What’s the Difference Between a Food Allergy and a Food Intolerance?

What’s the Difference Between a Food Allergy and a Food Intolerance?

While some symptoms of food intolerance and food allergy are similar, the differences between the two are very important. If you have a food intolerance, eating that food can leave you feeling miserable. However, if you have a true food allergy, your body’s reaction to this food could be life-threatening.

Digestive System Versus Immune System
A food intolerance response takes place in the digestive system. It occurs when you are unable to properly breakdown the food. This could be due to enzyme deficiencies, sensitivity to food additives or reactions to naturally-occurring chemicals in foods. Often, people can eat small amounts of the food without causing problems.

A food allergic reaction involves the immune system. Your immune system controls how your body defends itself. For instance, if you have an allergy to cow’s milk, your immune system identifies cow’s milk as an invader or allergen. Your immune system overreacts by releasing chemicals that cause an allergic reaction. Symptoms of allergic reactions to food are generally seen on the skin (hives, itchiness, swelling of the skin) along with gastrointestinal symptoms (vomiting and diarrhea) or respiratory symptoms. Generally, respiratory and gastrointestinal symptoms do not occur alone.

Unlike an intolerance to food, a food allergy can cause a serious or even life-threatening reaction by eating a microscopic amount, touching or inhaling the food.

How to Test for Food Allergies Versus Food Intolerances
Skin testing evaluates for food allergy reactions through your immune system. Skin testing cannot be used to evaluate for food intolerances.

The best way to determine if you are intolerant to a food is to keep a food diary. If you are suspicious that you are intolerant to a food, avoid that food for two weeks to see if symptoms resolve. Then, reintroduce the food to see if symptoms worsen. If symptoms worsen, you are likely intolerant to that food.

To the Point
There is a very serious difference between food allergies and being intolerant to a food. If you think you may benefit from allergy testing, please call the Allergy & Immunology Clinic at 425.690.3486 or visit the clinic website.

Adapted from American Academy of Allergy, Asthma & Immunology

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