Food intolerance tests? You’re probably wasting your money

“If you just give me a strand of your hair, I can tell you all the foods that you are sensitive to,” pleads a very enthusiastic shopkeeper, who is at pains for me to fill out a form detailing my food history. He tells me that for just 40 euro, he can detect exactly which foods are causing my “abdominal pain” and “blinding headaches”. He says the results will be available within 5 to 7 days, after which I will have a comprehensive list of fare that I am to avoid.

Another clinic in Limerick claims to be able to reveal all your food intolerances – whether it be an adversity to shellfish or sensitivity to Roquefort cheese – in just under 40 minutes through examination of muscle mechanics. Even to the uninitiated, it is perhaps safe to cast doubt on these dubious testing methods.

However, it is a different type of food intolerance test that is becoming a cause of concern for many experts. The “IgG food intolerance test”  – where blood is drawn in order to be studied for the presence of a specific antibody – has quickly become a staple offering of many pharmacies and clinics dotted around the country. There are as many as six different outlets in the Blanchardstown Shopping Centre selling this test for a substantial sum of money.

Source: Hakan Dahlstrom

And according to experts, these tests are very much in demand. Allergy UK suggests that between 33%-45% of adults now believe they suffer from a food intolerance or allergy. Yet, the Food Standards Agency claim that scientific studies reveal just one percent of adults genuinely suffer from this problem.

Part of the issue can probably be attributed to a general confusion between the terms “allergy” and “intolerance”. The labels are often used interchangeably by testing companies, retailers and even peer-reviewed journals. Dr Clarke, a consultant gastroenterologist at Portiuncula Hospital, Ballinasloe, offers a comprehensive differentiation between the two.

“An allergy is a response by your bodies immune system to a foreign protein which would be termed an antigen that is inappropriate,” he explains. They cause rapid reactions within the body which can sometimes lead to swelling, wheezing, and at worst, anaphylactic shock. Testing for a food allergy is “clear cut”, says Dr Clarke, when a blood test can identify the presence of IgA antibodies. IgA  antibodies are known to relate and be found in the gut when a subject consumes an allergen.

“A food intolerance,” he says, “is a general term that means if you’re exposed to a particular food stuff, you develop what might be a variety of symptoms; discomfort, bloating, increased flatulence.”

Unhappy man
Source: Jim Martin

With the exemption of Celiac disease & other rarer diagnoses, being exposed to a food which you are intolerant of does not necessarily render an immune system response. Therefore, testing for antibodies in this case may prove irrelevant.

Some practitioners claim, however, that it can be performed through use of their specialised IgG blood testing. According to them, if a subject ingests a foodstuff that they are intolerant to, the immunoglobulin type G (IgG) antibody will attach itself to the offending food protein.

However, speaking to the Chicago Tribune, paediatric immunologist Dr Elana Lavine claims that the presence of IgG antibodies haven’t been shown to be legitimate markers for intolerance. In fact, she states that IgG antibodies can act as an indication to the level of consumption of a certain food type. For example, if the subject was a pasta lover and undertook an IgG test, the results may determine that they were perhaps sensitive to gluten.

Dr Clarke echoes Dr Lavine’s declarations, stating that “the relationship between IgG antibodies and food intolerances are unknown and unproven.”

As well as disapproval from medical quarters, many societies and organisations are also dubious as to the validity of these blood tests.

In conversation with registered dietitian Ruth Charles, she directs me to the Irish Food Allergy Network, who, in conjunction with the Irish Association of Allergy and Immunology, recently made clear their stance on IgG blood testing in relation to food intolerance.

Their statement reads that “there is neither a rational scientific basis nor proven role for isolated IgG testing in managing allergies or food intolerances.” The European Academy of Allergy and Clinical Immunology are also in agreement.

Source: Wikipedia

However, scientific evidence hasn’t seemed to deter many retail outlets from profiting off these seemingly dubious tests. I visited two vendors of the IgG test in order to find out more information on their veracity, and to experience the standard of information they would make available to paying customers.

I first frequent Boots, the pharmacy-led health and beauty retailer. I speak with a pharmacist who explains to me that they do not carry out analysis of the IgG test on site. Rather, they send it to an external laboratory called the Fitzwilliam FoodTEST, located in Dublin’s city centre. She assures me that the test is in fact valid, and that I should get my results within 7-10 days. The prices start at 150 euro, but I am advised to go for a more expensive test that provides an analysis of a wider range of foods.

I then present myself at McCabes’ Pharmacy. On learning that their pharmacist is on their day off, I ask to speak to another senior member of staff. He provides me with little information, however, he does tell me that they use the York Test laboratory for test analyses. He declines to tell me the price of the test. However upon inspection of the York Test website, a full Food Scan Programme – which tests for 113 foods – retails at 250 euro.

During my research I am also recommended to get in contact with another laboratory called the Clontarf Clinic. They purport to be essentially “gimmick-free”, brandishing their website with tag-lines such as “no VEGA”, “No holistic”, and “no acupuncture offered here!”. However, I am denied a conversation with their house consultant unless I am willing to pay an initial consultation fee which ranges between 150-200 euro. On my speculating their method of food intolerance testing, they only tell me that there are “positives and negatives” to the particular test.

On the many outlets offering these particular IgG tests, Dr Clarke insists that “one has to be careful that you’re not paying a substantial sum of money for information that, while is true – they are detecting a particular antibody to a certain substance – the relationship between the presence of the antibody and the symptoms you may have is not clear.”

Source: pixabay

So, how can reputable retailers and laboratories offer such tests without fear of penalisation?

Dr Clarke reveals that these tests and their provision are “not subject to regulation in the same way that pharmaceutical products or medical devices are.” He explains that the situation is comparable to that of food supplements, which also go unregulated.

“If you bring out a medical appliance,” says Dr Clarke, “you need to supply the relevant regulatory bodies with evidence that your product worked, and was safe and effective. But, in the case of [these tests] you do not have to do that. They’re not regulated in the same way as a medical device.”

“I could bring out a food supplement that was designed by myself and say that it was excellent for people with Crohns disease, and that I’m a very experienced gastroenterologist. And because it’s not a pharmaceutical product there’d be nothing to stop me from selling it. If someone reported me to the Medical Council, and even if I was struck off, they still couldn’t stop me from selling that product,” he reveals.

Dr Clarke also states that the recent popularity of these tests could perhaps be attributed to conventional medicine’s failings. “I think that people are often not getting the answers they need from the conventional approach; these are tests that they can access in pharmacies and they convince people that they are valid and useful.”

He goes on to reveal that, in Ireland, professional guidelines dictate that people must be referred to a gastroenterologist or immunologist by either a GP or another doctor.  Patients will therefore also incur the cost of a GP visit. If someone does not have a medical card, those costs can build up quite rapidly. According to Dr Clarke, Ireland is under-resourced in terms of the total number of gastroenterologists and in equipment for detecting certain food intolerances.

Source: pixabay

“In my own particular unit we had equipment that measured acidity in the gullet but it broke down and reached the end of its service life. The management decided that they didn’t want to fund a replacement because it isn’t a priority area, like cancer and disability are. So, this is a service that’s gone, and it’s no wonder that people who can’t get an answer from conventional medicine turn to alternative practices,” he says.

However, although there have been no reports alluding to danger or harm, the outcome of IgG tests nearly always result in subjects eliminating whole food groups. This restriction, coupled with a loss of time and a substantial amount of money, perhaps calls up the need for tighter regulation in Ireland.

However, until there is a significant amount of money pumped into the areas of gastroenterology and immunology, it seems that these tests will trump waiting in line at a packed doctor’s office.


  1. I recently had the Fitzwilliam FOODTEST. I will admit it was damn expensive, I went for the 60 food test. I had been eating very well beforehand. I was feeling constantly tired, bloated, mood swings and my skin was going crazy. The test showed that I was intolerant to nuts, rice, oats and a few other things that were a part of my diet. I still eat very well now minus those foods and I have noticed quite a big difference in my energy levels, mood, skin, bloating has stopped and my face isn’t as puffy. I feel like most things, people jump onto a bandwagon and don’t put much research into what they are looking for, allowing some companies to exploit those that are credible. But I don’t see what is wrong with people looking for alternatives to going to the doctors for a referral. Because that path most likely would not have them cutting out particular foods but buying medication that they could avoid taking.

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