Testing for Food Sensitivity

by Dr. Michael Nowazek

It is a common misconception (particularly among the national news outlets) that food allergies and food sensitivities are the same thing. They are not.

The word “allergy” comes from the Greek allos (meaning “different” or “strange”) and ergon (meaning “action”). An allergic reaction is the immune system’s immediately apparent action against a particular substance such as pollen or peanuts or shellfish. It is an immediate onset reaction.

The word “sensitivity” comes from the Latin sentire (meaning “perceive”). Food sensitivities are not allergies; they are a condition that can cause symptoms to develop over a period of time. A sensitivity does not manifest itself immediately; there is a delayed reaction.

One part of your immune system reacts to foods to which you are allergic; a different part of your immune system reacts to foods to which you have sensitivity. Food sensitivity reactions, just like allergic reactions, are an immune system response. Even though your immune system’s response to food sensitivities is very different in that it can take much longer to become obvious and it can affect the body in many different ways, it is still an immune response that should be addressed.

In order to fully understand the difference between the two, it’s helpful to get a grasp of the immune system and some of its different components.

The Standing Army

Your immune system is your body’s “armed forces” standing at the ready to repel antigens. Antigens are infectious organisms or other substances that the immune system recognizes as alien and perceives to be a threat to the body. Like any armed force, it has different divisions (similar to way a country will divide its armed forces into army, navy, and air force). These divisions of the immune system produce different antibodies, blood proteins that respond to and counteract specific antigens.


There are two antibodies that are known to produce food reactions. One of them is Immunoglobulin E (IgE). If you ingest a food to which you are allergic, your immune system instantly responds by producing IgE, which creates an immediate allergic response. If, for instance, someone eats something they are allergic to such as peanuts or shellfish, there is an immediate reaction such as respiratory shutdown or hives. Because the reactions are immediate, it’s fairly easy to identify the culprit food.


The other antibody that produces a food reaction is Immunoglobulin G (IgG). It is this antibody that creates a delayed onset response.

The IgG antibody is also the “long-term” memory of the immune system. This long-term memory is the mechanism that prevents recurrence of some diseases. For instance, if you had measles as a child, the IgG antibodies will “remember” the measles and protect you from this disease for the rest of your life.

There are always a few of the IgG antibodies present to enable your immune system to mount a rapid defense against invaders such as a virus or bacteria that you may be exposed to. The IgG antibodies will marshal against the invader so you can recover quickly, often within a few days or weeks (and, yes, “weeks” can be a fast recovery time from some antigen invasions).

If you are sensitive to a particular food, your body will keep some IgG antibodies available. If you do not have a food sensitivity, it won’t. If you are frequently or continuously ingesting foods to which you are sensitive, your immune system will generate a large number of the IgG antibodies because it thinks you are under attack, and these antibodies will build up. IgG antibodies will bind to the offending food substances to create antibody-antigen complexes.

Interesting cells called macrophages are in charge of removing these complexes from the body. They do this by engulfing and digesting the antibody-antigen complexes. Macrophages are very aptly named. The word itself comes from the Greek makros (meaning “large”) and phagein (meaning “to eat”), so the word means literally that they’re big eaters, sort of a voracious biological Pac Man. But if the antibody-antigen complexes are present in large numbers, the macrophages cannot remove them quickly enough and they start to build up in the body.

This buildup can occur in many places in the body such as bowel tissue, joints, and the brain and cause inflammation. Migraine headaches, obesity, irritable bowel syndrome, arthritis can be caused by the buildup that has occurred over time. Because the reactions are delayed, sometimes by hours or days or even longer, the specific food to which you are sensitive is much harder to pinpoint. You may have been ingesting foods to which you are sensitive over an extended period without realizing that your body has an objection to them.

Food Sensitivity Testing

Because food sensitivities are often not instantly obvious symptomatically, the way to determine if such sensitivities exist is to test for them. Food sensitivity testing measures the levels of IgG antibodies being produced in the body and identifies the foods to which the body is reacting. Once these reactive foods have been identified, a program can be tailored to eliminate them.

There is a large and growing body of evidence to support the clinical benefits of eliminating IgG reactive foods from one’s diet. Numerous studies have appeared in such publications as the British Medical Journal and the US National Library of Medicine National Institutes of Health.

There are laboratories that will perform these tests upon a patient’s request, but if you suspect you may have a food sensitivity that is affecting your health, your wisest course is to consult your naturopathic doctor.

The doctors at Green Apple Health Care are highly experienced in detecting and testing for food sensitivities and will develop a customized program to help you resolve any health problems related to any food sensitivities you may have. Call us today at (780) 485-9468 for an appointment.

Click here for a downloadable version of this article.

Dr. Michael Nowazek

Dr. Michael Nowazek is the Clinical Director of Green Apple Health Care. He brings a wealth of knowledge from his extensive training and his many years experience as a naturopathic doctor.

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