Food sensitivity testing has boomed over the past few years. Many patients come into my office inquiring about this test, and it’s something that comes highly recommended by functional medicine practitioners to help isolate foods that might be exacerbating underlying conditions.
While the hopes are high with these tests can isolate food sensitivities, it's important to understand exactly what the results are telling you, and their possibility for inaccuracy depending on the method of assessment. More importantly, my concern becomes the possible nutritional deficiencies and unnecessary stressors of food avoidance on patients following excessively restrictive diets that can amount from these tests. In the end, always speak to a medical professional before ordering and testing and restricting your diet based on the results.
What is Food Sensitivity Testing?
Not to be confused with an allergy, IgG or “Food-Specific immunoglobulin G” intolerances are immune-mediated reactions which occur as IgG antibodies bind to a food antigen in the body, creating antibody-antigen complexes. Unlike anaphylaxis, this is considered a Type III delayed hypersensitivity reaction, and while these reactions are harmless in low numbers, a high volume of IgG antibodies has been associated with increased inflammation and a wide variety of symptoms.
Since Type III delayed hypersensitivity reactions can typically occur over several hours to several days, it can be very challenging to isolate food intolerances via dietary journaling or elimination. This is where food intolerance testing may provide value.
Why do Food Intolerances Occur?
While research is still exploring impacts on our gut barrier, it appears the most common aggravators to our intestinal lining and probable development of food intolerances are:
Gut dysbiosis
High saturated fat and high sugar diets
Poor dietary fibre intake
Smoking
Excessive use of NSAIDS
Stress
Furthermore, chemicals and additives in our diets that have been correlated to negative impacts on our microbiome and gut barrier are:
Artificial colourants
Flavour enhancers (monosodium glutamate or MSG)
Sulphates (found in alcohols and some medications)
Preservatives (benzoates, sorbates)
Sweeteners (aspartame)
Things to consider when testing
The most important factors to consider when ordering an intolerance test are:
Method of collection:
Food intolerance testing should be collected via blood sample, measuring a quantifiable number of IgG antigen-antibodies complexes made to specific foods in your diet. Some complementary medical practices will offer intolerance testing via electrodermal screening, which is the use of computerized testing gathering feedback from energetic meridians and is not backed by literature. As such, I always advise serum assessments for my patients.
Current medications:
Remember that antibody testing relies on your measuring immune complexes, and therefore cannot be completed if you are taking immunosuppressant or steroid-based medications. These medications work to suppress immune-mediated reactions and will result in false negatives. It's also important to avoid testing when your body is having a severe inflammatory reaction, and you’ll likely see numerous false positives.
What the results are telling you:
The results will provide you with a list of foods that have associated IgG immune-mediated reactions, as well as a quantified number of antibodies that indicate the severity of the reaction, however, what it does not guarantee is the reactions’ correlation to your symptoms. Literate has shown a probable correlation of IgG reactions to conditions such as migraines, IBS, ADHD, rheumatoid arthritis, weight gain and dermatitis, but running testing does not mean that every food that shows up on your list is the source of your health issues. The process of elimination is still advisable to draw cause and effect between the results and your concerns. Speak to your naturopath about how to do this properly.
All in all, food intolerance testing can certainly have the potential to provide value when looking to understand foods’ correlation to your underlying health concerns or overall well-being. What's most important is to understand when testing is indicated, and when it may not be advisable.
To find out if food intolerance testing is right for you, or to explore other possibilities in how to isolate food’s influence on your health, contact Dr. Courtney Holmberg, ND at 647-351-7282 or visit us online to book an appointment.