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

Various foods know to cause allergic reactions laid out on a white background.

Although many people use the terms intolerance and allergy interchangeably, there’s a significant difference between the two. Here’s what you need to know.

What Causes Food Allergies?

When you have a food allergy, your immune system is reacting to one or more proteins it sees as a threat. This triggers a full-body response that affects multiple organs and causes a variety of symptoms. Swelling, itching, hives, vomiting, and diarrhea are all common reactions to a food you’re allergic to.

Sometimes, the symptoms can even be life-threatening. This is particularly true in cases of anaphylaxis, which can cause difficulty breathing and a sudden drop in blood pressure.

The following eight culprits trigger 90 percent of all food allergies: tree nuts, peanuts, shellfish, fish, milk, eggs, soy, and wheat.

While some people have an immediate, intense reaction that requires medical attention—such as the administration of epinephrine to halt an anaphylactic reaction—not all food allergies generate an obvious response. The tricky thing about a food allergy is the body’s response to it can sometimes be delayed. This makes it hard for some people to identify what is causing their discomfort.

The symptoms often occur in the digestive tract, and they can include acid reflux, vomiting, bloating, or diarrhea. Recent studies have also found that a large number of eczema cases in young children were triggered by a food allergy.

With such a wide variety of symptoms and the potential of a delayed reaction, it’s not surprising some people fail to accurately identify their condition or diagnose themselves correctly.

What Causes a Food Intolerance?

A food intolerance is similar to an allergy, but less severe. This is because an intolerance doesn’t involve a reaction from the immune system. It’s usually the digestive tract that’s most affected by offending food.

Although they’re more dangerous, food allergies are simpler to explain—your body thinks a protein doesn’t belong there and has a negative reaction to it.

Food intolerances, however, have more complex triggers. They can involve more components than a simple immune response. The symptoms can also be understated and, occasionally, delayed. However, signs of an intolerance usually involve bloating, wind, nausea, cramping, diarrhea, or constipation.

Many things can cause you to have a sensitivity to certain foods. The following are some of the most common reasons people develop a food intolerance:

  • They lack a particular enzyme: For example, people who are lactose intolerant don’t have lactase, the enzyme that breaks down the sugar found in dairy products.
  • Sensitivity to additives and preservatives: The sulfites in red wine and canned foods, MSG, or food coloring are just a few examples that can cause an intolerance.
  • Irritable bowel syndrome (IBS): This chronic condition causes people to be intolerant of many foods, including certain naturally occurring sugars.

If you experience a specific symptom we covered above on a regular basis, consult your physician. Describe what you’re experiencing and see if he or she can identify whether you have a food allergy or intolerance. This is especially important if you have an allergy because you might be at risk of anaphylaxis.

Your doctor can provide you with all the information you need to recognize and manage a food allergy. It’s also important that you understand when you need to skip self-treatment and seek medical attention.

You can mitigate the symptoms of a food intolerance with an appropriate diet and, when applicable, enzyme supplements to help you digest the desired food. Nevertheless, it’s always best to try and prevent any form of discomfort.

If you have a food allergy or intolerance, make sure you always read food labels before making a purchase. Also, be sure to discuss the contents of your meal at restaurants to ensure it will be safe and won’t cause you any discomfort later.

Carla Cometto Carla Cometto
Carla has been writing professionally for five years and blogging for many more. She's worked as a journalist, photographer, and translator. She's also an avid traveler who hopes to inspire a sense of curiosity and adventure in others through her writing. Read Full Bio »
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