Professor Patrick Holford of Teesside University and Head of Science and Education at Biocare is a staunch advocate of direct to consumer IgG food intolerance tests and is impressed by the “sound science” that underlies these tests. Holford is convinced that:
The evidence for IgG antibody reactions as a basis for food intolerances continues to grow, including well designed randomised controlled trials, however, some health professionals just haven’t kept up to date. Perhaps it’s because a ‘home test’ takes the power away from the professional and puts it in your hands.
However, Holford is also swayed by the scientific research for a neck pendant that protects wearers from the evil eye of electromagnetic radiation so one might be tempted to generalise from that as to the scientific credibility of some of his endorsements. It is also indisputable that the expert consensus is that these IgG blood tests are of no value in the diagnosis of food intolerance.
Expert Opinion, the House of Lords and the ASA
Professional organisations throughout the world have issued statements about IgG food intolerance testing that make it clear that:
There is no credible evidence that measuring IgG antibodies is useful for diagnosing food allergy or intolerance, nor that IgG antibodies cause symptoms. [ASCIA]
Clinical allergists and immunologists with impeccable research records and many years of clinical experience have explained that there is no scientific support for the role of IgG testing in the diagnosis of food intolerance. One particularly exasperated expert, the redoutable and remarkably compelling Dr Glenis Scadding, Consultant Allergist at the Royal Nose, Ear and Throat Hospital, characterised IgG tests for food intolerance as “a waste of money”:
What I do dispute is that it is worth making any attempt to identify IgG antibodies. We all make IgG antibodies to food….I see no way in which this can be used to guide diet.
I don’t think there’s any point in spending money on IgG antibody tests. You’re better off going to see a dietitian and using an exclusion diet followed by reintroduction. The IgG antibody tests are liable to leave patients on diets that are inadequate and patients often like to think they’re improving. They carry on in the teeth of very little improvement and may end up malnourished.
I think [self-testing kits] should be banned.
Back in 2006, the House of Lords appointed a committee to investigate allergy and allergic disease in the UK. The Committee investigated some important issues with implications for public health and public policy. They heard extensive evidence on the role of appropriate allergy testing and the lack of scientific support for currently available direct to consumer food intolerance or allergy tests.
Well, it rather seems as if the House of Lords Committee has greater confidence in the undisputed expertise of Scadding and other comparable experts rather than Holford who has no original clinical research or even indexed, peer-reviewed publications in this area. In a comprehensive report HL 166-I (pdf from which pg numbers are given), they make a number of good recommendations and provide some useful summaries. Pages 86-88 cover the issue of direct-to-consumer tests such as the YorkTest foodSCAN IgG test for food intolerance and the YorkTest-Allergy UK MAST IgE test for allergies to food and airborne allergens, amongst others. The committee noted:
Dr. Gill Hart, Technical Director of YorkTest Laboratories, a company which manufactures such tests, told us that the presence of either IgE or IgG antibodies does not necessarily prove whether a food allergy exists, but claimed that IgG could be used “as a marker that a reaction has occurred” (Q 742). However, there is limited evidence to support this claim.
Furthermore, the EAACI even discredited the use of well validated tests based on IgE antibodies if they are used on a self-testing basis. This was because the tests “cannot be interpreted without a detailed clinical history taken by an allergy-trained individual, thus over the counter and postal testing is open to misinterpretation unless expert opinion is available” (p 70)…
Dr Hart admitted that the mechanisms used in the tests were “unclear…”…
Given the lack of evidence for these services we were concerned to learn that Allergy UK recommended the Yorktest service for food intolerance. The charity acknowledged that a patient’s best option would be to consult a dietician, but noted that “being able to obtain a referral to a dietician who understands food intolerance is extremely difficult on the NHS” (p 303).
[Emphasis added.]
One might imagine that the BDA would argue that dietitians have a considerably better knowledge of food intolerance than people who rely upon the results of a test of no proven scientific or clinical efficacy or who find themselves recommending YorkTest on the rather desperate grounds of faute de mieux:
It’s a lack of other places to send these people to. Err, we would give the YorkTest purely because it’s the only one that has undergone trials-particularly for IBS and that’s what we would say, that we would [be] happy to endorse it for, would be for those kind of symptoms. Eh, but, you know, we wouldn’t recommend any other test.
Desperate people searching for solutions do not need to be fobbed off with expensive tests of no proven efficacy in the hope that it will provide a palliative of dubious duration. It is unfortunate that people who are already in distressed circumstances may restrict their social activities because of the perceived difficulty of living with allergies and intolerances that may be inappropriately diagnosed.
Holford Watch is not optimistic that Holford is heeding expert opinion but the House of Lords summed up their advice as follows (pg 87):
We are concerned both that the results of allergy self testing kits available to the public are being interpreted without the advice of appropriately trained healthcare personnel, and that the IgG food antibody test is being used to diagnose food intolerance in the absence of stringent scientific evidence…We urge general practitioners, pharmacists and charities not to endorse the use of these products until conclusive proof of their efficacy has been established.
It almost seems gratuitous to add that the House of Lords aligns themselves with clinical experts in their notion of who is qualified to diagnose allergies and allergic disease (hint, it is not the typical holder of a Diploma ION nor an auto-didact nor self-proclaimed expert; pg 89):
An accurate diagnosis is key to treating an allergic condition adequately, and much depends on taking an accurate patient history with details of a patient’s symptoms, home and occupational environment, temporal and geographic features, relevant family history and any physical signs. Diagnostic tests are often based on skin tests, blood tests and challenge tests. But the results of tests are meaningless in isolation; they have to be interpreted in the context of the patient history, a difficult task which requires a solid training in allergy.
[Emphasis added.]
It is important that an evidence-based approached should be used in the managment of allergies and allergic disease that have the potential to be life-threatening and can have a significant impact on quality of life. It is too common, particularly for parents who are desperate to help distressed children, that desperate people seek private testing that have no scientific or clinical support. Professor Gideon Lack specialises in the allergic mechanisms of asthma in children. He was sufficiently concerned about the importance of appropriate advice and testing that he conducted a survey of the allergy advice parents have received before they attended his paediatric allergy clinic: his findings were both eye-opening and alarming.
We found almost 50% had received alternative health care advice about allergies before coming to see us. I would say that of the children who come to our clinic at least 10% and possibly up to 20% have received unsound advice; these children will face nutritional problems.
The redoutable Dr Scadding may not have achieved her tongue-in-cheek wish that such direct to consumer tests as the ones lauded by Holford should be banned but it is a good sign that the House of Lords report makes such strong recommendations urging charities and responsible professionals not to endorse such tests until there is evidence of clinical efficacy.
The ASA recently reproved YorkTest for inappropriate claims that IgG blood tests are diagnostic of food intolerance.
We concluded that the evidence submitted was not sufficiently robust to prove the efficacy of the tests for diagnosing food allergy or intolerance.
Hidden Food Allergies
Patrick Holford and Dr James Braly have written a book: Hidden Food Allergies: Is What You Eat Making You Ill? The book announces:
One in two people, including up to 70% of the chronically ill, suffers from a hidden food allergy. Are you one of them?
The book is a tour-de-force that links common symptoms to IgG food intolerance and ‘allergies’. The statistics are drawn from opinion surveys and audits of people who have used the blood test: there is no support for these numbers in the general clinical literature.
In our experience, the vast majority of people have no idea their health problems may be related to eating specific foods. Most people’s food allergies are truly hidden from them…
Chances are, however, that food intolerances or allergies are adding to your burden, and in many cases, are prroving to be the main cause of any health problems…We’ll let you know about the amazing scientific advances that mean you can now identify food allergies from a pinprick of blood using a simple home test kit…
What’s more, we’ll explain why you become intolerant to certain foods by revealing the underlying causes of most food allergies, and how to eliminate these causes and thereby reduce your allergic potentil. We’ll explain how to ‘desensitise’ yourself to foods you’re allergic to so you can eat them once more, a process that usually takes just three months.
Some types of allergies, of course, are for life. If you have this kind, you can’t desensitise yourself completely – but you can reduce the severity of your allergic symptoms using natural, drug-free methods, and we will show you a range. [pg. viii-ix]
The book is notable for linking IgG food intolerance (or ‘allergies’) and ‘leaky gut syndrome’: there is no support for such a link in the clinical literature.
It wasn’t until the 1980s that published research began to demonstrate that a fundamental mechanism behind IgG food allergy was the penetration of large molecules of incompletely digested food through a leaky intestinal lining into the blood stream… [pg. 86]
Allergies and leaky gut syndrome is one of those chicken-or-egg situations. There’s good reason to suppose that having a more permeable digestive tract is what precipitates food allergies in the first place, while having a food allergy encourages a leaky gut by inflaming the digestive tract wall. While you can test for increased intestinal permeability, it’s highly likely that you have a degree of increased permeability, especially if you have multiple food allergies or digestive symptoms. [pp. 139-40]
The authors inform the reader that it may take the following tests to identify allergies:
tests exist to identify deficiencies in digestive enzymes, leaky gut syndrome, and the balance of bacteria and yeast in the gut. They can be arranged through nutritionists… [pg. 112]
[To identify your allergies you may need] an IgG food allergy test, a coeliac screening test and possibly an IgE food allergy test. [pg. 126]
The authors advise the extensive use of supplements to heal the gut: they caution that the supplements are necessary to reduce allergic potential and that the benefits of an elimination diet may not be possible if the gut is not ‘healed’ first. There is no clinical support for the gut-healing programme that the authors recommend for these ‘allergies’.
The authors attribute too much significance to the slight findings of the scant research that has been conducted for IgG-led elimination diets and IBS: this research has been discussed elsewhere and does not support the authors’ claims for it (cf, Dr Scadding’s comments above). I
More recently, Holford is impressed by the evidence value of an audit of a customer survey for YorkTest. This is particularly poignant in the light of the testimony of one of the authors, Hart, who admitted that IgG levels do not prove that an intolerance/allergy exists (see above). Hardman and Hart acknowledge the equivocal status of IgG as a marker for food intolerance in the introduction to the paper that gives an account of the customer survey:
the exact role of IgG antibodies as markers of food intolerance in general is not clear. IgG antibodies to food antigens are often present in healthy individuals and are generally considered to be part of the normal immune response to food allergens [refs].
The Hardman and Hart audit does not provide support for the value of IgG tests as a diagnosis of food intolerance: Quote Mining and Misrepresentation: Poor Ways to Claim Clinical Validation or Sound Science; More Allergy and Intolerance Testing Nonsense: Part 1; Food Allergy and Intolerance Tests: YorkTest Gives Evidence to the House of Lords . It is rather unfortunate that even though Hardman and Hart understand this about their paper, Patrick Holford does not.
Conclusion
The expert consensus is that there is no clinical or scientific support for the use of IgG blood tests in the diagnosis of food intolerance.
It is inappropriate that people are led to believe that there are clinically validated blood tests available to diagnose such conditions as food intolerance.
The public understanding of the issues of allergy and allergic disease is confused when issues of intolerance, sensitivity and allergy are discussed as if they are equivalent.
Why does everything have to be explained by science? Science doesn’t have all the answers! I see a lot of people here that are puffed up with their own self-importance and bigger than life egos. It would be nice if you could at least try to understand and acknowledge that people have been helped by this method of allergy testing, and try to look outside of the box. I would appeal to your ignorance and request that you allow yourselves to look at the wider picture and not to dismiss these claims just because it doesn’t fit in with your scientific laws and paradigms.
I note that you’re posting a comment (with no obvious link to the post or broader blog topic) on an anonymous blog – complaining about the egos of people here. Writing anonymous blog posts, closely referenced to the research literature and with no reference to my personal qualifications etc, is not generally how I like to puff up my ego.
For those who are interested in the post topic, there was some interesting discussion of IgG tests on Radio 4′s Case Notes today.
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Well, the research can say what it will but I thank god that I got the IgG testing done. I found out through that that I am highly reactive to all dairy products. After a couple of months of being dairy free I tried to eat some bleu cheese and after about an hour or so my face started to swell and another hour later I was on the toilet. I won’t go into detail :) …I felt awful. The skin prick test came back with nothing. I’m glad I removed dairy. I feel so much better and would never have known without that test.
I am glad that you are feeling better now. However, if you get such a strong reaction to dairy, this would be worth discussing with your GP (and asking for a referral if needed).
Out of curiosity, if you have such a strong, quick reaction to dairy, why was IgG testing needed in order to diagnose this?
My GP is who recommended the ELISA test. She knew that the Allergist I was seeing wasn’t going to solve it. She is an MD and a Homepath. When I went to the Allergist with my ELISA IgG results he threw them back at me and said they were useless. He wanted me to get weekly shots for cat allergies and dust mites etc. I never went back to him.
As for why it took an IgG test to diagnose this? I have no idea. I’m not a doctor. The IgE test showed no problems with dairy but let me tell you if I listened to conventional medicine I would still be where I was and that was not a pretty place. In addition to the IBS symptoms and the angioedema/hives, I also suffered from a severe asthmatic response after consuming large amounts of dairy, was lethargic, and depressed. All that has now changed.
I’m glad you’re feeling better now. However, you can’t tell whether a test works based upon anecdotes. It’s possible that – for example – you really are intolerant to lactose/dairy: this isn’t uncommon, and even a stopped clock is right twice a day.
What about antigliadin IgG as a measurement for Celiac Disease? Should the validity of that test also be suspect?
I have just read this article and comments with interest as I am thinking about getting food intolerance testing done as I like a number of other people here I have a theory that some of my own problems are caused by food intolerance. The point I would like to make is this, that whilst the science behind IgG antibody testing may not be 100% sound, the science behind allot of main stream medical work is not that scientific either. For instance, you go to the doctor and he suspects an under active thyroid so he orders a blood test. The blood test comes back as normal and despite you having the symptoms he tells you that you are fine and there is nothing he can do. The reason, because your blood test result is checked to see whether it is within the limits of 95% of the population, as oppossed to where you body wants to be. You could be just within the range but your body wants to be at other end of the range, hence the symptoms, but you are classed as normal. Is it good science to simply check people against the population and ignore what their body is telling them? From that point of view we could all learn allot from Eastern medicine where they look at the whole body. So before trying to say that one particular test method is not based on good scientific research, perhaps a more general examination of generally excepted test procedures should first be undertaken, because until that is done then the vast majority of accepted medical testing should be held with the same distain as the writer has for IgG antibody testing.
Tests tend to be less than 100%. However, the question is whether IgG testing is clinically useful – I would argue that there’s not convincing evidence that it is.
I took the YorkTest three years ago,
eliminated virtually all the foods with any degree of intolerance.
I have not become seasonably sick with a cold or flu which I have had at least once a year,
every year prior to the test…
I still live and work at the same places prior to the test,
spend the majority of my time with the same
people(who still get sick yearly at least),
and I exercise the same amount.
Where I am going with this?
The only significant change,
that I am aware of is my diet(which was based around the results of the york test).
Please explain to me then,
how there is no connection?
I live in a major metropolitan city and have been exposed to many sick people,
yet its just my good fate to suddenly not get sick…
No connections between IgG testing and allergies and food intolerance’s?
A pure coincidence on the behalf of Yorktest?
No connection, then just blind luck?
I finally won the lottery!
Maybe it is the fallibility of the study’s that you are selectively looking at?
I’m glad you’ve avoided the flu for a couple of years running – but two or three years of no seasonal illness is not exactly proof of anything. Sometimes we’re lucky, sometimes not :)
John,
I am currently 33 years old.
I had been seasonally sick(flu or cold) every year
for the first thirty years of my life WITHOUT FAIL.
The last three years I have not become seasonally sick after following the guidelines of my Yorktest results.
I do not work for Yorktest nor do I benefit in anyway
financially or physically from giving them due credit.
There have been no other major changes besides my diet, that occurred in my life, as I have previously stated.
My wife has been seasonably ill every year of her life, including the past three, where I was not sick.
I live in a major metropolitan city with sick people in close proximity…
Yet you think I am just lucky that I haven’t become sick. 30 YEARS of being sick and suddenly lucky!
There are other people submitting comments about the IgG blood tests having profound results for them as well. You are in denial if you think that there is no connection just cause you selectively picked clinical studies don’t concur!
Your arrogance has probably deterred more than a few people who might have benefited from these tests. I might not feel as good as I do today, if I took your closed minded skeptic advice/view of the world. And this being said by an agnostic and skeptic.
Why don’t you take a poll of those who took the tests,
and then followed the strict dietary restrictions?
Did they or didn’t they benefit?
Instead of citing clinical studies you had nothing to do with…
David – there are all kinds of reasons why people stop getting seasonal illnesses. Some people seem to stop after a certain age, you may be eating a better diet now, you may have excluded something you genuinely were reacting to (even if you excluded lots of foods at random, this would be a possibility) etc. You need good quality research (e.g. a well-designed RCT) to see if a treatment like Yorktest is useful. There isn’t good evidence that it is useful.
I have a big issue with people’s experiences not being validated on here. Clinical trials measure people’s experiences, granted on a larger scale. If it hadn’t been for the ELISA test I would still be waking up in the middle of the night unable to breath and covered in sweat. I would also still be suffering from dermographism and would have diarrhea five times a day. Don’t discredit our experiences. I found out that I am highly reactive to all dairy products. I never knew it until I took the ELISA test and cut everything with any kind of dairy in it. That’s enough evidence for me. Since doing that I have solid stool twice a day, don’t have asthma symptoms anymore, and my hives and angioedema has completely gone. My stomach used to look like I was pregnant I was so bloated which has also disappeared and I have lost ten pounds. Just because you don’t understand how things work doesn’t mean that they aren’t real.
Completely agree with this post.
It WORKED. That is evidence enough for me too.
“Just because you don’t understand how things work doesn’t mean that they aren’t real.”
Great comment.
The original article make’s me wonder if this site is run by some sort of pro-illness, pro-pharmaceutical group.
This article is a joke. I have used Food Intolerance testing and so far, it is the ONLY thing that helped my issues. I could care less about all the horseshit you put up in the page, it’s been over 2 years now, feeling great. Still have some reaction to certain ‘offending’ foods, but I can now eat 4 out of the total 8 again with no problems. I’m all for Science, but Science can be bought and sold. I didn’t have high hopes for this test, but I am very happy with the outcome and could care less what crap you put up here…..just a shame others read it.
I had the york test done 4 years ago, after many visits to my doctor for very painful joints, so bad a specialist told me i had developed arthritus.
after the test showed up an intolerance to eggs, I eliminated them from my diet.
Within a few days my joints started to feel much better, and now they are completely free from pain, unless I eat something that contains eggs and then the pain comes back, for a few days.
Susan – glad you feel better. However, the reason that good research on Yorktest is needed is to test how well it works and to what extent what we are seeing is simply people getting better, the placebo effect, etc…
What a torn faced, obsessed, bitter and rude person you are. The way you reply to people’s calm, composed and well meaning anecdotes about Igg testing diminishes the value of any message you are trying to convey. You just come over as having a hate complex for Patrick Holford. Why can’t you champion something positive. What do you recommend to people who feel food is part of their problem but don’t have true allergies? Let’s here something that isn’t negative in your responses. What’s eating you? Maybe this terse, angry nature you have is being caused by a food intolerance. Why don’t you get it tested?
Positive advice to people who feel food is a problem for them – see a dietitian and/or doctor.
By the way, I find that insulting someone simultaneously with accusing them of being rude tends to be a somewhat self-defeating strategy…
Why does the BSACI tell us to avoid all unproven allergy tests, including IgG (particularly to foods), kinesiology, vega testing and hair and nail analyses.
Why do they say that IgG has no scientific basis for their use. Why do NONE of the NHS Allergy Clinics use IgG. Is their some sort of dark conspiracy between Immunogy Professors in the UK, to hide this amazing test..or is it just that a positive IgG doesn’t mean anything?
An IgG test can tell you your IgG levels. There’s not good evidence that it’s clinically useful – which is why BSACI and others don’t recommend it.
I know 2 people diagnosed with Wheat intolerance via the York test. They removed Wheat from their diet and all the problems went.
I had the same experience with milk and egg intolerance. I removed them both from my diet and the problems I had been having for 10 years – problems about 3 different NS doctors failed to diagnose – dissapeared.
This is obviously anecdotal evidence, and just 3 people rather than a trial of 1000s. You could probably just visit the York website and remove the foods until you found the problem yourself, and save £300.
However it does point people in the right direction, and milk or lactose intolerance is not particularly Holford-like, it’s well established – look at China if you want a large sample of people.
Glad you’re feeling better now. You mention that one could save £300 by eliminating foods and seeing if that helped symptoms. You’re right – a major issue with Yorktest is that there’s not good evidence that it’s better at diagnosing intolerances than a well-designed elimination diet (best to speak to your GP or dietitian about designing such a diet). Absolutely, some people will be lucky enough to hit on foods they’re intolerant to through Yorktest – many won’t, though, and there are better and cheaper ways to deal with intolerances.
By the way, lactose intolerance has a pretty straightforward test – a hydrogen breath test – so there are far better options than Yorktest.
I had been suffering from chronic bloating and gas. I took the IgG test and found out I am highly intolerant to Gluten. Since I have cut out Gluten my bloating and gas has improved tremedously.
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