Are Claims in Advertisements in Medical Journals Supported by RCTs?

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The Netherlands Journal of MedicineThere is at present a considerable amount of legislation being implemented concerning the role of claims linked to food and supplements.

Considerable complications in the food industry are being faced as the European Food Safety Agency apply very tight filters to allow different levels of claims to be applied to products. One complaint is that the pharmaceutical approach to validation is unsuitable and therefore unworkable as foods are not the same as medicines in terms of mechanisms and actions.

Though it is of course accepted that food is vital to managing health and lmiting disease risk there is a central dogma that protecting the consumer is paramount, even if the blind conviction in this aim results in the exclusion of safe and health contributing food and supplements.

It might be considered that the pharmaceutical approach must therefore be water tight or at least a very robust approach and accordingly that advertisments for medicine would be reliable and based on high quality research relevant to the medicine being advertised. In particular they use an extensive amount of data extracted from randomised clinical trials (RCT’s) regarded by many as the only applicable standard of evidence gathering. An earlier post looked at a JAMA that through significant doubt on the validity of many medical research trials that actually make it to publication.

Now, a recent study, supporting previous investigations of a similar nature, confirms that ‘claims’ made in advertisements in high quality medical journals such as the Journal of the American Medical Association, the Lancet, the New England Journal of Medicine, etc might not always be supported by high-quality evidence, and referenced studies may have been sponsored by the pharmaceutical industry itself. [1]

By and large they found, only 17% of referenced RCTs investigated between 2003 – 2005 attached to all adverts in high quality medical journals are of good quality, supportive, and not sponsored by the company itself.

This investigation supports the Lancet study from 7 years ago in which a similar analysis found a considerable discrepancy between medical claims made and the supportive studies.

The 1993 Lancet article concluded:

Doctors should be cautious in assessment of advertisements that claim a drug has greater efficacy, safety, or convenience, even though these claims are accompanied by bibliographical references to randomised clinical trials published in reputable medical journals and seem to be evidence-based.

The free access journal PLOS in 2009 undertook a systematic review of 24 journal articles looking at the quality of medical advertising they discovered overall that only 67% of the claims in adverts were supported by a systematic review, a meta-analysis or a randomised control trial and concluded:

Evidence from this review indicates that low quality of journal advertising is a global issue. As information provided in journal advertising has the potential to change doctors’ prescribing behaviour, ongoing efforts to increase education about drug promotion are crucial. The results from our review suggest the need for a global pro-active and effective regulatory system to ensure that information provided in medical journal advertising is supporting the quality use of medicines. [2]


What does this mean to us as nutritional therapists, well medicine and nutrition are disciplines in which the purported benefits linked to supplement of medicine consumption need to be explained to the consumer as well as the practitioner both disciplines have a responsibility to be accurate and fair.

The budgets available to pharmaceutical products are vast compared to those available to bodies exploring the potential benefits for food/supplements. The very financial difference should allow the medical adverts to apply a more rigorous level of qualification, espescially as they are normally associated with a level of risk. Foods and supplements need to be carefully described and as legislation evolves this will be enforced by law as well as moral and financial decisions.

It is of use to us to remember that for all the criticism that is leveled at the alternative medicine community for lack of credible (RCT) research, it appears that the very organistaions that hve promoted the RCT strategy as qualifying research are unable to be relied upon to use them appropriately anyway.


[1] Heimans L, van Hylckama Vlieg A, Dekker FW.Are claims of advertisements in medical journals supported by RCTs? Neth J Med. 2010 Jan;68(1):46-9. View Abstract View Full Paper

[2] Othman N, Vitry A, Roughead EE (2009) Quality of Pharmaceutical Advertisements in Medical Journals: A Systematic Review. PLoS ONE 4(7): e6350. doi:10.1371/journal.pone.0006350 View Full Paper

[3] Villanueva P, Peiró S, Librero J, Pereiró I. Accuracy of pharmaceutical advertisements in medical journals. Lancet. 2003 Jan 4;361(9351):27-32. View Abstract

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