid your reactive foods BUT by taking that approach, there most likely is still offending foods in your diet. There is NO way to test every food out there……

The BEST way to be tested for food sensitivities is to work with a Certified LEAP Therapist (CLT). CLT’s are certified in food sensitivities, the MRT test and the therapeutic diet using test results known as LEAP (which is what produces the best results quickly!). To find a CLT, you can search near you on Healthprofs or depending upon your states licensure and telehealth laws, you may be able to work remotely with a CLT (like me!).

Wondering if your symptoms might be related to food sensitivities?

Let's chat! Get started by scheduling an initial visit.

Picture of how food sensitivities create symptoms

Photo Courtesy of Oxford BioMedical Technologies

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