Some of my local readers will have seen last night Lorelei Mason of TVNZ (Television New Zealand) present an horrific case of an iridiologist treating a skin cancer on the scalp which went on to invade the patient’s skull, eventually requiring major surgery.

(Source: wikipedia.)

(Source: wikipedia.)

You can read a text account of this news presentation, with comments from readers, or view the TV presentation on-line. (If you are viewing the video, you will need to wait for the advertisement to complete. Those squeamish about viewing exposed brains, may wish to avoid the appropriate parts of the video.)

Dr. Swee Tan, interviewed in the presentation, says that natural health practitioners ought to be registered. Some commenters offer that registration will not solve the problem.

My own thoughts, as a non-medical person-on-the-street, are that in one sense registration might legitimise the more moderate use of ’remedies’ like iridology, which grates given that many, if not most, of these remedies are nonsense under any use, but on the other hand registration offers some control over the worst extremes of misuse by obligating practitioners to adhere to guidelines.

Despite my unease at giving practices that lack evidential support credibility, my initial thoughts are that Swee Tan’s suggestion makes some sense: clients approaching someone offering medical remedies–of any kind–should have some assurance that the practitioner is being held to at least some basic responsibilities and at least some basic level of education in medicine. Ideally I would like to see unsound ‘natural remedy’ practices gone, but realistically this is unlikely to happen any time soon. Registration might be a good compromise in the meantime. Personally, I would like to see these guidelines also include some level of control over use of remedies that are not backed by evidence.

Quackwatch regards iridology as nonsense. (This site also contains the confessions of a former iridologist.)

For those wanting a more formal approach, a short, readable medical review of the evidence for iridology is available free on-line (Archives of Ophthalmology: Ernst 118(1)120-121, 2000). None of the controlled, investigator-masked studies found supported iridology. The final two paragraphs are worth quoting:

Might iridology be doing any harm? Waste of money and time are two obvious undesired effects. The possibility of false-positive diagnoses, ie, diagnosing–and subsequently treating–conditions that did not exist in the first place, seems more serious. The real problem, however, might be false-negative diagnoses: someone may feel unwell, go to an iridologist, and be given a clean bill of health. Subsequently, this person could be found to have a serious disease. In such cases, valuable time for early treatment (and indeed lives) can be lost through the use of iridology. No data are available on how frequently such problems occur. Thus no firm judgments are possible as to the damage done by iridology in real life.

In conclusion, few controlled studies with masked evaluation of diagnostic validity have been published. None have found any benefit from iridology. As iridology has the potential for causing personal and economic harm, patients and therapists should be discouraged from using it.

[My emphasis added.]

Perhaps we might add to the author’s list of harms: when an iridologist continues to treat a serious illness rather than referring their client to a medical practice?

The case Mason presents is a clear illustration of a source of harm in using natural remedies that has been raised in the context of other remedies on Sciblogs (2 links): delaying medical help. In some circumstances this delay will allow an illness to progress to a stage that it requires major treatment that could have been avoided, or delay it too long so that it cannot be effectively treated.


I am not a medical practitioner. The views expressed here are only opinions.

Other articles on Code for Life:

137 years of Popular Science back issues, free

The inheritance of face recognition (should you blame your parents if you can’t recognise faces?)

Homeopathy check-up: Not in the health system, disclaimers on labels

Tracking disease and human migration through genetics

Positive encouragement for vaccination