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Food allergy, sensitivity, or intolerance?

By Amy Richter, MS, RD, LD

Casein allergy. Gluten sensitivity. Lectin intolerance.

Do you ever feel lost in a sea of scary-sounding terms or headlines like these? It seems like every day there is a new term being used to describe an adverse reaction to food. You might even start to wonder if you have one (or many) of these conditions. But how do you know? Well, the first step is to understand the differences between allergies, sensitivities, and intolerances.

The terms food allergy, food sensitivity, and food intolerance are often used interchangeably and incorrectly. In reality, each of these terms means something different.

In food allergy, the body’s immune system inappropriately decides that a food is harmful and produces IgE antibodies in response (1). Whenever you eat foods that you are allergic to, you might experience some of the following symptoms: cough, wheezing, vomiting, diarrhea, itching, skin redness, or swelling of the mouth or skin (2). In rare cases, exposure to a food allergen can lead to anaphylaxis, a severe and life-threatening condition. Symptoms of food allergy usually happen very quickly (within a few minutes or hours) of consuming the food allergen. The most common food allergens are eggs, milk, peanuts, tree nuts, soy, wheat, crustacean shellfish, and fish.

The term “food sensitivity” doesn’t have a universally recognized definition. Some researchers define food sensitivity as any immune reaction to a food that does not involve IgE antibodies (3). Symptoms vary widely and can be delayed, sometimes occurring three days after eating the food. It is hypothesized that food sensitivity is one underlying cause of many chronic inflammatory conditions such as migraine, IBS, and fibromyalgia (4). One common example of a food sensitivity is non-celiac gluten sensitivity.

Food intolerances do not involve the immune system. Intolerances usually involve an inability of the body to properly digest a certain food (5). This may occur due to an enzyme deficiency, a genetic disorder, or other causes. Common symptoms of food intolerance include abdominal pain, bloating, fatigue, diarrhea, and vomiting. Symptoms often occur several hours after consuming the offending food can last for hours or even days (6). An example of a food intolerance is lactose intolerance, which happens when the body doesn’t produce enough of an enzyme called lactase that digests the lactose found in milk.

If you’re interested in learning more about food sensitivities, stay tuned for more blog posts in the future. I am currently in the process of earning a certification to test for food sensitivities. If you suffer from conditions like IBS, migraines, or fibromyalgia you might benefit from this test. You can contact me if you would like more information.

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