Allergies vs. intolerances

One friend says he has a food sensitivity, another says she has a food allergy. What is the difference and what do they mean? If you or someone you care about has problems with certain types of food, there can be a lot to learn. Here are the basics to help you get started.

Food sensitivity is an umbrella term used to describe any adverse reaction to food that you might experience. This means adverse reactions such as hives, wheezing, or wanting to gag at the thought of brussel sprouts. "Food sensitivities" refers to both food allergies and food intolerances. So what is the difference between an allergy and an intolerance, you ask? The answer lies in the immune system.

A food allergy occurs when your immune system reacts to a certain food as though it were harmful and something to be fought off. The first time the person with a food allergy encounters their trigger (or allergen), their bodies invoke a defence mechanism and create antibodies (specialized proteins) called immunoglobulin E (IgE). When the allergen is next introduced, the body releases these IgE antibodies as well as other chemicals (histamine being one) to defend itself against the perceived threat – and thus an allergic reaction proceeds. The symptoms of the reaction can vary in degree of seriousness from hives and tingling in the mouth to wheezing to a life-threatening encounter with anaphylaxis, a severe form of allergic reaction.

Comfortingly, actual food allergies are relatively rare – in Canada, only 3% to 4% of adults and 6% of children live with these conditions. As the numbers indicate, children tend to outgrow allergies. However, there's no guarantee, especially if the allergy involves peanuts, shrimp, or fish. And unfortunately for adults, there's no moment at which you receive your free pass, as allergies can develop at any age.

Food intolerance is a bad reaction to food that does not involve the immune system. Its root often lies in the gastrointestinal system, and is related to an individual's inability to digest or absorb particular foods (or parts thereof). Because the immune system is not at work here, it generally takes a larger, more portion-sized amount of the problem food to trigger a reaction, as opposed to the tiny amount that is often enough to trigger an allergic response. Symptoms of food intolerance can include gas, bloating, vomiting, and diarrhea. A well-known type of food intolerance is lactose intolerance, which is an inability to digest lactose, the sugar in milk.

All material copyright MediResource Inc. 1996 – 2021. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: