Is Food Sensitivity Testing Worth the Expense?

A variety of food sensitivity tests are accessible to consumers these days, and often at a high out-of-pocket expense. Unlike true allergy testing, food sensitivity tests claim to detect non-allergic sensitivities to foods that can cause inflammation in the body which in turn can contribute to the progression of a variety of diseases. Offered by clinical laboratories, as well as independent producers of these food sensitivity testing kits, these services typically cost between $100 - $300. But do they in fact measure what they claim to measure? In short, there is little, if any, evidence to support that these tests accurately measure food sensitivities. With that said, let’s dive into the details.

Food Allergies vs. Food Sensitivities

True allergies are mediated by our immune system, in particular, our IgE immune system. When allergy blood tests are conducted, they look for IgE antibodies in the blood, which can be found in larger amounts when an individual has an allergic response to certain foods. When the particular food allergen is eaten, IgE antibodies trigger an immune response that releases histamine and other inflammatory messengers which lead to allergic reactions.

Food sensitivity is a general term that encompasses a number of things, including food allergies, health conditions such as Celiac disease, and food intolerances. Food sensitivity testing is generally geared towards food intolerances. Unlike food allergies, the IgE immune system cascade is not activated when an individual consumes a food that they are intolerant to.

Food intolerances can occur for a number of reasons. For example, deficiencies in certain enzymes can lead to incomplete digestion of food and result in uncomfortable gastrointestinal symptoms, such as in the case of lactose intolerance. Irritable Bowel Syndrome, or IBS, is another cause of food intolerance. Some people have sensitivities to certain food additives such as sulphites, causing reactions when foods containing these additives are consumed. Finally, individuals can experience uncomfortable digestive symptoms when eating certain foods due to psychological reasons.

Common Types of Food Sensitivity Testing

IgG Testing

IgG testing measures levels of IgG and IgG4 antibodies in the blood to determine food sensitivities. This form of food sensitivity testing is the most common and is offered through some clinical laboratories. Proponents of IgG testing claim that higher levels of IgG antibodies in the blood indicate an intolerance to a particular food or foods, and usually large panels of various foods are tested for. The reality is, most people develop these antibodies to many foods that they eat, and this is considered a normal immune response to food consumption. IgG antibodies are considered a marker of exposure to a particular food, not a sensitivity.

For the Canadian Society of Allergy and Clinical Immunology (CSACI) position statement on testing of food specific IgG, click here.

Electrodermal Testing

Electrodermal testing, or VEGA testing, is conducted with a device that measures electromagnetic conductivity in the body. While various allergens and chemicals are being tested, a drop in electromagnetic conductivity indicates a sensitivity/intolerance. To date, no quality evidence exists to support the use of electrodermal testing in identifying food sensitivities. In fact, one study showed that VEGA testing failed to identify individuals with previously confirmed allergies (via skin prick test) to house dust mite and cat dander allergens versus individuals who tested negative.

Hair Analysis Testing

Hair analysis testing is used to identify toxic levels of heavy metals, for example, lead and mercury, and evidence exists to support its use for this purpose. However, quality evidence is lacking to support the use of hair analysis testing to identify food allergies or sensitivities.

What to do if you suspect a food intolerance

If you suspect you are intolerant to a particular food or foods, talk to your family physician. It is important to be assessed by a medical doctor to rule out any other potential causes for your symptoms. Speaking to a Registered Dietitian can help you to identify and eliminate certain food triggers while ensuring a nutritionally balanced diet is maintained. Keeping a food journal which tracks your meal times, types of food eaten, and symptoms post meals, can also be helpful in narrowing down food intolerances. Overall, food sensitivity tests are not supported by quality scientific evidence, so best not to part with your hard-earned money!

By: Pauline Bakowski, MHSc, RD
Reviewed by: Kristie Pun, MHSc, RD & Cheryl Ching, MSc, RD

Disclaimer: Our blog content is for general education purposes and may not be suitable for individual health conditions. Please see your health professional or book an appointment with one of our dietitians for personalized health recommendations.