Food sensitivity tests: the good, the bad, and the ugly

Kristen Eleanor
Apr 9 · 4 min read

Everyone wants to know what foods to eliminate, but at what cost?

Photo by Polina Tankilevitch from Pexels

The search phrase “food sensitivity tests” returns over 235 million results on Google. These results are heavily populated with advertisements for different at-home food sensitivity testing kits, desperately trying to sell a solution to the searcher’s query.

While well-intentioned, these food sensitivity tests are not all chalked up to what we think they may be. Outside of allergy testing, science does not yet have the ability to tell us exactly what we should and should not eat.

While some methods of identifying and ruling out food sensitivities could be helpful, they shouldn’t cost $900 a test. Let’s dive into the good, bad and ugly behind food sensitivity tests.

First things first: food allergies vs. sensitivities vs. intolerances

Let’s get some technicalities out of the way. Food sensitivities are different than food allergies or intolerances.

Food allergies occur when the immune-system produces IgE antibodies to certain foods, causing mild to life-threatening symptoms [1].

Food intolerances are often related to a mechanical or biological issue with the digestive system, such as lactose intolerance.

On the other hand, food sensitivities don’t really have a formal definition. Rather, they refer to a broad group of unspecific digestive symptoms such as bloating, gas, constipation, diarrhea and abdominal pain.

In this article, we are talking about tests to identify food sensitivities.

The good

Identifying food sensitivities with food journals & a dietitian

Food sensitivities are real. For example, 70% of those living with irritable bowel syndrome (IBS) with sensitivities to fermentable carbohydrates report their symptoms interfere with their everyday life and half report missing work or school due to IBS [2].

Food journals can help individuals identify their food sensitivities with the guidance of a registered dietitian. While it may seem old-school, technology has evolved beyond pen and paper, with some dietitians using mobile-applications with artificial-intelligence to track what you are eating.

For those with IBS, the low FODMAP diet has emerged as an effective dietary strategy to eliminate common food sensitivities. One scientific review suggests that the diet can improve symptoms in up to 86% of IBS patients [3].

The combination of using a food journal and working with a dietitian to undergo a low FODMAP diet is considered safe and effective for identifying food sensitivities. Depending on the dietitian and the length of follow-up, this method may cost you around $300-$500 but can give you a sustainable diet for life.

The bad

Identifying food sensitivities with an IgG food sensitivity test

Any google search for food sensitivity tests will usually show results for IgG blood tests. See this website for an example.

What is an IgG blood test? Supposedly, these antibodies attach to the foods in our bloodstream we can’t tolerate, claiming to be a marker of sensitivity.

Given the lack of reliable scientific evidence to support this claim, and the fact that foods are unrecognizable after being digested and absorbed into the bloodstream, IgG blood tests smell like BS.

Beyond BS, the Canadian Society of Allergy and Clinical Immunology (CSACI) put out a statement warning consumers against IgG food sensitivity tests, stating that “ [IgG tests] only increase the likelihood of false diagnoses being made, resulting in unnecessary dietary restriction and decreased quality of life.

IgG food sensitivity tests only increase the likelihood of false diagnoses being made, resulting in unnecessary dietary restriction and decreased quality of life.

The CSACI also states that the presence of an IgG marker to a specific food in the blood is an indicator of tolerance to a food, the opposite of an intolerance or sensitivity. Other reports suggest that IgG blood tests will simply pick-up on the foods you have recently eaten before the blood test, and have no indication of a real sensitivity [4].

The real kicker? IgG food sensitivity tests can cost as much as $700 per test, often with zero health care professional guidance.

The ugly

IgG food sensitivity tests can cause real health harms

Besides their astronomical prices, sketchy-science and even warning from professional associations, IgG food sensitivity tests could cause real harms to human health.

IgG food sensitivity tests may confuse those with real allergies

The CSACI warns that for those with real food allergies with IgE antibodies, their allergen likely won’t to appear on their IgG food sensitivity test, risking reintroduction into the diet.

This is because the levels of IgG antibodies are lower for those with a true allergen. If you have a food allergy, risking the reintroduction of this food can be potentially deadly.

IgG food sensitivity tests can cause restrictive dieting

IgG is a memory antibody that develops after regular exposure to the foods we commonly eat [5]. This means that your IgG food sensitivity results are likely to indicate that you are sensitive to all the foods you enjoy regularly.

Your IgG food sensitivity results are likely to indicate that you are sensitive to all the foods you enjoy regularly

With these results, you can end up with an extremely restrictive diet that could risk the development of nutrient deficiencies and decrease your overall quality of life.

The bottom line

Food sensitivities and your symptoms are real, but IgG food sensitivity tests are not. Do yourself a favour and work with a dietitian or an allergist to determine the root cause of your symptoms to save your time, money, well-being and maybe even your life.

About the author — Kristen is a registered dietitian and freelance nutrition writer.

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