Food Sensitivities - Fact or Fake?
Updated: Jun 8
Every so often, the media or some IG influencer issues a report that bashes food sensitivity testing as a helpful tool in overall health.
They'll bring on experts to tell us the test are "unsafe" and encourage people to eat more of the food that comes up in their results to build a better immune response.
I am not a doctor, and I look at things through a nutritional lens based on my 10 years experience in working with food sensitivity tests.
I believe whole heartedly in food sensitivity testing - and temporarily avoiding what comes up (with the intention of adding these foods back in).
Why? Because I see results personally and professionally.
Most major labs in North America offer IgG testing, and it is used by numerous health professionals in North America, including physicians, naturopathic doctors and nutritionists (like myself) as a tool in developing a customized health plan. In fact, my mainstream family MD recognizes results (her clinic provides them), as does the functional MD who treats my daughter for her autoimmune condition. Yet, our paediatrician does not.
Each expert has their own reasoning, and that makes it confusing.
Who should you believe?
The immune system is complex. As a certified nutritional practitioner, I can only provide advice within my scope of practice. And you should absolutely listen to the advice of your doctor or another credible health care professional when considering any sort of testing. Do your research. Make smart, informed decisions.
And consider this article "food for thought" as you weigh options.
What is IgG testing?
In short, a food sensitivity test measures the amount of immunglobulin G (an antibody - a "fighter that protects your body") in response to an antigen (an antagonist, a foreign invader the body doesn't recognize or perceives as a threat).
What does that mean?
"When your body feels it is under attack, it makes special proteins called immunoglobulins or antibodies. These antibodies are made by the plasma cells. They are let loose throughout the body to help kill antigens like bacteria, viruses, and other germs. The body makes 5 major types of immunoglobulins:
Immunoglobulin A (IgA)
Immunoglobulin D (IgD)
Immunoglobulin E (IgE)
Immunoglobulin G (IgG)
Immunoglobulin M (IgM)
Immunoglobulin G (IgG) is the most common type... IgG is always there to help prevent infections. It’s also ready to multiply and attack when foreign substances get into the body." John Hopkins Medicine on IgG deficiency and why it's important to have IgG antibodies in your system.
So, our bodies produce antibodies - immunoglobulins - as a protective mechanism against foreign invaders.
When someone has an allergy (food, animals, environment, chemical), there is an immediate and measurable immune response. The most common immunoglobulin measured is IgE.
When there is an IgE response, typically, your response is fixed - it is there for life, or at least a long period of time.
An IgE reaction indicates a systemic immune response to the invader (like anaphylaxis, asthma, runny nose, itchy eyes, dermatitis). Other immunoglobulins are sometimes measured (like IgA - the mucous response), but IgE is the most common one measured when you visit an allergist.
To diagnose allergies, the most common test is the "scratch test" whereby the allergist pricks the skin, allowing a small amount of a protein to enter the blood stream. The reaction is always to the protein in the substance, and immediate - usually 15 minutes.
Doctors diagnose allergies by this reaction - redness, swelling, itch. Doctors will sometimes use blood tests, when a skin test is deemed too dangerous (skin infection).
This test is important and can save lives. In the case of anaphylaxis (a life threatening allergy), allergists are a key part of the team. In no way do I mean to discredit the profession.
My understanding is that "allergies" that mark an IgE response are typically fixed - meaning there's a good chance you have them for life. I have lots of fixed allergies. But I also have lots of IgG responses (food sensitivities), which I will get into next.
I've asked three allergists about IgG testing (two of mine and one for my daughter), and they have all told me time-after-time that IgG food sensitivity test is unreliable because I can have a positive reaction one test and negative the next test. There is no concrete, immediate reaction.
YET ... they have also told me the scratch tests for food are sometimes unreliable - doctors don't like performing them.
So, let's look at my personal experience.
I have seen allergists all my life - repeatedly, some years. And they have been helpful and improved my quality of life in various ways. For example, I have always been extremely allergic to cats, dogs, mold, horses, rabbits and birch trees. I've had shots, sprays and pills which have helped make the allergies more bearable. But, they are still there.
My environmental allergies have never gone away although some have gotten worse and others have gotten better.
I've also been told over the years that I also have food allergies.
Peas, peanuts, oats and oranges were high when I was young, and my most recent visit to the allergist (2016) confirmed they are no longer an issue. The doctor said I was no longer allergic.
YET, I've developed new allergies ... hazelnuts which now requires an epipen. I had to push for this testing ... insisting that "mixed nuts" made my mouth itch. She didn't want to test for food, but when she did ... voila. Now I have an allergy.
I asked specifically about gluten and dairy. Am I allergic to those foods? Could she test for those? Why did I break out in eczema and get ulcers in my mouth when I ate dairy or wheat? She didn't have a response because I didn't show a response to those foods with the scratch test. She said I was not allergic.
But I know that I react.
I was thankful that we figured the hazelnut thing out, but left my appointment frustrated.
What is a food sensitivity test?
This past summer, I did a food sensitivity test with Great Plains Laboratories - the facility I use for all my client testing.
A food sensitivity test marks your body's IgG response to 190 tested foods, plus the ability to add on candida antibodies to rule out if a person is reacting to yeast overgrowth (or the food) and to help me identify the best anti-inflammatory diet as a result.
Remember, an IgG is a reaction to a perceived threat and is typically the target of people who say they are unreliable or a waste of money.
Here's how the test works ...
It's a dry blood spot test, meaning, you take a few drops of blood at home, and send your results back to the lab. The lab then marks the IgG response to proteins in 190 common foods. They use a colour scheme for the tested foods along with a number score. The foods in red should be avoided, yellow in moderation and green, no worries. The marking scheme is based on the IgG response.
It then becomes my job to determine how to reduce exposure to these foods, find easy substitutes and map out a schedule for reintroduction.
I get my report back.
Remember those foods that were "fixed" when I was young and disappeared as an adult?
Well, some showed up on that list, as did some new foods. So, according to the food sensitivity test, I'm still reacting to some of my previous allergies and now reacting to more nuts than simply hazelnuts.
Wheat and dairy were also there. But according to the allergist, I'm not allergic to wheat or dairy, despite the eczema and ulcer connection.
I'm given an epipen for a hazelnut allergy (a tree nut) that makes my mouth itch.
I break out in eczema and get ulcers in my mouth when I eat wheat and dairy, but I'm not allergic.
And if I listen to naysayer's reports, I should eat MORE of my food sensitivities - other tree nuts, wheat and dairy - despite the fact I react with mouth ulcers and eczema.
Why I recommend food sensitivity tests as part of an anti-inflammatory diet
In my professional and personal experience, depending on your state of health, you can have heightened sensitivity to what is entering your body.
State of mind, chronic inflammation, stress, physical injury, toxic overload, leaky gut and bacterial imbalances can all negatively influence your body's immune response and can contribute to food sensitivities.
Hundreds of books have been written on this subject by various inflammatory experts - MDs and NDs alike.
This is a very simplified summary.
When you are in a state of good health, your body is better able to process a wide variety of foods with little effort. This is no different than being able to fight off a cold/flu that is going around.
However, when you are have chronic, lingering health issues, you might react to certain foods that wouldn't normally bother you because you're already in a pro-inflammatory state.
Remember, 70% of your immune system is found in your gut. I think it's safe to say that if your gut isn't in good health, your immune system may be compromised and not behaving the way it should.
I recommend food sensitivity tests under certain conditions:
You have already tried an elimination diet like Paleo, AIP or even gluten free, and feel you're still reacting to certain foods and aren't able to pinpoint what food is bothering you.
You have a hard time sticking with nutritional recommendations (like AIP, Paleo or other) and want to follow a nutritional list of foods that is customized to you. This has more to do with compliance, needing a super clear list of Yes's and No's.
The reason why I recommend food sensitivity tests under these situations is to eliminate any possible external triggers - exterior irritants - that may cause an additional inflammatory response. The goal is to let the body CALM DOWN. Reduce overall inflammation so your body can focus on healing and return to balance.
Make sense? It does when you consider the role of IgG - to defend the body against against what it perceives as foreign invaders.
The usual protocol is to remove these foods for three to four months, during which time you really make an effort to reduce internal inflammation. For some that may mean herbs to address bacterial imbalances. For others that could mean starting a new supplement regime to address your key health concern. You then reintroduce one food at a time to see if your body still reacts.
Reactions can take up to four days, so it's important you REALLY pay attention to how you feel - physically and emotionally. It can vary from person to person. Here is a short list of possible reactions
Skin: itchy, dry skin, eczema flare, hives
Brain: headaches or migraines, brain fog, irritability, mood swings, difficulty concentrating, hyperactivity
Digestion: constipation, diarrhea, stomach pains, gas/burping
Other: aches/pains, sinuses, disrupted sleep, urinary incontinence
If you are still reacting, we remove the trigger food for another few months, and so on. The goal is to get you back on track, eating all the foods you want to enjoy. However, unless the underlying reason as to WHY there is inflammation is not resolved, the food sensitives may linger. The process is not black and white. It's individualized and a journey.
In my case, I had been reacting to gluten and dairy for a few years, yet was encouraged to keep eating it because the negative celiac blood test and allergy tests kept coming back negative.
In 2018, I tested positive for the primary celiac gene in addition to an IgG sensitivity. It is not a diagnosis for celiac, but given the fact I get mouth ulcers and eczema, my family doctor, rheumatologist and dermatologist have unanimously advised I stay away.
This is where critics of IgG testing really miss the mark. They look only at the test and not the application or individual's larger health history or symptoms. Nor do they address the many root issues as to WHY a person would be reacting to foods and HOW to go about bringing things into balance.
Navigating food sensitivities when you have an autoimmune or inflammatory condition
Living and working around food allergies or sensitivities doesn't have to be limiting. Many of my clients panic when we look at food sensitivity test results that look like a Christmas tree of red, yellow and green, but once they realize, "hey, there are lots of great things I can eat," and I give them tools to cope ... they start to FEEL BETTER. And feeling better provides the ticket to being able to handle these restrictions with ease.
The good news is that there are so many options and substitutions you can draw on. I encourage you not to dismiss food sensitivity testing if you have a chronic health issue based on one bad review or naysayer.
The results can be helpful and liberating in your overall health plan.
If you're interested in learning more about whether food sensitivities are a good option for you, send me an email and we can chat to see if it makes sense for your health goals - Click Here For More Information.