Category Archives: intolerance

Patrick Holford, YorkTest and a Migraine Study

Former Visiting Professor Patrick Holford but still Head of Science and Education at Biocare has an enthusiasm for interventions that we wish we might share but, too frequently, when we examine the studies on which he relies, the results do not support his claims or the scope of his optimism.

In a recent newsletter, Patrick Holford was rather excited about a recent study: Randomised controlled trial of food elimination diet based on IgG antibodies for the prevention of migraine like headaches. For reasons that may become clear, he neglected to mention the full title of the paper.

Last month a study published in the Nutrition Journal showed that 85% of people affected by debilitating migraines had their symptoms reduced, and quality of life improved, when their food triggers were discovered and avoided. Having a hidden food allergy is one of five common causes of migraines.

This recent study tested migraine sufferers for food allergy using YorkTest’s FoodScan test. Eighty four of the volunteers were put on their food allergy free diet, while 83 were given a sham ‘allergy’ diet based on fake test results. At the end of four weeks those on the real allergy free diets had had 23% less migraines than those on the sham diet.

You might be a little surprised that Holford was quite so excited by this result after 4 weeks of assessment that the newsletter was subject-lined, “Relieve your migraine without painkillers” and headlined, “What’s causing migraines?”. Holfordwatch consulted the original study and can not agree that Holford provides a useful interpretation of its outcome.[1] According to the reported results, it seems as if even the study’s authors might quibble with Holford’s optimism:

The results indicated a small decrease in the number of migraine like headaches over 12 weeks, although this difference was not statistically significant (IRR 1.15 95% CI 0.94 to 1.41, p = 0.18). At the 4 week assessment, use of the ELISA test with subsequent diet elimination advice significantly reduced the number of migraine like headaches (IRR 1.23 95%CI 1.01 to 1.50, p = 0.04). The disability and impact on daily life of migraines were not significantly different between the true and sham diet groups. [Emphasis added.]

There are many other problems with this paper (eg, the participants are effectively self-selected from a group that is pre-disposed to believe that food intolerance influences migraine; there is no clinical verification of the migraine-like headaches description; respected experts in allergy and immunology caution against the notion that Yorktest’s IgG Food Intolerance test is diagnostic of food intolerance or clinically relevant; the number of study drop-outs compromises the power of the study effect). The study lacks scientific rigour to the extent that the only surprise is that a journal reviewer changed his opinion between 1st and 2nd review:

This paper has strong deficiencies in respect to the study design, recruitment, compliance, and no medical control and assessment of the subjects, not meeting the criteria for a scientific paper. Due to the huge amount of uncertainties, also acknowledged by the authors, this paper has no new information to offer and is of limited interest.
Level of interest: Reject as not of sufficient priority to merit publishing in this journal. [1st review]

Such flaws in the design and other areas can not be corrected merely by re-writing yet the reviewer accepts the revisions (eg, the revised title now refers to “migraine-like headaches” rather than “migraine”) and changes the review comment to:

Level of interest: An article whose findings are important to those with closely related research interests. [2nd review]

Recall that the research finding is not, as Holford leads, “[You can relieve] your migraine without painkillers” but that the study revealed that at 12 weeks (the study’s stated primary outcome): “this difference was not statistically significant“. Holford’s account is partial and inaccurate. This is lamentable when one considers that he claims to be a valuable intermediary between the public and the practical reporting of health research. It is unsettling when one considers that there is considerable apprehension that some patients and healthcare providers might be persuaded by such claims to lobby for such ineffective tests and diets to be funded by the NHS despite their lack of clinical relevance or efficacy.


[1] Holfordwatch notes that Yorktest provided a similarly partial account of the study findings in their September 2011 news items and that the media that ran the Yorktest release on this study did not investigate the findings but reproduced this and other unduly favourable interpretations (the rollcall of shame includes: Metro, Red Online, Top Sante, Women’s Fitness, Women’s Weekly, OK Magazine, Woman’s Weekly, Female First.

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Filed under food intolerance, IgG tests, intolerance, patrick holford, yorktest

Holford gives poor advice about dietary restrictions for children. Again

Last year, Food for the Brain modified some advice on dietary exclusions for children – when we pointed out that such changes should be implemented under medical and/or dietetic supervision. We were therefore disappointed to see iAfrica reporting Holford’s advice that “in order to maximise your children’s potential” you should:

Take your child off foods with additives or added sugar [and] Eliminate allergens from the diet…If you suspect your child is intolerant to a particular food, eliminate it from their diet and monitor the difference/reaction. If after two weeks if you see no difference in the behaviour or symptoms, reintroduce it and see if there’s a reaction. The most common foods that cause problems are wheat, gluten (the protein found in wheat, barley, rye and to a lesser extent oats), diary foods and eggs.

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Filed under allergies, elimination diets, Food for the brain, Food for the brain foundation, intolerance, patrick holford

Dr John Briffa on testing for food sensitivity: applied kinesiology, dowsing and IgG tests

JDC reports that he “always thought that Dr John Briffa was like a more grown-up version of Patrick Holford” – and until recently I had rather agreed with him. However, Briffa has now taken up some worrying positions on vaccines and autism. Along with Dr Crippen, “I am worried about Dr John Briffa.” Continue reading


Filed under allergy, IgG tests, intolerance, patrick holford

Food for the Brain: Child Survey: Review Part 2

Professor Patrick Holford of Teesside University (and also Head of Science and Education at Biocare) and Drew Fobbester are joint researchers and authors of the Food for the Brain Child Survey, September 2007 (pdf). This is the second of three Holford Watch posts in which we explain why the literature overview in the FFTB Child Survey is inadequate: some of the claims made in the review are not supported by relevant references or studies of sufficient quality. Part 1 discussed the claims relating to supplements and children’s diet. Part 2 examines the claims made for the benefit of a balanced glycaemic load diet for children.
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Filed under children, Food for the brain, Food for the brain foundation, food intolerance, food sensitivity, gluten intolerance, glycaemic load, glycemic load, Holford, intelligence, intolerance, nutrition, patrick holford, referenciness, truthiness

Patrick Holford, IgG Food Intolerance Self-Testing and the House of Lords

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. Continue reading


Filed under Electromagnetic Radiation, EMR, food intolerance, Holford, home test, IgG tests, intolerance, patrick holford

Update on Food for the Brain’s Evidence for Allergy and Intolerance Testing in Children

On May 1 I wrote up my attempt to discover Food for the Brain‘s evidence for allergy and intolerance testing in children. Today, May 10, I noticed that Food for the Brain (FFTB) has removed the evidence and search facility that I criticised and withdrawn access to the summaries of the papers that they cited in support of some of their claims and recommendations (as addressed in my original piece).

My original search for FFTB’s evidence behind their recommendations for allergy and intolerance testing was an unsatisfactory experience and I expressed myself at some length on the matter.

I have no idea what the search engine algorithm on that site was doing but I doubt that I could have had less relevant or helpful ‘answers’ if I had been sticking my hand in some truthiness and referenciness tombola and pulling out solutions.

I have several concerns about the quality of FFTB’s evidence for some of their recommendations.

Following FFTB’s recommendations for allergies and intolerances may have substantial financial and social implications for a family and the way in which they accommodate the needs of family members. It would probably be very helpful for parents who are interested in exploring some of FFTB’s recommendations for their children if FFTB explained some of their recommendations more fully and provided references to the scientific literature that directly support those recommendations.

Today, May 10, I learned that FFTB has withdrawn the evidence and search facility. The page now carries the forlorn notice:

Please accept our apologies but this part of the site is under re-construction at present. We hope to have the research and search database facility back on-line in July this year.

Thank you for your patience and your continued support.

Further than that, FFTB has also withdrawn the summaries of the papers that they provided to support their claims and recommendations.

FFTB offers a range of special reports (authors not identified):

From in-depth articles on autism to the latest clinical approach to schizophrenia, here you will find detailed information on the link between nutrition and mental health.

Unfortunately, you can’t see the reports unless you pay to subscribe to FFTB. Based on what I’ve seen of the relevance, research and writing quality of the FFTB site, I’m reluctant to part with the money to see the reports although I would gladly accept some review copies on relevant topics. E.g., I would very much like to see: Autism and a gluten-free, casein free diet – is this an appropriate dietary intervention and what is the rationale behind this approach; Oxidative Stress in Autism; Final Report on Food for the Brain’s School Project at Cricket Green.

Although I do not know why FFTB has chosen to reconstruct the evidence and search section, nor why they have withdrawn access to their summaries of the research papers, I am pleased that they are revising these sections. I hope that their future evidence will be fully referenced and more relevant to the parents who are consulting it.


Filed under allergies, allergy, Food for the brain foundation, intolerance, patrick holford

Food For The Brain modify their website, in response to Holford Watch criticisms

I’ve previously argued that some of the advice on Food For The Brain’s website was potentially dangerous. The website previously advised that autistic children “remove…likely culprit foods such as wheat and dairy from the diet [and] avoid additives and preservatives.” However, the website did not advise parents to seek medical supervision when excluding large numbers of foods from their childrens’ diets; it also didn’t mention the need to find appropriate replacements for the foods which are excluded.

Happily, Food for the Brain have taken my advice on board. This section of their revised ‘action plan’ for autism now reads “consider pursuing a wheat and dairy free diet which has proven helpful for some, but not all, autistic children. However we recommend you do so under medical supervision, or supervision of a dietician or nutritional therapist to ensure that suitable replacement foods are included that ensure your child achieves optimal nutrition.”

While I haven’t had time to read this page in detail this is clearly a significant improvement. It’s great to see that Food For The Brain is taking Holford Watch’s advice on board!


Filed under allergies, autism, dairy, Food for the brain foundation, gluten intolerance, Holford Watch successes, intolerance, wheat

Patrick Holford confuses allergies and food intolerances. Again. And tries to flog unsuitable tests. Again.

Got another Holford e-mail (through his mailing list) on April 5 – this time, talking about hayfever and allergic reactions. Holford advises that readers

-Avoid mucus-forming, pro-inflammatory foods such as dairy products and meat.
-Further reduce your allergic potential by avoiding highly allergenic foods such as wheat, gluten (rich in wheat, rye and barley) and yeast.
-Get tested for food allergies so that you know if there are any other foods you need to avoid. And sort out any digestive problems. Disruption in the gut enhances allergic potential.

Unsurprisingly, the tests that Holford recommends are the same IgG and IgAtTG tests that he has advertised before, and that he sells.

– Firstly, IgG tests for food intolerance do not reliably diagnose food intolerance, even when used ‘correctly’.
– Secondly, at best these tests can measure whether one has reacted to a certain food. Therefore, if readers follow Holford’s advice – cut out whole food groups and then, a while later, get an IgG blood test – there’s about a snowball’s chance in hell of the tests diagnosing any intolerances to these foods, even if the test subject is intolerant.
– Thirdly, the tests Holford sells only try to find IgG/IgAtTG reactions. Other reactions (e.g. IgE-mediated reactions) may not be found.

Once again, Holford seems to be conflating allergy and intolerance. Again, he gives inappropriate advice on diagnosing allergies and intolerance. And, once again, he happens to sell the ‘diagnostic’ tools that he’s promoting.

Anyway, this repetition must be getting a bit tedious. If Patrick Holford keeps repeating the same bad advice, though, I feel kind-of obliged to keep repeating the same kind of criticisms. Sorry.


Filed under allergies, allergy, Coeliac Disease, gluten intolerance, hayfever, IgAtTG, IgG tests, intolerance, patrick holford

Running out of tolerance: allergy, intolerance and Coeliac Disease

In an Independent article, Holford appears to confuse wheat allergy and gluten intolerance. On March 30, his 100% Health e-mail newsletter asked “Could gluten be undermining your health?” However he seems, again, to have conflated allergy and intolerance.

Holford begins the e-mail by saying that “Gluten allergy – or coeliac disease – used to be considered a rare condition, but new research suggests that 1 in 100 may be affected”.

The Food Standards Agency (FSA) has a nice clear account of the difference between food allergy and intolerance:

Food allergy and food intolerance are both types of food sensitivity. When someone has a food allergy, their immune system reacts to a particular food as if it isn’t safe. If someone has a severe food allergy, this can cause a life-threatening reaction.

Holford usually claims some significance (not supported by expert opinion) for IgG levels as diagnostic of food intolerance; however, one thing on which most people agree is that this sort of food intolerance doesn’t involve the IgE immune system and is generally not life-threatening. But if someone eats a food they are intolerant to, this could make them feel ill or affect their long-term health.

Coeliac disease can be wretchedly debilitating – the symptoms from this can be horrible. However, unlike an IgE-mediated allergic reaction, diagnosed and managed coeliac disease is unlikely to cause a sudden-onset of life-threatening problems. Coeliac Disease provokes a non-IgE mediated reaction brought about in genetically susceptible individuals by exposure to the gluten in wheat and other cereal grains; it functions through a different mechanism to an IgE wheat allergy. It’s therefore important to distinguish between the usual sort of wheat allergy and intolerance that Holford usually conflates and Coeliac Disease – but Holford often fails to do this.

The FSA is right to say that “[i]f you think you have a food allergy or intolerance, then it’s important to get a proper diagnosis.” However, in the 100% Health e-mail Holford suggests hometesting for IgAtTG – by a wonderful coincidence, Holford’s Health Products for Life sells such tests.

Looking on pubmed, IgAtTG was formerly recommended for checking that coeliac patients have been sticking to their gluten-free diet. More recently, Biocard has been promoted as a form of rapid-testing for Coeliac Disease; however, although these tests have been validated, and are comparatively easy for an expert to interpret, it is not necessarily straightforward for the general consumer (see also, Update 2). It is possible for a test to have very high specificity and sensitivity when used by appropriately trained and experienced personnel but to have very different accuracy when used by the general consumer who is (presumably) seeing and using the test for the first time.

However, Holford markets this test as reliable for home use and tacks between discussions of wheat allergy, intolerance and Coeliac Disease, conflating IgG and IgE mechanisms and sometimes equating this conditions. It is vitally important to distinguish these because they have very different implications for quality of life; [update, April] as pointed out in our comments, people with Coeliac Disease qualify for financial support and prescriptions to defray the costs of what would otherwise be very expensive diet. They also qualify for expert guidance from dietitians.

The only article Holford mentions* as support for his marketing is an article I haven’t been able to find in pubmed, or in the referenced journal’s table of contents.

Holford also notes that testing for IgAtTG will ‘diagnose’ celiac disease in a surprising number of people:

[t]he old view was that about 1 in 5,000 people had coeliac disease, the genetically transferred digestive and malnutrition disorder caused by an extreme allergy to gluten. However, new research shows that gluten allergy affects possibly as many as 1 in 100 normal, symptom-free people, often showing no digestive symptoms at all

This is an on-going debate among researchers who have dedicated their work to this topic. If a new, relatively unvalidated as a direct-to-consumer test ‘diagnoses’ a disease in apparently healthy people, the first ‘obvious’ question is whether the test is generating false positives. A second obvious question is – if the ‘disease’ isn’t causing any ill health – whether there’s any reason to modify one’s diet (there may be) and if there are any consequences to transforming someone into a potentially ill person. As explained on the wonderful BreathSpa blog, even if a reliable test shows “sensitisation” to a substance, if this is not causing any problems then this sensitisation may “not [be] clinical disease”, and it might be inappropriate to treat it as such. The consultant allergist Dr Scadding goes on to argue that:

you can not have self-testing kits: they’re going to lead to mis-diagnosis, mis-allergen avoidance. You need both the test and a detailed history taken by somebody who has some experience of allergy history taking and interpretation of tests.

To summarise, then, Holford makes the dangerous mistake of conflating wheat allergy and gluten intolerance. He also advocates – and sells – what he calls “gluten allergy” testing kits. Holford is promoting these these kits as diagnostic of Coedliac disease and what he styles as gluten intolerance; however, looking at the peer-reviewed medical literature, I can’t find convincing evidence that they actually work for intolerance in the sense that Holford typically uses this term. The final nail in this proverbial coffin is that – even if these tests did work (and they are part of the portfolio for managing Coeliac Disease) – it’s unlikely that home testing would be appropriate. For Coeliac Disease, you need a qualified gastroenterologist or similar to take a case history, and to interpret whether or not the presence of IgAtTG antibodies in the blood does show the presence of a clinical condition (which requires treatment with gluten-free diet etc.). Following such tests, you may need to confirm the diagnosis with an endoscopy and/or biopsy.

Neither Coeliac disease, nor wheat allergy, are trivial matters. They need to be diagnosed and treated properly, not using an home test that may be inappropriate for direct-to-consumer use – sold by a nutritional ‘expert’ who fails even to distinguish wheat allergies and intolerances or Coeliac Disease.

Update 4 Jan 2008: Coeliac UK expresses caution about these home tests.

While we welcome a new tool that could help to get more people diagnosed we would stress that blood tests for coeliac disease are not 100% accurate and there are individuals who may have false negative results – even if they have not changed their diet. The self-testing kits should not replace a medical diagnosis and we recommend that if anyone has symptoms of coeliac disease they should go to their GP. [Coeliac UK goes into more detail (pdf).]

Update 2 16 Jan: There may be a role for such rapid test facilities for Coeliac Disease when used by a GP or Practice Nurse (Medscape; free on registration). However, a recent study of population screening for Coeliac Disease among 6-year-olds is a useful illustration that the specificity and sensitivity of a test may change, depending on who is interpreting the results. E.g., in this study District Nurses (the majority of whom had received some basic level of training) performed the rapid testing with the same test that Holford promotes, and yielded a disappointing 78.1% sensitivity but excellent specificity of 100%.

The rapid test seemed to be as accurate as laboratory testing and had a high positive predictive value and specificity. Some training is needed, however, to enable faint test lines to be recognised when circulating antibody concentrations are low. As with all visual tests, observer variability can affect the results, so the diagnosis should always be verified by histology.

It is for these reasons that Holford Watch questions whether it is truly ’empowering’ for consumers to be persuaded to pay for a test that they may not be able to interpret correctly and would need further validation from a GP.

There is an interesting discussion to be had about the cost-benefit to the individual and society of mass-screening for Coeliac Disease. There is undoubtedly a need for more education and awareness of Coeliac Disease; however, this discussion is hampered when self-styled experts confuse the matter for the general public by conflating Coeliac Disease with IgE food allergies or so-called IgG food allergy/intolerance.


*Gerarduzzi T et al. Celiac disease in USA among risk groups and general population in USA. Journal of Pediatric Gastroenterology and Nutrition. Vol 31 (suppl) 2000: pp S29, Abst 104. [Having searched Jnl of Ped Gastro and Nutr, this paper doesn’t seem to exist as per this reference. It appears in Google Scholar as a citation only which might indicate an error.]


Filed under allergies, Coeliac Disease, gluten intolerance, hometesting, intolerance, patrick holford, wheat allergy

What not to believe? Independent relies on Holford’s advice for article on good diet

Yesterday’s Independent carried an article on ‘What Not To Eat’. A large part of the article was based on Holford’s recommendations, and there are a number of problems with the article. I’ll list a few of them below, but the first thing to note is that readers might want to e-mail a letter to the Independent editor – to let them know what you think of the article.

I don’t have time to list all the problems with the article here (it’s sunny outside again, and I don’t want to be spending too long blogging). Here’s a few that stand out, though:
– The article describes Holford as a ‘nutritionist’, but doesn’t make clear that this isn’t a protected title in the UK: anyone can call themselves a nutritionist. Holford is able to call himself a nutritionist despite lacking any accredited university degrees in this area (his only accredited degree is a BSc in Experimental Psychology).
It’s easy to become a ‘qualified nutritionist’, too. For one day only, I’m offering a DipHWNut: buy me a pint, and I’ll confer on you, too, this super-relevant qualification that lets you call yourself a qualified nutritionist. Fame and fortune awaits!
– Holford claims to be “a vegan who eats eggs and fish”. That is what us non-experts call ‘not a vegan’: a vegan is someone who “does not consume or use animal products“. I’m not saying that people shouldn’t eat animal products – I do this myself – but don’t call yourself a vegan if you do.
– Holford appears to make the basic error of confusing food allergies and intolerances. He claims that wheat is one of “the two most common food allergens“; however, the Food Standards Agency describes wheat allergy as “not very common in the UK“. Wheat intolerance is more common, but is quite different from an allergy. It’s very important to distinguish between the two, especially if practicing as a nutritionist.
Anyway, the fact that gluten intolerance is relatively common does not mean that those of us who are not allergic to or intolerant of wheat should stop enjoying wheat products. Good bread is a real pleasure, and a nice British tradition – it’d be tragic to lose this based on dodgy nutritional advice.
– Holford argues that sunflower oil is one of the best types of fat for vegetarians to eat, but this oil is high in omega 6 fats. It seems that eating a relatively high ratio of omega 3 fats to omega 6 fats is beneficial (pdf). Foods rich in omega 6 fats – such as sunflower oil – should therefore be enjoyed in moderation, and not be used as a major part of one’s fat intake*.

Some people may need specialised nutritional advice – they’d do well to see someone who knows what they’re talking about (e.g. a qualified dietician). After all, cutting out large numbers of foods from your diet (e.g. Holford appears to advise avoiding wheat and dairy) without good reason can be unhealthy.

Look – for most people, good nutrition is largely commonsense. As Ben Goldacre likes to say, ‘eat your greens‘. We don’t need self-proclaimed nutritional experts to tell us ‘what not to eat’. We just need our own common sense to tell us what healthy foods we should be enjoying, and which foods are best enjoyed only in moderation.


*research in this area is ongoing, and in my understanding is not yet conclusive. However, I still would not view eating lots of omega 6 fats as good nutritional advice.

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Filed under allergy, Ben Goldacre, dairy, Independent, intolerance, nutritionists, patrick holford, qualifications, wheat