Category Archives: food 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.

Notes

[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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Anton Emmanuel on why IgG testing for intolerances is not a useful diagnostic tool

Dr Anton Emmanuel is a Senior Lecturer in Gastroenterology at UCL. He has also studied the use of IgG testing kits – specifically, Yorktest testing kits. His research has been referred to (very likely inappropriately) by Yorktest in defence of their products. He is also one of the experts listed as backing Food Intolerance Awareness – which refers people to Yorktest for IgG tests.

When Radio 4’s Case Notes investigated food intolerance, Emmanuel was interviewed re IgG testing. We were surprised to hear him offering a rather (in our opinion, appropriately) negative assessment of the diagnostic value of such tests for identifying food intolerances.

Emmanuel is introduced by the presenter as not being very impressed with testing kits, and describes this process of testing as “not nearly as specific as one would like it to be”. For Emmanuel, the fact that wheat, yeast etc. come up often on these tests probably reflects “as much as anything else, our exposure to these things in our diet” rather than a specific intolerance/allergy.

Emmanuel is not impressed with these tests due to, among other issues:

  • No external standard as to levels which show intolerance: the tests rely on internal standards which aren’t as robust as one might like.
  • The effects in the patients Emmanuel has seen using these tests have largely been unimpressive, period. Even where patients did appear to benefit, results have not been great in the longer term.
  • A slightly leaky gut may lead to an IgG response to various proteins. It is erroneous to tie this response to specific proteins.

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Allergy UK Wants YorkTest IgG Food Intolerance Tests Available on NHS

I am constantly in awe of the resilience of people and companies: their nonsense can be exposed in the most public of fora and yet they bounce right back with their marketing message unchanged or tactfully edited but still ignoring the point that it is underpinned by nonsense. Former Visiting Professor Patrick Holford comes to mind as does Nas Amir Ahmadi of Detox in a Box. YorkTest (so beloved of Patrick Holford, Allergy UK, and a slew of self-declared experts as well as TV doctors) is another such company. YorkTest offers a food intolerance product that has been declared irrelevant by clinical allergists and immunologists and publicly deprecated but manages to garner pages of laudatory press coverage through its attractive press releases and to win customers because it ‘sounds science-y’. Recently, YorkTest piggybacks onto Allergy UK‘s Blossom Awareness Week to highlight the issue of allergies in children. Continue reading

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Patrick Holford, Still Claiming IgG Levels Are Relevant to Food Intolerance and Weight Loss

Patrick Holford on ITV Lunchtime 16 April 2008
Former Visiting Professor Patrick Holford Head of Science and Education at Biocare so, presumably, they believe that he has scientific credibility and they persist in this belief despite the stack of evidence that might prompt them to revise their estimation of his scholarship, his level of discourse or hyperbolic styling as a in the field of health and nutrition. Holford is particularly obdurate on the topic of IgG tests for the diagnosis of food intolerance. Dr Robert Burton would probably find Holford’s continuing enthusiasm an interesting case-study for the next edition of Believing You Are Right Even When You’re Not. However, it may be understandable that Holford cleaves to this despite the explicit advice from actual immunologists and allergy researchers and clinicians because it makes up part of the platform that allows him to sell tests, pills and special diets that are guided by his books. Continue reading

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You and Yours on Which? Investigation into Food Intolerance Tests

Listen again while you can: BBC Radio 4’s You and Yours on Which?‘s Investigation into Food Intolerance Testing with participation from Dr Mike Walker of Cambridge Nutritional Sciences Ltd.

One note that should be of particular interest to Patrick Holford, given his claims for IgG testing in the diagnosis of food intolerance, is a significant change in stance by the companies who promote, distribute and carry out such tests. We shall write more about this at a later date but Walker was at pains to stress that the Cambridge Nutritional Sciences’ IgG test is indicative of food intolerance but not diagnostic of food intolerance. The tap-dancing on this point was painful and brought a similar episode to mind involving Patrick Holford and his qualifications. Continue reading

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Update on Which?, YorkTest and Selective Quoting in Google Sponsored Links

YorkTest claims that Which? describes IgG as "validated scientific test"
Today’s Google is remarkably free of YorkTest sponsored links such as the one that we highlighted in our discussion of Which?, YorkTest and Cambridge Nutritional Sciences. The Google ad claimed: “Which? Magazine Report Says “Validated Scientific Test”” which is as blatant an example of quote mining as most people will ever encounter. The sponsored links have switched back to highlighting “Endorsed by Allergy UK”. Continue reading

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YorkTest, Hardman & Hart: there’s a difference between the BMJ and Nutrition and Food Science

A surprising mistake?

A surprising mistake?

HolfordWatch recently remarked on YorkTest’s chutzpah in selectively quoting from the recent Which? investigation. In the normal course of events and commenting, there has been some discussion of the lamentable Hardman and Hart audit of YorkTest customers. There has been a lot of confusion about whether the study was a clinical trial (no, it wasn’t) and even some confusion about where it was published: in some literature, YorkTest has been implying that it was published in the BMJ… Continue reading

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