Food Allergies, Intolerances and Sensitivities. What are the differences?


The identification of a food allergy versus a food intolerance or a food sensitivity could be problematic and they are frequently confused. Food allergies, food intolerances, and food sensitivities can have some similarities, but there are clear differences in the origin between these conditions. Do you know what are the differences?


Food allergies consist of the immune system response (IgE) to a certain food. The body senses that a protein in a particular food may be harmful and triggers an immune system response, producing histamine to protect itself. Histamine causes allergy symptoms such as hives, coughing, and wheezing. The body then "remembers" this immunologic reaction and when the allergen food enters the body again, the histamine response is more easily triggered. Food allergies can show up at any time in our lives, even during older adulthood.

Symptoms of an Allergic Reaction 

Food allergy symptoms typically appear within a few minutes to two hours after consumption of the allergen. Allergic reactions can include:

  • Hives, flushed skin, or rash
  • Tingling or itchy sensation in the mouth
  • Swelling of the tongue, lip, throat, or face
  • Difficulty breathing
  • Vomiting
  • Diarrhea
  • Abdominal cramps
  • Coughing or wheezing
  • Dizziness or lightheadedness
  • Loss of consciousness

If you suspect you have a food allergy, go to your health care provider and ask for an allergy test. And if you have a diagnosed food allergy, consider always reading scrupulously ingredient labels and carrying epinephrine shots in case of accidental ingestion or contact with the food.


Food intolerances are our body's digestive system's response to a certain food. Unlike a food allergy, which produces an immunological mechanism after consuming an allergen, a food intolerance produces a non-immunological reaction. Food intolerance refers mostly to the inability to process or digest certain foods due to the lack of enzymes being created in the stomach. One example of the most common food intolerance is lactose intolerance. The body of an individual experiencing lactose intolerance does not have the enzyme lactase to help aid the body into the digestion of dairy products, therefore it will develop different symptoms after consuming dairy products.

Symptoms of food intolerance

Food intolerance symptoms can appear from 30 minutes to 48 hours after the problematic food is ingested. Some of the most common symptoms include:

  • Gas/Bloating
  • Diarrhea/Constipation
  • Cramps
  • Headaches/Migraines
  • Feeling tired, lethargic
  • Brain fog
  • Skin reactions and conditions (hives, acne, eczema)
  • Joint pain
  • Sinus congestion

Some individuals with food intolerance can tolerate a certain quantity of food in small amounts. However, avoiding the food that causes intolerance is the best way to avoid symptoms completely, and end the problem for good. Over-the-counter enzyme supplements can also help, but they are not crated for daily use. 


After eating certain foods some people develop symptoms that are not related to food intolerances or food allergies. These are referred to as food sensitivities. Though there is controversy around what exactly happens in the body of someone with food sensitivity, it appears that exposure to specific foods may create an immune reaction (IgG) that generates different symptoms.  Therefore, we can describe a food sensitivity as a delayed immune reaction to a specific food that may cause disruptive symptoms in the body. Gluten is probably the best-known trigger of food sensitivities.

Symptoms of a food sensitivity

Food sensitivity symptoms can appear within hours to several days after the problematic food is ingested, and many times the effects are accumulative. Some of the most common symptoms are:

  • Fatigue
  • Difficulty concentrating 
  • Joint pain 
  • Headaches or migraines 
  • Stomach pain 
  • Gas/Bloating/Fermentation
  • Diarrhea/Constipation
  • Rashes
  • Brain fog

The best tool we have to identify food sensitivity is a process of careful observation and experimentation. Removing the foods believed to cause reactions from the diet for two to four weeks, reintroducing them one by one, and watching for symptoms. This is called an elimination diet.

Food sensitivities, can also, fade away with time. Our bodies, immune systems, and the gut microbiome are continually changing, that is why at some point, you may consider trying to reintroducing small amounts of the food that you have been sensitive to, to see if you remain reacting to it.

The dangers of food allergies, intolerances, and sensitivities

When you struggle with an ongoing, unidentified food allergy, intolerance, or sensitivity, your body constantly sends out inflammatory responses that can cause harm in multiple ways. These conditions are correlated with an increased chance of developing chronic fatigue, arthritis, nutrient deficiencies, skin conditions, autoimmune disorders, insomnia, weight gain, migraines, and irritable bowel syndrome. If you suspect that you may have one of these conditions, book an appointment with your doctor to get the proper testing and rule out any potentially dangerous conditions (like autoimmune conditions such as celiac disease) and speak to a health expert about going on a monitored elimination diet.

Let me help you to create a nutritional and lifestyle plan to achieve your health goals.