Food Allergies, Sensitivities and Intolerances… What’s the Difference?

What’s the Difference Between Food Allergies, Sensitivities & Intolerances?

Dr. Kimberley O'BrienBlog, Food, Health Leave a Comment

As a naturopathic doctor, I help my patients to identify and address the root cause of their symptoms including fatigue, bloating, sinus congestion, digestive upset, joint pain, headaches, acne, and eczema. Did you know that all of these symptoms can be caused directly by various reactions to specific foods?

Today I’m walking you through the five types of adverse food reactions that may be leading to your chronic symptoms and low energy. These reactions include food allergies, food sensitivities, celiac disease, chemical sensitivities, and food intolerances. By identifying whether you have any specific food triggers, you’ll be better equipped to fuel your body for health and energy instead of sickness and fatigue!

What’s the Difference Between Food Allergies, Sensitivities and Intolerances?

Food Allergies

Food Allergies

When discussing adverse food reactions, food allergies are what people tend to be most familiar with.  I’m sure we all know someone who experiences these reactions to peanuts, shellfish or other foods and know the potential severity of this reaction.  However, in order to understand other types of food reactions, it’s very helpful to first review specifically what occurs in people with food allergies!

Cause and Symptoms of Food Allergies

A food allergy occurs when your body experiences a quick and often severe immune response to a particular food.   In people with food allergies, exposure to a specific food triggers their body to produce antibodies against the proteins within that food.  For those of you wanting all of the science-based details, the type of antibodies produced with food allergies is what’s referred to as a fast acting “IgE” antibodies.   This becomes an important detail when we later compare food allergies to food sensitivities.

Antibodies are like sticky pieces of velcro that circulate in your body and stick on to proteins that your immune system has perceived as a potential threat.  The job of these antibodies is to “tag” these proteins in order to allow other immune cells to find them and “clean them up”.  This antibody-based “tagging” of these specific food proteins causes other immune cells to release chemicals like histamine, which may produce symptoms including itching, swelling, hives, nausea, vomiting, diarrhea or anaphylaxis after consumption of that food. 

Unlike food sensitivities, which we will discuss next, the immune reaction that occurs with food allergies takes place very quickly.  Symptoms of food allergies typically become apparent immediately or within 30-minutes of exposure to that food.  The severity of the symptoms experienced, combined with their rapid onset, generally makes it straightforward for people to identify that they have food allergies as well as the foods to which they are allergic to.

Most Common Food Allergens

Due to the quick onset and severity of symptoms that may be experienced with food allergies, most people are very aware that they have allergies and also know which food(s) are their immune triggers.  Allergic reactions have been reported to over 170 different foods but the most common food allergens include peanuts, tree nuts, egg, wheat, milk, fish, shellfish and soy.  Food allergies are most common in children but may also develop later in life or may persist into adulthood.

How to Test for Food Allergies

The IgE antibodies that are produced during an allergic response are quickly degraded, which makes it difficult for these antibodies to be evaluated via blood testing unless it’s completed very soon after you experience an allergic response.  Therefore, testing for food allergies is typically done via a skin-prick allergy test in which the particular food is introduced directly onto your skin.   The doctor or allergist will then monitor for an immune response (itching, redness, and hives) within the 30-minutes that follows.  If you experience localized redness, itching or hives, this is considered a positive reaction indicating that you are allergic to that food.

Treatment of Food Allergies

Food allergies are managed by avoidance of that particular ingredient or food trigger. It’s important for anyone experiencing food allergies to carry an EpiPen with them, especially if their symptoms include swelling of their mouth or if they have experienced a previous anaphylactic reaction. It can also be helpful to consult with a naturopathic doctor if you experience multiple food allergies, as it’s also important to investigate the root cause as to why your immune system has become over-reactive.

Food Sensitivities

Food Sensitivities

Food sensitivities are very different from food allergies and they produce a different type of immune response.  The reaction produced with food sensitivities is more gradual and the symptoms can be more diverse, which unfortunately means that people are often unsuspecting of specific food triggers as a root cause of their chronic symptoms.  Identifying that I have food sensitivities enabled me to resolve my acne, eczema, bloating, fatigue and brain fog and it’s now an important part of the work that I do with each of my patients.


Cause and Symptoms of Food Sensitivities

Like food allergies, food sensitivities involve your body mounting an immune response against specific food proteins.  However, the antibodies produced are a different sub-type called “IgG antibodies” and they lead to a slower, more systemic immune response.   Therefore, the symptoms produced by these reactions can take as long as 72 hours (3 days!) to reach a peak!  Regular consumption of these foods leads to a cumulative immune response and causes you to chronically feel unwell.  For this reason it’s entirely possible that you may be consuming foods you are sensitive daily without even suspecting them to be at the root cause of your chronic symptoms!

The symptoms of food sensitivities tend to be chronic in nature, which is very different from the prominent and acute symptoms experienced with food allergies.  These symptoms of food sensitivities can include fatigue, bloating, digestive upset or irritable bowel syndrome (IBS), chronic sinus congestion or cough, eczema, acne, joint pain, headaches and more.  Last week I shared 10 signs that you may be experiencing food sensitivities, and I encourage you to also read that here.

Most common food sensitivities

As with food allergies, food sensitivities can result from a number of different food triggers. The most common food sensitivities include but are not limited to:

  • Wheat and other gluten-containing grains
  • Dairy products (milk, cheese, yogurt, whey protein)
  • Eggs
  • Corn
  • Soy
  • Tree nuts (almonds, cashews, hazelnuts, etc…)
  • Legumes (beans, lentils, peas)
  • Citrus fruits (oranges, lemons, lime)  

These reactions are common but highly individualized, and a food that may be healthy for your friend may be the exact food that has been dragging you down!

How to Test for Food Sensitivities

Food sensitivity testing can be completed via a blood test that assesses for elevated levels of IgG antibodies to various foods. I utilize food sensitivity testing for my patients quite often and I find the results to be very clinically significant.  It often takes only several days to a few weeks for my patients to experience symptomatic improvement upon avoiding the foods that were identified as reactive on their food sensitivity report.

Another way to identify your food sensitivities is via an Elimination Diet, which is my favourite method of identification because it’s also an amazing way to boost your energy,  lose weight and improve your overall health.  Additionally, an Elimination Diet also enables you to identify other types of food reactions like chemical sensitivities or food intolerances, which I describe later in this article.  I have a free eBook, “A Naturopathic Guide to Identifying your Food Sensitivities” that explains in detail how to complete an Elimination Diet and you can download it for free here.

Treatment of Food Sensitivities

Once you have identified your food triggers, they should be avoided as much as possible for at least the first 6-8 weeks. This initial avoidance allows any active immune response to subside. After this period of avoidance, many people find that they are able to tolerate these reactive foods in moderation. Tolerance of these foods becomes more likely if you have also been supporting your overall digestive health, and working with a naturopathic doctor is very helpful in that regard!

Celiac Disease

Celiac Disease

It’s important to differentiate that celiac disease is an autoimmune condition that is triggered by gluten and that it’s very different from a gluten-sensitivity.  If you have suspicions about gluten as a cause for your symptoms it’s important to screen for celiac disease prior to beginning a gluten-free diet. This can be done via a simple blood test for antibodies against “tissue transglutaminase”, which can be requested through either your naturopathic doctor or family doctor.  Gluten-avoidance can lead to a false-negative test result, which is why it’s so important to test prior to making any dietary modifications.  This is especially if you have a family history of celiac or other autoimmune diseases.

Chemical Sensitivities

Chemical Sensitivities

There are certain foods that contain chemicals that can be directly irritating to your body. In the majority of people these chemicals do not trigger any concerns, but in susceptible individuals these chemicals can produce inflammation, pain, and irritation. This can include chemicals that have been added to foods like pesticides, monosodium glutamate (MSG) or synthetic colourings, but it can also include natural chemicals such as salicylates, histamine, and alkaloids.  

For example, alkaloids are a type of chemical that are found naturally in the nightshade vegetable family, which includes potatoes, tomatoes, peppers, and eggplant. While the majority of people can tolerate this chemical without concern, in certain people it can lead to symptoms including headaches, migraines, joint pain, skin rashes, and irritable bowel symptoms.

Chemical sensitivities are typically best managed by avoiding the ingredients that cause your symptoms, and working with a naturopathic doctor is always important to help you to identify and treat the root cause of your specific concerns.

Food Intolerances

Food Intolerances

Food intolerances are different from food allergies and food sensitivities in that they are not an immune-based response. Instead, food intolerances occur when your body is unable to adequately digest a particular ingredient. The most common example of this is a lactose-intolerance, as described below.

Lactose is a sugar that’s found in dairy products like milk, cream, yogurt, and ice cream. In order for lactose to be absorbed from our digestive tract, the small intestine must first break it down by releasing an enzyme called “lactase”. Unfortunately, it’s estimated that 65% of the population has a reduced ability to break down lactose after two years of age, meaning that your body may not able to digest all of the lactose sugar in dairy products.

Consuming foods that are high in lactose can cause cramping, gas, bloating and/or diarrhea soon after eating from the buildup of these indigestible sugars in your colon. People with lactose intolerance may be able to tolerate milk and other lactose-containing dairy products with the help of digestive enzymes containing lactase to break down the sugars.  They may also choose to only consume lactose-free milk and dairy products.

It’s very important to note that if you have a dairy-sensitivity in addition to a lactose intolerance, your immune system will still react to the milk, casein and/or whey proteins that are present even in lactose-free dairy products.  Completing an Elimination Diet will help you to gain more clarity as to the cause of your symptoms while also enabling you to identify your specific food triggers.

How to Identify your Food Allergies, Sensitivities and Intolerances with an Elimination Diet

The most comprehensive way to identify if your symptoms are caused by food allergies, sensitivities or intolerances is to complete an Elimination Diet. My eBook, “A Naturopathic Guide to Identifying your Food Sensitivities”, teaches you the step-by-step process that I use with my patients to help them identify their food triggers and it’s available to you (for free!) here.  I also have an online program called the Elimination Diet Meal Plan, which includes over 70 delicious recipes, regular and vegan meal plans , weekly grocery lists, ingredient guides, symptom tracking forms, weekly motivational emails and more.  It’s the exact program that I utilize with my one-on-one patients (with rave reviews) and you can also now access it online here.

How to do an elimination diet

Have you identified the specific foods or ingredients that are causing your own health concerns? Let me know in the comments below!

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Did you know that food sensitivities cause symptoms like fatigue, bloating or IBS, weight-gain and skin concerns?

Free Guide to Identify Food Sensitivities

Discover which foods are the cause of your symptoms with my FREE GUIDE -  A Naturopathic Guide To Identifying Your Food Sensitivities!

Food Allergies, Sensitivities and Intolerances… What’s the Difference?

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