Food Intolerance Vs. Food Allergy
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What are Food Intolerances?

Food sensitivities or intolerances usually cause gastrointestinal (GI) upset affecting the digestive tract, but do not affect other organs in the body. Symptoms are not life-threatening and do not trigger an immune system response. Symptoms can be alleviated by either avoiding certain foods, or depending on the cause of the sensitivity, taking an enzyme to help with digestion. There are multiple causes of food sensitivities and intolerances including:

  • You may have trouble digesting certain food(s) due to lack of certain enzymes in your GI tract
  • You may have a reaction to a food additive or preservative
  • You may be sensitive to the unique sugars found in some foods
  • You may be sensitive to certain pharmacological chemicals or caffeine


The most common food intolerances/sensitivities include dairy, food additives, MSG, gluten, eggs, FODMAPs (Fermentable short-chain carbohydrates and sugar alcohols)


What are Food Allergies?

A true food allergy triggers an immune system response and can affect multiple organs in the body. When you ingest a food you are allergic to, your immune system identifies a protein in the food as a threat and creates antibodies as a defense. These antibodies cause organs in the body such as the lungs, skin, nose, throat, eyes, or GI tract, to release histamines which cause signs and symptoms of an allergic response. Depending on the severity of your body’s allergic reaction, you may be able to take an anti-histamine to reduce the symptoms, or you may require a shot of epinephrine and medical attention if you have an anaphylactic, life-threatening reaction.

Anaphylaxis is the most serious allergic response and can cause rapid onset of life-threatening symptoms including shortness of breath, swelling of the tongue and throat, low blood pressure, vomiting, rash, and lightheadedness.  Anaphylaxis typically occurs when the immune system overreacts to an insect bite, a medication, or ingestion of an allergen containing food.


The 11 most common food allergens in Canada include milk, eggs, wheat, soy, peanuts, tree nuts, shellfish, mustard, sulphites, seeds, and fish.


Signs & Symptoms

                                Food Intolerance                         

Food Allergies

Diarrhea or Constipation








Stomach Cramping/Pain

Anaphylaxis – wheezing, difficulty breathing, dizziness, death


Drop in Blood Pressure


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