What makes a food allergy?

Food Allergies

What is a food allergy exactly? How do I know if it’s an allergy or an intolerance?

These are questions many Americans ask themselves daily. Believe it or not, anyone can have an allergic reaction to anything at anytime. Crazy, huh? That is why it is imperative that everyone understands what a food allergy is and is not.


A food allergy is when the body’s immune system negatively responds to a food every time you eat it. Some reactions are uncomfortable or unsightly, but many can be dangerous and even potentially life threatening. The reaction occurs immediately upon being exposed to the food. A food intolerance occurs within hours of consuming the food and is generally a digestive response only.

The most common food allergies

Currently the most common food allergies are milk, eggs, peanuts, tree nuts, fish, shellfish, soy, wheat and sesame with milk at the top of the list as an allergy and intolerance. Milk/dairy is so prevalent in our food supply it’s hard to avoid but, if you have an allergy, avoidance is key.


When someone has a dairy allergy for example and they ingest milk it is as if the body immediately goes to war. Even trace amounts of dairy or any allergen can trigger an allergic reaction. Reactions can include symptoms such as hives, wheezing, difficulty swallowing, vomiting, confusion and much more. Anaphylaxis, the most serious type of an allergic reaction, generally involves multiple organs and comes about fast and furious. What makes anaphylaxis so frightening is it often affects the persons’ breathing or blood circulation, both of which could have life threatening consequences.


Food intolerance

On the other hand, one may have a food intolerance to dairy if they only experience unpleasant GI symptoms such as gas, bloating, nausea, reflux, etc after consuming it. Unlike an allergy, an intolerance is often correlated to dosage of the food. Many people who have a dairy intolerance can handle a small amount of dairy and be unaffected; however, if they consume significant amounts of the food they will begin to feel unwell.


While some people may use food intolerance and food allergy interchangeably you can see the two diagnoses are actually quite different. If you have experienced an allergic reaction; a distressing, immediate, immune system response, similar to as previously stated you should seek out an allergist to determine if you have a true food allergy. If your symptoms involve only the GI tract then seeing an allergist is not necessary. Instead try eliminating the food from your diet for 2-4 weeks and track your symptoms. Once that timeframe is complete, reintroduce the food and compare how you feel against when the food was eliminated from your diet. This clinical information will inform your diagnosis.


Ultimately only an Allergist can diagnose a food allergy based on your clinical history and testing.