Food Allergy Vs. Food Intolerance

Gather round, boys and girls. We're going to make you aware of something you probably don't know much about unless you're part of the 1 percent. No, not that 1 percent — the 1 percent of adults with food allergies. See, you already learned a statistic that at the very least can make you sound smart in some future conversation. Yay, awareness!

You've probably heard of lactose intolerance and celiac disease. And you might know someone who avoids peanuts, shellfish, or some other food like the plague due to an allergy. But what's the difference between food intolerance and a food allergy anyway?

Food allergies
It might seem like your friend with a food allergy unnecessarily interrogates waiters over their menu items, but they have good reason to do so. Even a small amount of the offending food can cause a severe reaction within minutes — even seconds. Symptoms can include rash or hives, nausea, cramping, stomach pain, diarrhea, itchy skin, shortness of breath, or chest pain; but even more dangerous reactions can follow consumption, including anaphylaxis, which results in breathing problems and dangerously low blood pressure.

The most common triggers of food allergies, according to the American Academy of Dermatology, are milk, eggs, peanuts, tree nuts, and shellfish. When a person with a food allergy ingests that particular food, their body mistakes an ingredient in that food for a harmful intruder and launches a full-out attack on it via our immune system's antibodies. The physical reaction people experience is the result of that attack.

The only way to prevent the reaction is to avoid the food entirely. If the person accidentally ingests it, it's possible they will need immediate medical attention or the administration of epinephrine (aka adrenaline) through a prescribed medication like an EpiPen to suppress the reaction.

Skin pricks or blood tests are usually used to diagnose food allergies. Skin pricks tend to be cheaper and can be taken care of in a physician's office. Unfortunately, it is possible to develop food allergies as an adult even if you've never had adverse reactions to foods before. Check out our story on it to learn more.

Food intolerance
While a food allergy can have life-threatening consequences, food intolerance mainly causes uncomfortable but not severe symptoms. Food allergy reactions affect the immune system, but food intolerance reactions mess with our gastrointestinal system, often causing nausea, stomach pain, gas/cramps/bloating, vomiting, heartburn, diarrhea, headaches, and irritability or nervousness, according to the Cleveland Clinic.

Allergic reactions to food can hit a person immediately after eating; food intolerance symptoms, on the other hand, usually take effect gradually. Food intolerance is much more common than food allergies, with lactose intolerance alone affecting 10 percent of Americans. People with food intolerance can usually consume small amounts of the food without getting sick, and preventive over-the-counter pills like Lactaid can help people eat a little ice cream without having to sprint to the bathroom 30 minutes later.

Potential causes of food intolerance include lacking an enzyme necessary for digestion of the particular food (as is the case with lactose intolerance), irritable bowel syndrome, sensitivity to food additives such as the sulfites in dried fruits and wine, and celiac disease. People with celiac disease are unable to eat gluten, a protein found in wheat and other grains, without experiencing digestive problems shortly afterward. While this intolerance does affect the immune system, it does not have the potential to cause anaphylaxis.

The best way to determine whether or not you have a food intolerance is trial and error; try eliminating the potentially offending food from your diet, and see if your digestive problems disappear.

More resources
The Food Allergy & Anaphylaxis Network has some helpful educational material for both adults and children on its website: FoodAllergy.org.

— Melissa Valliant, HellaWella

More From HellaWella:

• Can you develop food allergies as an adult? Unfortunately, yes.

• Fiber facts: Why it's essential for weight loss and health