Food Allergy vs. Sensitivity: What's the Difference?

Overview

What’s the difference between being allergic to a food and being sensitive or intolerant to it?

The difference between a food allergy and sensitivity is the body’s response. When you have a food allergy, your immune system causes the reaction. If you have a food sensitivity or intolerance, the reaction is triggered by the digestive system.

Symptoms of food intolerance include gas, bloating, diarrhea, constipation, cramping, and nausea.
Symptoms of food allergy include hives, swelling, itching, anaphylaxis, and dizziness.

Food sensitivities

Sherry Farzan, MD, allergist and immunologist with North Shore-LIJ Health System in Great Neck, N.Y., says that that food sensitivities are not life-threatening. She explains that there are food intolerances that are not immune-mediated. Instead they’re caused by an inability to process or digest a food.

Food sensitivities and intolerances are more common than food allergies, according to the British Allergy Foundation. Neither involves the immune system.

A food triggers an intolerance in your digestive tract. This is where your body can’t properly break it down, or your body reacts to a food you’re sensitive to. For example, lactose intolerance is when your body can’t break down lactose, a sugar found in dairy products.

You may be sensitive or intolerant to a food for a few reasons. These include:

not having the right enzymes you need to digest a certain food
reactions to food additives or preservatives like sulfites, MSG, or artificial colors
pharmacological factors, like sensitivity to caffeine or other chemicals
sensitivity to the sugars naturally found in certain foods like onions, broccoli, or Brussels sprouts

Symptoms of food sensitivity vary. But the symptoms of intolerance are all digestive-related. These can include: