This post about food sensitivity tests contains affiliate links.
A food sensitivity is hard to define as it’s a relatively new phenomenon. When someone is sensitive or intolerant to a particular food, he or she may experience gastrointestinal ailments such as bloating, gas and abdominal pain, as well as symptoms like rashes, migraines and fatigue.
Growing interest in food sensitivities has created a new marketplace for food sensitivity tests – and with the creation of this industry comes a lot of questions and confusion. A lot of holistic health professionals are excited to have another tool that allows them to understand how food can hurt and heal a person. On the other hand, many medical professionals skeptical of food sensitivities altogether demean holistic approaches to healing – thereby resorting to calling food sensitivity testing “junk science,” name calling that carries little merit in my book.
While I am pro food sensitivity testing (the more knowledge you have about yourself, the better), I do want to present a balanced look at food sensitivity testing, its accuracy, and how the results of a food sensitivity test should be used to help you overcome your personal health challenge(s).
Food Sensitivity Tests and IgG
You can determine if you have a food sensitivity through a simple blood test. The test will look for how the immunoglobulin G (IgG) antibodies bind to each food and by what degree.
IgG accounts for 75 percent of the antibodies circulating in your blood. Antibodies are an important part of your body’s response to toxins because they recognize and bind to particular antigens, such as bacteria or viruses, and then helps to destroy those toxins.
It’s important to note that an IgG test is a test for a food sensitivity ONLY – not a food allergy. Unfortunately, the terms “food sensitivity” and “food allergy” are used interchangeably, adding to marketplace confusion. (IgE tests for allergies, not IgG.)
Experts believe that IgG reactions can take hours or days to develop, making it difficult to determine exactly which food is responsible for symptom flare ups. This means you can’t always blame the last thing you ate in understanding how a food sensitivity is affecting you.
On one side of the coin, you have researchers say that an IgG subclass, known as IgG4, (which stands for immunoglobulin G4), is simply a marker of exposure to a particular food and possibly signifies a person’s tolerance – not intolerance – to that food.
On the other side, a researcher found that IgG testing showed “promise,” netted “clinically meaningful results,” and could serve as a “useful as a guide for elimination diets.” Another article published by an otolaryngologist found the majority of his patients experienced “substantial health improvements after an elimination of foods positive by IgG food allergy tests.”
What this all means is two-fold.
One, it means that more research is needed to understand the accuracy of tests for food sensitivities, and two, it means that food sensitivity tests should not be on the only diagnostic tool used to determine your food intolerances (i.e. you should go on an elimination diet to complement/confirm your food sensitivity test findings).
(Of note, many medical and diagnostic procedures are controversial but still widely recommended and used among the medical community. One procedure that comes to mind is mammograms. Before the Internet attacks me, please know that I am mammogram neutral. I only say this to illustrate the point that there are differing viewpoints when it comes to understanding how to diagnose and test for disease in our bodies.)
Limitations to Food Sensitivity Tests
While I encourage everyone who believes they have a food sensitivity to purchase a food sensitivity test, I recommend you proceed cautiously optimistic. The verdict is still out whether such tests are 100 percent accurate. Tests can come back with a wide array of possible trigger foods, causing you much anxiety as you try to figure out what to eat.
However, knowledge is power. I believe these food sensitivity tests should be used as a starting point on your journey to figure out what ails you. You are your best scientist. I believe we will all be better off if we stop relying on our doctors, who have little-to-no nutrition education, to fix us. You have the power to heal your body, put your chronic symptoms to rest, and possibly reverse disease in your body.
How Should Food Sensitivity Tests Be Used?
In my opinion, food sensitivity tests should not be used as a diagnostic tool, rather as a starting point to an elimination diet. You can eliminate the foods that you are most sensitive to first for at least THREE weeks (maybe four), then over time, add each food item back into your diet to see how you feel. For example, if you eliminate eggs, corn and dairy for three weeks, you can first add eggs back into your diet and see how you feel over the next few days. If you feel fine, then a few days later you can add corn back in and so forth. Go slow and don’t rush through the process.
Food Allergy Tests
As mentioned, IgG tests do not test for food allergies. This is an important distinction as an allergy and a food sensitivity are not the same. When I was tested for celiac disease (via a blood test), I was also tested for food allergies to cow’s milk, wheat, corn, peanuts, soybeans, pork, beef, fish/shellfish, egg (whole) and chocolate/cocoa. I am thankfully not “allergic” to cocoa. Whew!
In a fascinating twist of fate, however, my IgE food allergy tests came back positive for wheat (class I), corn (class II) and peanuts (class III). This meant not only did I have high levels of t-Transglutaminase (tTg) IgA (which indicated celiac disease) but also I had elevated IgE levels when it came to wheat! I had tested positive for both an autoimmune response and a histamine (allergic) reaction to wheat. (In case you’re wondering, I confirmed my celiac disease diagnosis with a biopsy, which you can read about here).
In my research for this post, I learned that many patients with celiac disease also have a food allergy to wheat, gluten, gliadin, rye or barley. Who knew?!? (Source: Clinical Usefulness of IGG Food Allergy Testing)
How to Get a Food Sensitivity Test
With the rise in popularity of food sensitivity awareness, so comes the flood of at-home testing products. I believe that many doctors are hesitant to order food sensitivity tests for their patients because enough research on testing methods has not been done – and many doctors are not trained to help their patients interpret and act on the results. Because of the disconnect between patient desires for a food sensitivity test, and a doctor’s hesitation to order one, many patients are resorting to self-help.
I researched a few of the big food sensitivity names on the market, and finally settled in on Everlywell as the one I wanted to try for myself. Some of the tests did not feel right to me, and Everlywell has an excellent reputation. (UPDATE: Everlywell secured a partnership with Lori Greiner on Shark Tank!)
For $199, Everlywell sent me an at-home blood test I could do with a prick of my ring finger. You can watch me do the test (and blood draw) in this video. (You can view my food sensitivity results in this post.)
Please note that while I don’t work for Everlywell nor endorse the product in anyway, I am an Everlywell health practitioner partner. This means my clients get 10% off (when they use my coupon code “GFJenny” at check out here) and I get a small percentage of the revenue in return. Please know, however, that I do not recommend one food sensitivity test over another, I only have tried this test in my own pursuit of understanding how other foods, besides gluten, may be sabotaging my health.
(If you are testing just for a gluten sensitivity, consider talking to your doctor first. Many experts say Cyrex Labs is the gold standard for gluten sensitivity testing, so it’s worth your time to research this in earnest. I wrote about gluten sensitivities in this article, “Why Gluten is Toxic to All Humans.”)
After the Results
I write more about what to do with the results of your food sensitivity test in this article but for the most part, you should take the information with a grain of salt. Don’t let yourself become overwhelmed with the idea of having to eliminate every possible sensitive food all at once.
Instead, use the results of your food sensitivity test as a means to do some simple experiments on yourself, over time. Go easy; this is a marathon, not a sprint.
I recommend you eliminate the top foods (the ones with the highest IgG ranking) for three weeks. Then, slowly over time, reintroduce each food one-by-one and see how you feel. You will likely know, at this time, which foods bother you and which do not. Continue to eliminate and reintroduce foods until you get to the bottom of what is ailing you most. I recommend you work with a trained holistic health coach or other health care professional during this process.
Again, you are your best scientist and detective. No one can figure this out but you – these food sensitivity tests just give you a starting point.
Prognosis of Food Sensitivities
It’s important to know if food is sabotaging your health and do something about it if you want to feel better and deter chronic disease.
In fact, ignored food sensitivities may lead to the development of chronic conditions including but not limited to autoimmune disease, behavioral problems, psychological disorders, diabetes, hyperthyroidism, infertility, neurological conditions, obesity, osteoporosis and more.
Continued consumption of foods you are sensitive to may also contribute to weight gain or difficulty losing weight. (Source: Dr. Rita Marie Lascalzo). Jennifer Fugo of The Gluten School often talks about how she quickly shed 20 lbs of “inflammation weight” once she realized she had a gluten sensitivity and therefore eliminated gluten from her diet.
What Should You Do?
For me, I decided to get a food sensitivity test. I err on the side of knowledge is power vs. ignorance is bliss. Plus, my results will give me a starting point for my own elimination diet. I believe that we all need to take charge of our health and not decide on whether or not we do a test based on the opinion of others (even doctors) who may not have researched food sensitivities in earnest. Research is continually changing, and I may be proven wrong one day, but for now, my gut tells me this kind of information is powerful in aiding in my healing journey.
UPDATE: Read about the results of my Food Sensitivity Test!
What Do You Think?
Please leave a comment below.
Do you want to get a food sensitivity test?
If you’ve been tested, what did you find out and how did it impact your life?
Please share. Thank you!