What to Know About Food Allergies, Intolerances, & Sensitivities

In recent years, discussion about food allergies, intolerances, and sensitivities have been on the rise. It can seem confusing and overwhelming, especially if you’re one of the millions of Americans experiencing unpleasant symptoms after eating certain foods. In this article, we’re going to debunk the confusion and define the difference between food allergies, intolerances, and sensitivities, and what to do if you suspect you have one!

What is the difference between food allergies, intolerances, and sensitivities?

Food allergies result in an unpleasant or dangerous immune system reaction after a certain food is consumed. The body mistakenly treats proteins found in this food as a threat, resulting in the release of a number of chemicals. It's these chemicals that cause the symptoms of an allergic reaction. Antihistamine drugs can treat mild reactions, but more severe reactions need the drug epinephrine injected to prevent life-threatening complications. It is currently estimated that 32 million Americans have a food allergy.

Food intolerances refer to the inability to process or digest certain foods. There are many types, but you’ve probably heard of lactose and gluten intolerance in the media. Most of the time with food intolerances the body lacks certain digestive enzymes that help break down food, causing unwanted digestive issues.

Food sensitivities are still being studied, but it is believed by some experts that exposure to specific foods may create an immune and inflammatory reaction. These symptoms can include joint pain, stomach issues, fatigue, rashes, or brain fog. 

What specific foods cause issues?

The eight most common food allergies include milk, eggs, peanuts, tree nuts, wheat, soy, fish, and crustacean shellfish. If you have a food allergy, you generally know within a few minutes to two hours after eating the food. If you feel tingling or itching in the mouth, hives, or difficulty breathing, you are probably having an allergic reaction that needs to be addressed ASAP.

The most common food intolerances include gluten, lactose, casein, eggs, soy, fish, and nuts. With food intolerances, you generally experience gastrointestinal discomfort within 30 minutes after consumption, but in some circumstances symptoms may not occur for up to 48 hours. Symptoms include nausea, bloating, abdominal pain, and diarrhea. 

Food sensitivities are still being studied, but some of the most commonly reported foods include gluten, dairy, eggs, and pro-inflammatory foods such as high fat or sugar foods. Symptoms are similar to sensitivities in that they can occur right away or within a few days after consumption.

What should I do if I think I have a food allergy, intolerance, or sensitivity?

Start working with your doctor and registered dietitian right away. Especially if you think you have a food allergy, because they can be life-threatening. Even though food sensitivities and intolerances don’t generally display life-threatening results, they can cause issues with nutrient absorption, inflammation, low energy, fatigue, and other unpleasant symptoms that can worsen down the road.

To test for food allergies,  a physician can diagnose you after analyzing your symptoms, family history, and may consider a skin or blood test. You can also test for food allergies using an oral food challenge, where under the supervision of your doctor you are given small but increasing amounts of food suspected to cause symptoms. If you have a reaction, it’s likely a food allergy. 

In terms of food intolerances and sensitivities, testing is normally done through a basic elimination diet. There are some food sensitivity tests available, but the accuracy of these tests aren’t determined at this time. The cheapest and most informative way to determine if you have a food sensitivity or intolerance is to do an elimination diet under the supervision of your registered dietitian!

The most important thing you can do to set yourself up for success is to meet with your doctor and registered dietitian to guide you through the process. Blindly following elimination diets may put you at risk for developing nutrient deficiencies and unintended weight or muscle loss. Plus, the process can be extremely overwhelming, so having support along the way will make it an easier transition!