The Hype:
EverlyWell ad: "Do you ever feel like you may have certain symptoms related to foods, such as headaches, stomach pain, or fatigue? You want to try eliminating possible triggers, but you are not sure where to start?"
"Yes, finally!" I thought to myself, discovering an online ad for "EverlyWell," a do-it-yourself, at-home test kit for food sensitivities.
I was almost too eager to pay the $199 charge to get some answers. Promising to measure my “body's immune response to 96 foods that are commonly found in western diets,” I thought this is it, the test I’ve been looking for to confirm what I’ve been feeling all along. Gluten and dairy reactivity were sure to result. I was so excited about the concept, I neglected to verify the science behind it. That is, until my test results came back…
Reality Stings…
And so did that fingerstick! While no reactivity was found to gluten or dairy, all the foods that I normally eat and love (without any side effects) showed positive reactivity. My daily apple for breakfast, lemon and ginger tea with cinnamon, dinners with cashew and mushroom all showed up as “allergies.” This kit tests one thing: what foods you are exposed to, not necessarily allergic to.
The Science:
Guess what? Even the science behind these food sensitivity kits confirms they detect exposure and not allergy. These tests measure your levels of an antibody called IgG, specific for certain foods. The companies advertise that the higher your IgG level is to a certain food (which they detect with a special blood test), the more allergic you are to it. However, this is false. Only IgE levels measure a true, life-threatening allergy to foods called anaphylaxis.
IgG antibodies tested for in these products do not correlate with food sensitivities or clinical symptoms. In fact, IgG levels to certain foods increase with repeated exposure; the more you eat a specific food, the more IgG you will have to it [1]. Moreover, higher IgG may mean that your body has become more tolerant to the food: IgG has been linked to the activity of regulatory T cells, known to induce immunological tolerance [1]. Don’t believe me? Then, take it from the European Parliament Interest Group on Allergy and Asthma: “Laboratory tests based on titrations of [serum IgG] against foods are insignificant in the diagnosis of food allergy and intolerance. They should not be performed in cases of symptoms associated with food consumption [2].” A small study of 12 healthy volunteers included serum tests for a type of IgG against 9 commonly consumed foods (including milk, eggs, peanuts, wheat flour, banana, orange, rice, potato, and pork) [2]. While none of the participants reported any symptoms after consumption of the study products, IgG antibodies against them were present in all participants!
In terms of my own test, I do not eat wheat and dairy because of gastrointestinal side effects, so it makes sense my IgG levels would be low and therefore, undetectable in this “sensitivity study.” (See why I’m gluten free here). I do, however, drink a lot of tea with lemon, which actually makes me feel good, and apparently, EverlyWell claims I should avoid.
Bottom line: Save yourself a needle prick and $200… avoid these at-home food sensitivity scams. When it comes to knowing what foods to eat, just follow your gut. Literally.
References
[1] Gocki J, Bartuzi Z. Role of immunoglobulin G antibodies in diagnosis of food allergy. Advances in Dermatology and Allergy. 2016;33(4):253-256.
[2] Stapel, S. O., Asero, R., Ballmer-Weber, B. K., Knol, E. F., Strobel, S., Vieths, S. and Kleine-Tebbe, J. Testing for IgG4 against foods is not recommended as a diagnostic tool: EAACI Task Force Report. Allergy. 2008;63: 793-796.