Food Sensitivity Testing

Food sensitivity testing is one of the tools Naturopathic Doctors use to assess health in our patients.  In Naturopathic Medicine our goal is to find the cause of symptoms of illness and disease.  In a previous article, Understanding Food Sensitivities, I discussed what food sensitivities are and the importance of testing. In this article we will look at the options for food sensitivity testing.

Testing for Food Sensitivities

There are several methods of testing for food sensitivities.

1. Elimination Diet

Most people attempt a food elimination diet as an initial way of self-diagnosing food sensitivities.  A hypoallergenic, anti-inflammatory diet is consumed for a set period of time (usually 6-12 weeks).  All the most common allergenic foods are eliminated and the patient self-monitors for improvements in symptoms.  Foods are re-introduced one at a time after the initial period of restriction.  If symptoms arise on reintroducing the food then a food sensitivity is suspected.

Advantages: Promotes a general sense of well-being, high level of patient involvement in their health.

Disadvantages: Does not eliminate all potential sources of sensitizing foods.  Requires compliance with a restricted diet for a period of time.  Can be expensive (the cost of egg-free, gluten-free, dairy-free, organic food adds up quickly).

2.    Electrodermal Food Allergy Testing

A machine is held by the patient and the electrical frequencies of food are tested against the body’s reaction to those foods (the brain interprets the electrical signal and elicits a skin resistance response which is read by the machine).

Advantages: Painless.  Children can be tested easily.   A clear outline of food sensitivities and the severity of sensitivities is given.  Foods do not have to have been consumed recently for valid results (although accuracy is increased if they have been consumed recently or are consumed frequently).

Disadvantages: Moderately expensive.  Some practitioners do not accept the validity of the testing method.  Test accuracy relies on technician proficiency.

3. IgG Food Sensitivity Testing

A blood test is analyzed by a specialized laboratory to assess for IgG (immunoglobulin G – one of two antibodies produced during an sensitivity response). IgG antibodies are produced for several hours or days after exposure to an allergen (which is one of the reasons why some symptoms of food sensitivity don’t occur immediately after eating a food).

Advantages: Gives a clear outline of food sensitivities and the severity of the sensitivity.  Tests for a wide variety of commonly consumed foods (from 120 to 300 foods).  A simple blood draw is done at a local Life Labs.  Antihistamine use is permitted during the test.

Disadvantages: Can be expensive.  Food must be consumed within 3 months prior to the test for an accurate reading.  Immunosuppressant drugs (prednisone, chloroquine and azothioprine) must not be used during the testing.

In my Toronto clinic I most commonly use the IgG food sensitivity blood test to assess for food sensitivities.  Clinically I have found this test to accurately identify sensitivities and result a corresponding improvement in patient symptoms. I support my patient’s ability to choose whatever testing they find to be ideal and can support that decision making process and help to develop a treatment plan, whatever the testing method selected.

Why is this testing different than that provided by my MD or allergist?

Most severe, immediate allergy symptoms are a result of IgE (immunoglobulin E) – responsible for Type I hypersensitivity reactions in which a food antigen attaches to an IgE antibody and results in an immediate, and potentially life-threatening, hypersensitivity reaction.  Because of this many MDs have limited their testing to this class of immunoglobulins.

There is considerable evidence for IgE testing, but there is also abundant evidence that IgG(immunoglobulin G) is an important marker for food sensitivity testing.  IgG and IgG-complexes are involved in 80% of all food allergy or sensitivity reactions.  IgG is involved in delayed immune responses which are more common in food intolerance.

How can I learn more about food allergy testing?

At my Toronto clinics, I offer Rocky Mountain Analytical’s IgG Food Sensitivity test (RMA FST).  The blood draw is done through your local Life Labs.  You can read more about the RMA FST test here.  You can also book a complimentary 15 minute consult with me to discuss whether or not food sensitivity testing can help you achieve your goals for a balanced, healthy diet.

Disclaimer

The advice provided in this article is for informational purposes only.  It is meant to augment and not replace consultation with a licensed health care provider.  Consultation with a Naturopathic Doctor or other primary care provider is recommended for anyone suffering from a health problem.