Food Allergies, Sensitivities, and Intolerances – What’s the Difference?

Are You Reacting to the Foods You Eat?

Many times in my practice, patients will ask me – “What is a food allergy?” Or “What is a food sensitivity?” and “Is that the same as a food intolerance? What are the differences?” This confusion only makes sense, as some reactions to foods are very noticeable while others are more subtle. If you’ve been feeling unwell and suspect that food allergies have something to do with it, then read on. I’ll break down the differences between allergies, sensitivities, and intolerances, focusing mainly on food intolerances. I’ll give you the top 10 food offenders I see in my practice, along with steps to take to determine what foods are good for your body, rather than inflammatory.

What Are Allergies, Anyways?

Let’s start at the beginning. The word “allergy” is derived from the Greek word meaning “altered reaction”. This reaction can range from having a headache to nausea, vomiting, hives, migraines, asthma etc. whenever you are exposed to a problematic substance. However, some patients can have no overt symptoms at all, but suffer a general malaise possibly due to an internal inflammatory reaction. This substance which provokes a reaction is called an allergen. There are many allergens in the world; the most famous ones being house dust, dog danger, tree pollen, just to name a few. More often than not, a patient can have “hidden” food allergies, and these are known as IgG food sensitivities.

The Difference Between a Food Allergy, Sensitivity and Intolerance

According to the Health Canada website, there are slight differences between food sensitivities, food intolerances and food allergies. Let’s talk about them in more detail.

Food sensitivities are typically an adverse reaction to foods that other people can eat with no concerns. Food intolerances, on the other hand, can show symptoms only after a particular amount of that food has been ingested. In contrast, a food allergy is seen when the food proteins are recognized by the immune system as being harmful like a virus or bacteria. In my practice, I see dairy, eggs, gluten, pineapple and kidney beans as being the most common offenders.


For most people, the term “allergy” creates images of itchy eyes, runny noses, congested sinuses etc. However, an allergy can affect any organ system, such as the digestive tract or the skin or the joints. Irrespective of how they show up, allergies are very common. Allergies can start or end at any point in life. It is common for patients to grow out of allergies or develop allergies throughout life, as well.

Having allergies impacts a person’s ADL’s or activities of daily living, and it causes low work productivity. An example of a serious food allergy would be celiac disease, whereby a person has an allergy to a molecule found in some foods, called Gluten or Gliadin. Depending on the severity of this disease, associated costs could be specific medications and surgery.


Food sensitivities are adverse reactions to a food that other people can eat safely – it is the umbrella for all food and food-based ingredients that can elicit a reaction in the body. Traditionally, a food sensitivity has not been seen as a type of allergy per se.

On the other end of the spectrum, a food allergy has a classic immune response with numerous IgE immediate hypersensitivity antibodies to a specific food protein being released. In these cases, the immune system thinks that the food protein is similar to a harmful pathogen, such as a bacteria or virus, and mounts an immediate immune response. With repetitive exposure, the immune system produces large quantities of histamine which adversely affect the lungs, heart, skin and gastrointestinal tract. If the histamine release exceeds a certain point, the person could suffer a fatal anaphylactic reaction.


In the middle, between the food sensitivities and food allergies, there are food intolerances, wherein a larger amount of food has to be consumed in order to produce symptoms. The most common example of this would be lactose intolerance, where the enzyme lactase is deficient. When taken in smaller quantities, most people with this intolerance can handle the lactose, especially when the lactose is combined with other foods. However, when larger quantities are consumed, a person will suffer from abdominal pain, diarrhea, flatulence, and bloating.

Food intolerances can be considered a milder form of an allergy, even though there is no immediate allergic response like the classic food allergy – they tend to be delayed. In fact, studies show that food intolerances involve other types of antibodies like IgM, IgA, IgD and IgG. Since IgG antibodies are produced at a slower rate, often hours to days after exposure (as compared to IgE immediate hypersensitivity antibodies created in minutes) food intolerances have not historically been considered an allergy.

Delayed food reactions can occur up to several days after ingestion of the reactive food, making it difficult to link up one’s symptom to the food eaten several days prior. Such hidden intolerances are often the cause of many chronic inflammatory symptoms. These antibodies combine with the food particles in the blood to form immune complexes, which in turn, create inflammatory reactions in tissues. Such inflammatory reactions can affect any part of the body, and produce symptoms such as a headache, eczema, joint pain, mood and mental imbalances.

10 Most Common Food Allergies, Sensitivities, and Intolerances

So, what are the top 10 food allergies, sensitivities, and intolerances I see in practice? Here they are:

  1. Dairy
  2. Eggs
  3. Gluten/Gliadin
  4. Almonds
  5. Pineapple
  6. Garlic
  7. Avocado
  8. Mustard
  9. Green/Kidney/Navy Beans
  10. Kelp

Food Allergies Are More Common Than You Think

I would like people to realize – everyone has food sensitivities or intolerances or allergies! In fact, at least 30 to 50% of the population experience them in some form or another. Some of these allergies, intolerances, or sensitivities are genetic while others are acquired throughout life.

If you are curious about which foods will be beneficial to your body, versus which foods can create an inflammatory response, I can do a simple blood test at the Clinic to detect these antibodies. Based on the results of the blood test, I will type up a treatment plan for each patient to address the “damage” that the food intolerances have formed in the body. With time, the patient’s body recovers and the patient feels better overall. I truly believe that diet is the basis for any health plan. These diet plans are also an excellent way to fine-tune and customize a treatment plan for each individual patient.

Feel free to contact me if you have any questions. I look forward to helping you in the future.


In health,

Dr. Sanjay Mohan Ram, B.Sc.(Hon.), N.D.