The Non-Bogosity of IgG4 Food Intolerance


Recently, I received an email which was a generic mass mail-out Christmas card from a former childhood friend whom I have not kept in contact with for about a decade now. She and her husband run a beautiful and successful B&B.

This is what she wrote:

"Though our guests were wonderful, we did face some challenges in the food department. “Trending now” are guests with food “allergies” based on whatever foods the media popularizes as those we should avoid. Since these “allergies” are trends and not real “issues” we find that despite having many opportunities to let us know about their food issues, guests "forget" to let us know until they arrive.  Arggghhh.  This throws a big monkey-wrench into the food planning and results in our having to serve 8 different breakfasts on any given day to satisfy all the food "allergies" around the table.  August was a particular challenge but we made it through.  Our guests of course are grateful for the care and attention we provide and we really do want them to have great experiences, but it can wear one out after awhile."

Her use of quotation marks around the word “allergies”, and her assumption and maligned statement that food challenges for people are only trends and “not real issues”, speak volumes about her lack of knowledge regarding food intolerances (most likely IgG4 Type III hypersensitivity reactions) and how they adversely affect many people.

I have been doing IgE and IgG4 ELISA food allergy testing on many patients for the past 18 years. I have found it to be a very valuable test, and that is why I continue to recommend it to those particular patients whom I believe would benefit most from it.

In March 2012, CBC put out a story and wrote:

(Dr. Elana) Lavine says doctors should tell their patients about the controversies surrounding testing for food sensitivities, including the fact that there is no proven role for using readings of antibodies called IgG in testing for food allergies.”

The blogging world also weighed in, and in his article “IgG Food Intolerance Tests: What does the science say?”, Scott Gavura, a pharmacist from Ontario, wrote this in his concluding statement:

At present, there are no reliable and validated clinical tests for the diagnosis of food intolerance. While intolerances are non-immune by definition, IgG testing is actively promoted for diagnosis, and to guide management. These tests lack both a sound scientific rationale and evidence of effectiveness. The lack of correlation between results and actual symptoms, and the risks resulting from unnecessary food avoidance, escalate the potential for harm from this test. Further, there is no published clinical evidence to support the use of IgG tests to determine the need for vitamins or supplements. In light of the lack of clinical relevance, and the potential for harm resulting from their use, allergy and immunology organizations worldwide advise against the use of IgG testing for food intolerance.”

This is simply not true carte blanche. This is only one view of food intolerance testing, albeit, well written and supported by the studies Mr. Gavura has cited, but is not true for all people.

This is one reason why I write this blog.


If I had lived my life, raised my children, and practiced medicine, only based on the confines and restrictive parameters deemed by the religiosity of science-based medicine (which I might add, was proudly part of for 10 years during my early days as a critical care registered nurse), - many people whom I love, have cared for, or whom I have met in clinical practice, would not be experiencing good health today.

Case in point. My youngest daughter, who is now 19 years old, gave me permission to share her case history on this blog.

B.G. was an IUGR baby, 3 lbs. 11 oz., born at 37 weeks gestation by emergency induction because of anhydramnios. For the first 2 1/2 years of her life, she experienced numerous and multiple infections (at least twice per month), one of which required hospitalization for RSV at 3 months of age. These frequent illnesses included otitis media, gastroenteritis, bronchiolitis, bronchitis, pneumonia and numerous types of URIs.

Our pediatrician in Ontario at that time, told me that B.G. would continue to be a very sick child even as she grew older, and she would have life-long respiratory difficulties because of my gestational history.

At that time, I said to myself: “ENOUGH. This is bullshit. There must be other reasons why her immune system keeps on plummeting and why she is so sick all of the time”.

Back then, I had only been practising naturopathic medicine for 2 years, and while the natural remedies I gave her at that time prevented, what could have been numerous hospital admissions instead of just one, they were not addressing the root cause of her chronic susceptibility to infections.

At 2 1/2 years of age, I did an IgE and IgG4 ELISA food allergy test on her. I knew she did not have any IgE food allergies since she did not have any immediate reactions nor any anaphylactic reactions after eating any particular food.

However, her tests came back with numerous IgG4 antibody reactions (delayed hypersensitivity intolerances) to many foods. I immediately removed all of the offending foods from her diet, and she immediately and “miraculously” stopped having recurring infections of any kind. As the years went on, if I relapsed with her diet and gave B.G. her offending foods, she would quickly become ill again. When I removed them again, she regained her health just as quickly.

Her health for the past 16 1/2 years has been excellent. Now, when she eats foods for more than 4 – 5 days in a row that she has an IgG4 reaction to, she notices the appearance of various types of symptoms: eczema on her knuckles, ear aches, upper respiratory infections, and on the rare occasion, a small thyroglossal cyst. When she continues to remove these offending foods from her diet, she experiences no symptoms at all.

Over the past 16 1/2 years, I have repeated this ELISA test on her 3 separate times to see if anything had changed. There were very minor changes noted, and again, we continued to follow and be guided by the results of this testing in order that she continue to experience excellent health.

I can already hear the song and dance of the rigid science-based medical experts:

"Your child just outgrew her severe recurrent childhood illnesses as she matured, and the change in her diet coincidentally started at the same time she dramatically started experiencing excellent health".  Spontaneous healing, they would call it. Yeah, right.

And of course, the other old adage: "You know Kathy, this could easily be a placebo response". Yeah, right; a 16 1/2-year placebo response from the age of 2 1/2.

B.G.'s case is one of my more personal experiences I have had with IgG4 testing and it's validity in clinical practice.  My practice is filled with patient anecdotes like this one, and some, of whom have had very serious illnesses.

Is everyone who gets this type of testing helped with their health? Of course not (naturally, presuming strict compliance!). But many do benefit from the information obtained from this test.

I don't know of one medical test that is helpful for everyone.

Even though mammograms are useful for breast cancer detection, they don't detect the presence of cancer in all women, and conversely, mammograms at times, can also reveal false positive results that sometimes lead to unecessary invasive treatment. And don't even get me started on the sole TSH blood test used in order to determine thyroid dysfunction.  Too many women are prescribed Synthroid, only to continue experiencing debilitating hypothyroid symptoms, but now have a “normal” TSH badge to show for it because they are on a gold standard medication determined by a gold standard blood test.  Jeez. And what about echocardiograms that are clearly valuable for the diagnosis of various heart abnormalities, but have their own well-known documented limitations that can produce dramatically different results depending on the technician and the machine? (and of which I have recently had a scary and personal family experience with).  Again, these are all very useful tests, but they are very imperfect tests.

There is no perfect test. There never will be. Why?


People are individuals, with their own unique biochemistries, unique genetics, unique personal backgrounds and experiences, unique environmental exposures, and unique beliefs.

Stating that there are certain therapies or tests that are bogus because they do not fit into the narrow criteria of randomized blinded clinical control trials, is a practice of arrogance at its highest. It is arrogance at its highest, because it does not allow any room for open-minded thinking regarding the possibility that excellent health can be obtained through alternative ways in situations where science-based medicine does not provide effective nor suitable answers for all people.  It is arrogance at its highest, because it consistently chalks up efficacious alternative answers experienced by many people, to spontaneous healing or to placebo response.

Dr. Lauren Russel N.D. and Dr. Leah Alvarado-Paz N.D, in their article “IgG Allergy Testing” published in the Townsend Letter, wrote:

While the mechanism associated with IgG-mediated food allergy may as yet be unknown, the results achieved from serum IgG assessment are very clear and provide a valuable means of designing effective treatments.”

These doctors too, cite many studies that support their position.

As a clinician, I concur with the opinion of these two doctors because it is what I have repeatedly observed in practice for almost 2 decades.

Let me come back full circle to the email sent by my childhood friend.

She has a valid point when she expresses frustration regarding her clientele who do not have the courtesy to inform her well in advance of their food intolerances prior to their arrival at her B&B. I have empathy for her regarding this issue. When I travel, unless I am in a very large city, I just assume hotels and restaurants will not provide me with the meals I require to maintain excellent health. I make arrangements well beforehand to buy my own food at grocery stores while there, or I bring my own food with me when I travel.  I know this particular woman to be someone who puts all of her energy, heart and soul into providing phenomenal hospitality service to all of her customers, so providing 8 different breakfasts at her B&B because clients have not thought ahead of time to inform her about their food intolerances, could be annoying to say the least.

However, and ironically, the last time I saw this woman and her husband, they were both obese and had been so, for the many years I had known them. In her Christmas mail-out, she writes that they are presently both healthy but are experiencing some health challenges, which include acid reflux and osteoarthritis.

And the final irony? Obesity, osteoarthritis and acid reflux are all conditions I have observed in clinical practice, that have improved with the elimination of foods found through IgG4 testing, and are often the very causes that this former childhood friend believes are 'not real issues'.

At the end of the day, the real issue is ignorance and the lack of knowledge regarding what is possible.