Are food sensitivity tests really necessary? Here’s what experts say
Calgary-native Chelsea McBroom started to feel “off” in 2012 when she was working at a service camp out on an Alberta oil rig. The 32-year-old said she started to feel sick and experienced weird skin reactions while living off a diet that consisted mostly of processed and packaged food — meals her employer provided to staff.
“It didn’t help that I was working 21 days in a row, [for] 10-12 hours a day,” McBroom said to Global News.
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McBroom went to a doctor with her health concerns, who ended up giving her some antibiotics. After she took them, she still didn’t feel right. Running out of options, McBroom went to a naturopath in Calgary who suggested she take a $500 food intolerance/sensitivity test.
The graphed results, processed by Rocky Mountain Analytical, showed that her body was “moderately or highly reactive” to foods including dairy, whey, eggs, almonds, pecans, beans and casein. McBroom said she was told to only consider eliminating foods that reached into the test results’ third column, the cut-off marker for intolerance.
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“If it reaches past that third column, I have a ‘high sensitivity,’ [but] it doesn’t mean it’s an allergy,” she recalled the naturopath telling her. “I looked at [the results] and decided to avoid eating straight-up egg, whey and almonds.”
McBroom is one of the many Canadians who has taken a food intolerance test and modified their diet in an attempt to treat a range of generic symptoms including headaches, upset stomach, fatigue, bloating and skin irritation. But according to health experts, food sensitivity tests are not scientifically sound, and in fact, dramatically altering your diet can make you feel worse.
What is IgG and how do food sensitivity tests work?
A food sensitivity test is also known as an immunoglobulin G (IgG) blood test, and it’s meant to identify what food intolerances or allergies a person has. IgG tests are sometimes ordered by naturopaths, and they’re offered by major labs in Canada including Dynacare and LifeLabs.
They’re not covered by governmental health plans, and people often pay anywhere between $100 to $500 out of pocket for them.
“What happens at the laboratory level is that they measure the patient’s IgG level to different foods,” explained Dr. Harold Kim, the president of the Canadian Society of Allergy and Clinical Immunology (CSACI). “They typically perform the test on dozens and sometimes even hundreds of foods, and they charge the patients privately for the tests.”
IgG is a type of antibody, and food sensitivity tests claim that by removing foods with high IgG levels from your diet, you can help alleviate your symptoms.
Kim said that the problem with testing for IgG levels is that they do not actually reflect food intolerance. The CSACI has called IgG tests “unvalidated” forms of testing, and said “there is no body of research that supports the use of this test to diagnose adverse reactions to food or to predict future adverse reactions.”‘
In other words, they’re pretty much useless.
In fact, Kim said that varying IgG levels in the body are normal, and are a regular immune response to eating food. So if your food sensitivity test shows a high level of IgG for broccoli, for example, all it likely means is that you ate it recently.
Why are food intolerance tests so popular?
If IgG testing doesn’t actually indicate food sensitivities, why are so many people turning to them for health advice?
According to Dr. Adelle Atkinson, a clinical immunologist at the Hospital for Sick Children and an associate professor of pediatrics at the University of Toronto, people want answers when they experience health symptoms without a defined cause, and food testing seemingly offers that.
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“A lot of people have reactions to food, and many reactions to foods are not allergies,” she said to Global News.
“People might feel like, ‘When I eat that food, I get bloated,’… and when we test them and say, ‘You’re not allergic to the food. You’re not going to have hives and swelling when you eat it, but I’m sorry I can’t explain why you feel bloated,’ … they go searching for answers.”
Atkinson says she understands that it’s frustrating for patients when they can’t get deeper explanations from their doctors as to why they feel a certain way, but she worries that food sensitivity tests can push people too far.
“Sometimes, they come back with lists — long lists — of foods that they should be avoiding, some of which are essential foods,” she said. “These [IgG tests] do cause patients to make decisions that are probably not in the best interest of their ongoing health.”
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Seven years later, McBroom acknowledges that her food sensitivity test may not have been completely valid, and that her lifestyle may have contributed to her health issues. “It’s possible the naturopath I went to took advantage of my situation,” she said.
But even though McBroom says she no longer fully follows the results of her IgG test, she still stays clear of some foods that appeared on her list.
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“I never eat eggs for breakfast or anything, but I eat baked goods and things made with egg,” she said.
“[The test] caused me to question what I was eating and make more educated choices. So even if it’s not totally reliable, I don’t regret it. I’m more in tune to what makes me feel good and what doesn’t.”
IgG testing can be dangerous
Atkinson said that if people are concerned that they may have an allergy, they should keep a food diary of what they ate and their associated symptoms, and seek medical advice from a doctor before relying on an IgG test.
“I always feel so bad for the patients who pay so much for these tests that essentially don’t reflect anything,” she said.
By seeking advice from health-care professionals, patients can ensure they aren’t taking away important foods from their diet, like whole grains and certain vegetables, for example. Plus, allergy specialists can perform specific tests that will reveal a legitimate reaction.
Kim echoes this stance. He said he’s seen patients who have IgG test results that showed they are not allergic to certain things, when it turned out they actually were. This can be deadly, he said, if the food allergy is severe.
“If the patient sees the IgG test and it says it’s negative for peanut, but then that person is really allergic to peanut, then there’s a real danger,” he said. “I’ve had a number of those patients over the years where thankfully, they come to me for reassessment before trying the food.”
“It could potentially be really dangerous.”
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