Another Holford Response

April 2, 2008 at 10:36 am (Alternative Medicine, Bad Science, Patrick Holford, Supplements) (, , , , , , , , , )

Yesterday I covered Patrick’s response to criticism of his comments on the Gladys Block paper. Now, I’ll take a brief look at the reasons for Mr Holford’s continued support for York Test and York Test’s IgG blood testing kits.

Two types of antibodies, called IgE and IgG, are thought to be the main contenders for most allergic reactions. Both can be reliably tested using a technique known as ELISA.

Here’s my first problem with this response: IgE and IgG are said to be the  ‘main contenders’ for allergic reactions. The expert view seems to be that the “significance of IgG anti-food antibodies is particularly uncertain since the sera of many children with such antibodies in their serum tolerate the foods in question perfectly well.” (The American Academy of Allergy, Asthma and Immunology, via breathspakids). The breathspakids blog is also the source for this quote from The Australasian Society of Clinical Immunology and Allergy:

IgG antibodies to food are commonly detectable in healthy adult patients and children, independent of the presence of absence of food-related symptoms. There is no credible evidence that measuring IgG antibodies is useful for diagnosing food allergy or intolerance, nor that IgG antibodies cause symptoms. The exception is that gliadin IgG antibodies are sometimes useful in monitoring adherence to a gluten-free diet patients with histologically confirmed coeliac disease. Otherwise, inappropriate use of food allergy testing (or misinterpretation of results) in patients with inhalant allergy, for example, may lead to inappropriate and unnecessary dietary restrictions, with particular nutritional implications in children.

Given that there is no credible evidence that measuring IgG antibodies is useful for diagnosing food allergy or intolerance, I can’t see how it can possibly be relevant that IgG “can be reliably tested using a technique known as ELISA.”

Patrick also provides a reference to back up his claims for effectiveness. This reference is to a survey on whether people felt better after following a diet which eliminated the foods that had been identified as allergens by Yorktest. I had a look on Pubmed to see whether I could find G Hardman, Journal of Nutrition and Food Science (2007), vol 37, pp 16-23. Nothing. Which is a shame really – I had quite fancied reading that. Apparently, the study found consistent evidence that noticeable benefit was gained from removing offending foods from the diet. We just don’t know what kind of evidence – were the respondents simply reporting on how they felt or were there objective measures of benefit? Holford then points out that: the more strictly they followed their allergy-free diet, the better their results. That’s an interesting point. Until recently, I had never heard of the confounding effect of compliance. There is a fascinating piece in the New York Times that deals with the Bias of Compliance.

If you want to learn more about expert opinion on IgG, or the House of Lords or Advertising Standards Authority views on this kind of testing, Holford Watch have a piece here that includes direct quotations from a House of Lords committee and from an ASA adjudication. The breathspakids blog has an entire category on IgG. The Bad Science post about the show is here and you can listen again here. I love Radio 4.

10 Comments

  1. dvnutrix said,

    *cough* Hardman & Hart (pdf) paper. There is a good reason that you don’t find the journal in PubMed…

    Taubes’ epidemiology article is truly fascinating and the ‘bias of compliance’ is an element that is frequently lacking from discussions of the placebo effect, regression to the mean etc.

  2. jdc325 said,

    “Taubes’ epidemiology article is truly fascinating and the ‘bias of compliance’ is an element that is frequently lacking from discussions of the placebo effect, regression to the mean etc.”
    Absolutely – it’s not something I’d ever come across until I read about it in the NYT via a link from an article on Holford Watch.

    Thank you for the link.

  3. pv said,

    Can you imagine reading anything like the NYT epidemiological article in the magazine of any UK newspaper?

  4. Profnick said,

    In fact the journal is called “Nutrition & Food Science”. (There is another journal called “The Journal of Nutrition and Food Science”). “Nutrition & Food Science” is cited in CAB Abstracts but the following extract from the instructions to Authors indicates that it is not a peer reviewed journal:

    “The reviewing process

    Emerald has appointed an Editor who is a respected expert in the subject area concerned. The decision whether or not to publish is made by the Editor. Second opinions may be taken. ”

    The editor is Dr Mabel Blades,a “freelance dietitian and nutritionist” as well as popular author, (including books with Anthony Worall-Thompson). (http://www.qmnds.demon.co.uk/html/about_us.html)
    Remind you of anyone?? I’ll leave the rest to your imagination.

  5. jdc325 said,

    That’s interesting Profnick, I’ve just double-checked the reference given by Mr Holford and it certainly says Journal of Nutrition and Food Science. I’d better drop them an email – I’m sure they’ll want to correct their response.

  6. draust said,

    You mean… Patrick has published something inaccurate and potentially misleading on his website…?

    I am shocked, jdc. Deeply shocked.

    Incidentally, setting up “para-Journals” that sounds a bit like real journals but aren’t is a long-standing tactic of the AltMed world. The grand-daddy of this trend is Abram Hoffer and his journal (and Patrick’s fave publication output) the Journal of Orthomolecular Medicine. At least the JOM’s current title tells you upfront that it is from the barking fringe – when it started up in the late 60s Hoffer called it the Journal of Schizophrenia.

    Many of the Alt Journals, even those published by the big academic publishers, are pure Cargo Cult Science. So what the standards are in an un-referee-d magazine …

  7. jdc325 said,

    Well, I emailed Stephanie Fox to point out the error on Patrick’s website and I have yet to receive an acknowledgement. Just in case you are wondering, the mistake is yet to be corrected. I wondered if perhaps the mistake had slipped their minds, so I’ve just sent a reminder to info@patrickholford.com and Stephanie Fox by email.

    EDIT [around 2.30pm]: Have now received an email from Ms Fox. It seems that there was a very straightforward reason why the reference had not yet been amended and I’m sure that the correction will be made soon enough.
    EDIT 2 [17.45]: The non-peer reviewed journal is now correctly referred to as ‘Nutrition and Food Science’.

  8. jdc325 said,

    Incredibly, YorkTest have made a similar error in their brochure. Covered here by HolfordWatch.

  9. YorkTest, Hardman & Hart: there’s a difference between the BMJ and Nutrition and Food Science « Holford Watch: Patrick Holford, nutritionism and bad science said,

    […] 25 August: jdc reminds us that Patrick Holford has also been confused about where the Hardman and Hart paper was published. Possibly related posts: (automatically generated)Which?, YorkTest and Cambridge Nutritional […]

  10. The Paper That Never Was « jdc325’s Weblog said,

    […] also made an unfortunate error in the citation of a paper on allergy testing. I wrote about it here, and a commenter noted that the journal is called “Nutrition & Food Science”, not “The […]

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