Bad Science Case Study: Dog Bones

Bad Science Case Study: Dog Bones

The New Zealand Herald and Jimbo’s have provided us with an idealised “bad science” case study.

Today, the Herald published an article about a “trial” published by pet food manufacturer Jimbo’s: No bones about bones

The trial was intended to evaluate how eating bones affects the dental health of dogs. Thankfully the article makes it pretty clear why Jimbo’s would be looking into this, although it reads more like a quote from a press release than the declaration of a conflict of interest that it really is:

Jimbo’s sells over 300 tonnes of bones per year which help thousands of cats and dogs keep healthier teeth.

This trial seems rather special in that it’s a rare composite of just about every aspect of poor methodology all put together at once. I think it makes for an excellent “bad science” case study, which could hopefully be a good resource for journalists who might find themselves in danger of reproducing the Herald’s results.

And it’s not just journalists that can benefit from understanding this. Being aware of the potential shortcomings of research can make everyone more savvy when it comes to parsing science news. None this is particularly hard to understand at a high level.

Pared way down, designing a study is about two things:

  1. Finding a way to test a hypothesis by attempting to disprove it.
  2. Taking measures to account for as many sources of bias as possible.

Jimbo’s failed the first of those objectives spectacularly, but at least they were up front about it:

The Jimbo’s Dental Trial was carried out because we wanted to prove what we already knew – that a species-appropriate diet including a bone a day can improve or maintain dental health in our furry friends.

Jimbo’s Dental Trial – 2015

It’s roughly possible to pair up different aspects of good methodology to the source of bias they’re trying to account for. For example, having a large sample size is a way to diminish the effects of random variation within your sample population.

Here’s a list of the methodological problems with this Jimbo’s trial, and the corresponding sources of bias that they aren’t accounting for:

  • Source of bias
    Publication bias, where positive results are more likely to be published than negative results.

    How you should account for it
    Register your trial ahead of time, and ensure it gets published in a peer-reviewed scientific journal.

    What Jimbo’s did in their trial
    As far as I can find, the trial wasn’t pre-registered. Instead of being published in a peer-reviewed scientific journal, it was published as a PDF on the Jimbo’s website.

  • Source of bias
    Random variation within your sample population.

    How you should account for it
    Have as large sample size as possible. Of course larger sample sizes makes research more expensive, but if your sample is too small you won’t be able to reliably detect an effect.

    What Jimbo’s did in their trial
    The study used a sample of eight dogs. This was further reduced to seven after one dropped out for not following the diet.

  • Source of bias
    Regression to the mean, changes unrelated to the experiment, Hawthorne effect etc.

    How you should account for it
    Have an appropriate control group, for example a group of dogs not on the special diet.

    What Jimbo’s did in their trial
    The study did not include a control group.

  • Source of bias
    Bias, unconscious or otherwise, from researchers making measurements.

    How you should account for it
    Blind researchers making measurements so they don’t know whether the participant they’re evaluating was in the control group or the experimental group.

    What Jimbo’s did in their trial
    There was only an experimental group, so blinding was not possible.

    2016/10/30 Edit: Thomas Lumley has made a good point about blinding over on StatsChat. That is, the researcher evaluating the photos could have been blinded to whether each one was a “before” photo or an “after” photo. The study doesn’t mention if this was done, however.

  • Source of bias
    Differences between the populations in the control and experimental groups.

    How you should account for it
    Randomise which group each study participant ends up in.

    What Jimbo’s did in their trial
    There was only an experimental group, so randomisation was not possible.

The trial also lacked any sort of statistical analysis. Without a control group, there isn’t really a good way to do this, but it seems like Jimbo’s didn’t even try to figure out how likely it was that their result was a false positive.

I always find it amusing to see research that fails so spectacularly to be well-designed, as this has, but there’s a downside as well. This was picked up completely uncritically by the New Zealand Herald. In fact their story reads to me more like an advertisement or press release than the critical analysis I’d expect to see from a high quality media outlet.

Although in the end, the Herald did one thing right. They provided a link to the original research so all of its readers could see for themselves how spectacularly bad it is.

Colloidal Silver Blues

Colloidal Silver Blues

Don’t be fooled, colloidal silver sprays and creams won’t benefit your health.

In the continuing trend of the New Zealand media advertising ineffective health products as though it’s news, stuff.co.nz has published an article pushing colloidal silver for treating infections and skin conditions.


EDIT 2016/06/16: Last night I emailed the editorial team at stuff.co.nz with my concerns about this article. This morning they have responded to my complaint by withdrawing the article and replacing it with a correction. I think this is a commendable response. Here is part of the message I received in response this morning:

Your concerns were justified. The article clearly fell a long way below our editorial standards. We have moved to retract the article and replace it with an apology. You can read that at this link.

Geoff Collett, National Life & Style editor


The article quotes a naturopath and sales representative from Skybright Natural Health, a company that sells colloidal silver products, saying that:

Ionic colloidal silver is anti-bacterial, anti-fungal and anti-viral. It supports the immune system when the body is under attack and micro-organisms cannot build up resistance to it.

It’s also completely safe for every single person in the family to use, babies included.

Skybright1

What the article doesn’t tell you is that there’s no evidence colloidal silver can do any of that. And we’ve known this for quite some time. In 1999, the FDA issued a rule on colloidal silver stating that:

all over-the-counter (OTC) drug products containing colloidal silver ingredients or silver salts for internal or external use are not generally recognized as safe and effective and are misbranded.

Over-the-Counter Drug Products Containing Colloidal Silver Ingredients or Silver Salts | Final rule by the FDA

And despite that rule being 17 years old now, the state of the evidence remains unchanged. America’s National Center for Complementary and Integrative Health (NCCAM) has a rather succinct “bottom line” on colloidal silver products, last assessed as up to date in September 2014:

How much do we know about colloidal silver?

There are no high quality studies on the health effects of taking colloidal silver, but we do have good evidence of its dangers.

What do we know about the effectiveness of colloidal silver?

Claims made about the health benefits of taking colloidal silver aren’t backed up by studies.

What do we know about the safety of colloidal silver?

The U.S. Food and Drug Administration (FDA) has said that colloidal silver isn’t safe or effective for treating any disease or condition.

Colloidal Silver | NCCAM

Colloidal silver has been on my radar for quite some time now. Here in New Zealand, it’s been promoted for various conditions: predominantly infections and skin conditions, but also extending as far as cancer. The evidence for its efficacy is equally absent for all of these claims.

I’m aware of three New Zealand companies that have been challenged on their colloidal silver health claims via complaints to the Advertising Standards Authority: Colloidal Health Solutions, Salud New Zealand, and Liquid Pearl. None of these advertisers were able to provide evidence to support the health claims they were making. (For full disclosure, I gave advice to the complainants for two of those complaints.)

In 2013, I got in touch with another company promoting colloidal silver products in New Zealand, “Health House”. I wanted to know what evidence they had to back up the claims they were making. In particular, I wanted to know if they had any evidence that came from the product being tested in vivo, i.e. in a living organism.

Much of the evidence used to back up health claims about colloidal silver products comes from in vitro testing, as opposed to being tested in people or animals. This is dangerous; many many potential new drugs may appear effective in in vitro tests but then turn out to be ineffective or worse, unsafe, when tested in animals or people. So if we rely on this low quality evidence to make health decisions, we run the risk of using ineffective and/or harmful products.

Unsurprisingly, the response I received from Health House was that that they don’t have any credible evidence to back up their claims. As well as telling me this, they also decided to send me a list of (anonymised) customer testimonials.

In my opinion, this is a very deceitful tactic. Relying on incredibly low level evidence to back up health claims, and promoting them alongside testimonials which can be both misleading and very convincing, is not an ethical way to promote a healthcare product or empower patients to make informed decisions. That said, it is also a very common tactic among promoters of colloidal silver and other ineffective health products.

Using health testimonials in advertising is prohibited in the Medicines Act for this very reason, although that provision is hardly observed and barely enforced.


As well as saying colloidal silver can treat various conditions, promoters like Skybright also claim it is safe. In the quote for the stuff.co.nz article, Skybright even said it was safe for use on babies. As far as I’m aware, that’s essentially true, but with one big caveat. The reason it’s true is that it’s only legal to sell colloidal silver in New Zealand if it’s at too low a concentration to have any effect.

In 2003, then Minster of Health Annette King answered a question about colloidal silver from Rodney Hide (quoted in part):

Rodney Hide: is Medsafe permitting colloidal silver manufacturers and promoters in New Zealand to distribute material containing therapeutic claims; if so, why; if not, what has it done to stop such distribution?

Annette King: No. Distributing material containing therapeutic claims for colloidal silver products would breach the Medicines Act 1981… Colloidal silver products containing less than 10 parts per million of silver do not need consent to distribute under the Medicines Act providing no therapeutic claims are made. Therefore, once references to therapeutic claims have been removed and as long as the product contains less than 10 ppm of silver, there is nothing to prevent these products being advertised again.

5463 (2003). Rodney Hide to the Minister of Health | New Zealand Parliament

Even if colloidal silver was able to treat infections, at a concentration as low as 10 ppm it would be surprising if it had any effect. Luckily, those effects you’ll be missing out on include your skin turning permanently blue.

I’m not joking. It’s called argyria. Your skin turns blue and stays that way, and it can be caused by taking too much colloidal silver. It looks like this:

Argyria | Paul Karason

That’s a photo of Paul Karason, probably the most famous sufferer of argyria caused by colloidal silver. More cases of harm caused by colloidal silver can be found documented on the website whatstheharm.net. One sufferer of argyria caused by colloidal silver, Rosemary Jacobs, has written about the dangers of colloidal silver and the ignorance of some naturopaths promoting it.

While legally sold colloidal silver products aren’t likely to be harmful, there is a real potential for harm if you’re going to make your own colloidal silver. DIY “make it yourself” colloidal silver kits aren’t hard to find for sale online, including on sites like Trade Me. I honestly do worry that someone is going to read that it’s safe for babies, and wind up using some colloidal silver someone made at home which is far more concentrated than 10 ppm.


On a lighter note, it just so happens that my favourite bit of New Zealand pseudoscience comes from an ad for Skybright’s colloidal silver cream, so of course I just have to share it here. When you see as much quackery as I do, it helps to be able to laugh at it on occasion.

In the listing for Skybright colloidal silver cream on the NetPharmacy website (it’s a real Auckland pharmacy, not just online), the promotional text explains:

when cells become infected with a bacteria they lose a positive electron and become negatively charged

Skybright Colloidal Silver Cream | NetPharmacy

1EDIT NOTE 2016/09/27: The naturopath who was cited in the Stuff article has contacted me to say that they had left Skybright before the Stuff article was published, and that the quote has been incorrectly attributed to them. As such, I have changed the attribution to Skybright.

It’s Detox Season

It’s Detox Season

Summer is detox season, but beware misleading health advice.

Every summer, we are bombarded with advertisements, editorials, and advertorials chastising us for all the toxins we have poisoned ourself with by indulging in fruit mince pies and Christmas ham. But it’s okay, we are told, for there is a solution to this toxic overload. And that solution is…

The detox

Sound advice and playing to our holiday guilt gets a foot in the door. Eat your greens, shed those Christmas kilos, make a New Year’s resolution to avoid toxins. They may even appeal to the rationalist in us: your kidneys and liver are your detox organs, but they need support to do their job optimally.

Next comes the sale. They just so happen to know the perfect thing you can do to detox. Their dietary supplement, their green juice, their herbal tea. This is the secret to ridding your body of toxins, we are told.

But these products, so often forgotten by March, rarely stand up to closer inspection. No evidence (although perhaps some testimonials) are offered in support, specific toxins are rarely mentioned, and claims about what the products can do are often restricted to vague claims such as “support your body’s natural detoxification process”. Such ambiguity is necessary to avoid being held accountable for specific claims.

In practice, the current regulations allow for claims like “supports your body’s natural detoxification process” to be made without supporting evidence. If a product is said to “support” something that happens already in a healthy person, and there’s no evidence it has harmful side effects, the regulators will tend to steer clear of it.

This hasn’t stopped action being taken against detox claims. In the past two years, there have been 12 complaints against detox ads laid with the Advertising Standards Authority. In every single case, the advertisement was found to be misleading.

So who can we trust? In the case of advertisements and advertorials it’s clear that the company behind them has something to gain from us buying their products. Conflicts of interest are important, and in those contexts they are clear. But can we trust other sources of information to be accurate and free from this bias?


If conflicts of interest are hidden from us, we can be misled. A well-informed society depends heavily on the press, and it’s in our best interest for mainstream media to report without having undeclared conflicts of interest. One of the Press Council’s principles describes why conflicts of interest are an important consideration for the press:

To fulfil their proper watchdog role, publications must be independent and free of obligations to their news sources. They should avoid any situations that might compromise such independence.

The New Zealand Herald recently published a column giving health advice about detoxing from an expert, but didn’t adequately declare the author’s conflict of interest. In truth, the columnist makes a living from the sale of the exact products they were promoting in the article, but you wouldn’t know unless you did some digging.

The column was published on Sunday November 29, just before the start of detox season. It was headlined “Detoxing: What you need to know” and clearly marked as the opinion of Sandra Clare:

Sandra Clare detox opinion headline

Sandra is described briefly before and after the article:

Sandra is a medical herbalist, medical anthropologist, and columnist for the NZ Herald.

Sandra Clare is the founder of Artemis (artemis.co.nz) offering New Zealanders a premium range of traditional plant medicine products. She is one of New Zealand’s most highly qualified health professionals in her field, as a Swiss trained medical herbalist and a medical anthropologist (M.A.). Sandra is currently completing a PhD in health science at the University of Canterbury in collaboration with the Chair for Natural Medicine of the University of Zürich, Switzerland.

She’s clearly framed as an expert in the field she’s writing about, rather than someone with a conflict of interest. So it certainly wouldn’t surprise me if someone reading her article about everything they “need to know” about detoxing would take her advice seriously. But let’s take a closer look at the advice she gives.

The article starts off giving some sound advice, appealing to the sceptic in us that knows “quick fix” health products are often too good to be true:

At this time of year, detox diets and miracle products spring up like brightly coloured daisies. Many of them promise quick weight loss and eternal youth at the drop of a hat, or a pill.

It is easy to get swayed by enticing marketing when trying to find an approach to rejuvenate or drop those annoying extra kilos.

However, most of these products and fad diets are neither successful nor sustainable, and their harsh, artificial composition can strip the body of essential nutrients resulting in a worse state of health.

So far, I’d been nodding along to her article. She’s got her foot in the door, and it’s not too long before she moves on to the sale. According to Ms Clare, the secret to detoxing is drinking two types of herbal tea, and making this a lifestyle change instead of something you do for just a brief duration:

In more serious health issues it is advisable to follow a targeted cleansing regime for a minimum of eight weeks, as this is the minimum time it takes for the liver to restore and cleanse deeper layers. By the end of that time most people find it easy to incorporate better choices into their daily lives for long-term health.

The easiest way to support your body’s daily detoxification is to take a medicinal tea with bitter liver herbs before breakfast. Liquid plant medicine is perfect for detoxification since water has additional flushing benefits over and above the therapeutic ingredients of the tea.

Follow this with a kidney cleansing medicinal tea mid-morning to complete the flush by removing the released water-soluble toxins. Golden rod, horsetail, birch leaves, nettle and raspberry are traditionally used to improve kidney function and help clear the body of water-soluble metabolic wastes and toxins, excess sodium, uric acid and inflammatory by-products. I call this combination your daily ‘internal shower’.

At first glance this just looks like advice from an expert in the field, not a marketing pitch for specific products. But not all is as it seems.

As mentioned in Ms Clare’s bio, she is the founder of Artemis Natural Healthcare. And it just so happens that Artemis sells a “Liver Detox Tea” and a “Kidney Cleanse Tea”. The wording in her article seems like it could easily have been tailored specifically to match the marketing for these teas, listing their ingredients and using terms such as “kidney cleansing medicinal tea” and “medicinal tea with bitter liver herbs”.

Surprise surprise, if you search for either of those phrases from the article on Google in a New Zealand context, the first results are for Artemis’ products:

Google Liver Detox Tea

Google Kidney Cleanse Tea


I found about these products when the December catalogue for Health 2000, which is New Zealand’s natural health retailer and has been in trouble in the past for misleading claims about toxins, was released on the Wednesday after the Herald article. It advertises Artemis’ “Liver Detox Tea”, which prompted me to check further and led to me finding out about their “Kidney Cleanse Tea” through their website.

Health 2000 Artemis Liver Detox Tea

I sent a message to the New Zealand Herald’s online editors the day after I found this out, to express my concern about this conflict of interest and about the misleading content of the article. It’s been over a week now, and disappointingly I’ve had no response from them. You can read my message at the bottom of this article.

The morning after I sent that message, the New Zealand Herald was distributed along with a copy of the Health 2000 December catalogue. The same catalogue advertising one of the products Ms Clare was surreptitiously promoting in her Herald column only days earlier.

As far as I’m aware the New Zealand Herald has yet to acknowledge the full extent of this conflict of interest, but I hope that hearing about this will make you think twice before trusting detox advice. Without taking the time to look behind the curtain, it can be hard to tell if someone stands to gain financially from the advice they’re giving.

As always, if you think a health claim might not be all it claims to be, the best approach is to ask for evidence. If all you’re given is anecdotes, it’s probably not trustworthy. In the case of detox advice, asking for specifics on which toxins they’re talking about can also be a good approach.


It seems appropriate for me to state here that I have no conflicts of interest to declare. All I’ll gain if you take my advice to be sceptical of misleading detox claims is peace of mind.


Here is the letter I sent to the New Zealand Herald’s online editors:

Earlier this week I read an opinion piece published on your website by Sandra Clare, entitled “Detoxing: What you need to know” (http://www.nzherald.co.nz/lifestyle/news/article.cfm?c_id=6&objectid=11552384)

I’m concerned that the article contains misleading content and that her substantial conflict of interest is not made adequately clear to readers.

As noted at the bottom of the article, the author is the founder of Artemis, a for-profit business that sells herbal healthcare products. One of the products this company sells, advertised in the latest Health 2000 catalogue which was released this week, is “Liver Detox Tea”. You can see it advertised on page 22 of the catalogue online here: http://www.health2000.co.nz/december-2015_1268

In Ms Clare’s article, she says:

“The easiest way to support your body’s daily detoxification is to take a medicinal tea with bitter liver herbs before breakfast. Liquid plant medicine is perfect for detoxification since water has additional flushing benefits over and above the therapeutic ingredients of the tea.”

This very closely echoes the marketing for her business’ “Liver Detox Tea” product.

Artemis also sells a “Kidney Cleanse Tea” to “Flush those toxins away”. According to the Artemis website it contains Birch leaves, Golden Rod, Horsetail, Nettle, and Raspberry leaf. In her article, Ms Clare also says:

“Follow this with a kidney cleansing medicinal tea mid-morning to complete the flush by removing the released water-soluble toxins. Golden rod, horsetail, birch leaves, nettle and raspberry are traditionally used to improve kidney function and help clear the body of water-soluble metabolic wastes and toxins, excess sodium, uric acid and inflammatory by-products. I call this combination your daily ‘internal shower’.”

This too very closely echoes the marketing for her business’ “Kidney Cleanse Tea” product.

It seems fairly unlikely that the timing of her article and the increased marketing of “detox” tea products by her business are a coincidence. It is absolutely in the interest of your readers to be made aware of her conflict of interest involving these products, and it does not seem to me like this has been done adequately.

Furthermore, I’m concerned that much of the information presented in her column is likely to be misleading. It is absolutely true, as she says in the opening paragraphs, that “detoxification” is the role of your kidneys and liver. However, the article is written in such a way as to imply, without any supporting evidence as far as I am aware, that products like the “Liver Detox Tea” and “Kidney Cleanse Tea” sold by her company are able to provide health benefits such as “improved immune system” and “better circulatory and lymphatic function”.

I’m also concerned that the article advises readers to “Reduce pharmaceutical drug intake”. As the conflict of interest statement refers to Ms Clare as “one of New Zealand’s most highly qualified health professionals in her field”, I am concerned that this advice might be taken seriously by some readers and as reliable health advice, and result in some degree of harm.

I think we are all aware that summer is the time of year where businesses in the “natural health” industry most strongly market “detox” products. As the chair of the Society for Science Based Healthcare, I see a significant amount of misleading advertising for these products, particularly at this time of year.

Over the past two years, 12 advertisements about detox products have been complained about to the Advertising Standards Authority, and in every one of those cases the advertisement was found to be misleading. Many more of these advertisements will surely have been similarly misleading, but will not have attracted formal complaints.

I understand that opinion pieces such as this may not be bound by the same requirements for accuracy and balance as non-editorial content, but I hope that you nevertheless do care about and understand the importance of the accuracy of content presented as expert health advice.

I hope you will discuss these matters with Ms Clare, and ensure that her conflict of interest is stated much more clearly if you publish future articles from her.

Here’s the follow-up message I sent the next morning:

Further to my message last night regarding your columnist Sandra Clare’s conflict of interest, this morning I see that the New Zealand Herald was distributed with the December Health 2000 catalogue.

This is the catalogue that I raised as a concern due to the fact that it advertises Ms Clare’s “Liver Detox Tea” product.

The fact that the New Zealand Herald is distributing marketing for one of the products lauded in a Herald article makes it all the more important that the nature of this conflict of interest is made clear to readers.

I hope you will treat this matter seriously.

Press Council Complaint: Homeopathy in the Wairarapa Times-Age

In February this year, an article was published in the Wairarapa Times-Age (both in print and online) headlined Use of natural remedies is on the rise. The article discussed some specific cases of so-called “natural remedies” being used to treat serious diseases, such as intravenous vitamin C for leukaemia and homeopathy to treat various forms of cancer.

Except for a brief mention at the bottom of the article encouraging people with cancer to talk to their doctor before using any “alternative therapies”, there was no mention of the fact that none of the treatments discussed are supported by any reliable evidence. Instead, the article uncritically included various quotes such as this, from homeopath Claire Bleakley:

Featherston-based homeopath Claire Bleakley said she has treated cancer patients using similar natural remedies [to intravenous vitamin C] – significantly extending life expectancy.

She mentioned two of her patients in particular: A man with tumours who lived for seven years after being given two to live, and a woman with ovarian cancer who lived 15 years past her initial prognosis.

“There have been some exceptional results,” Mrs Bleakley said.

“We are indoctrinated to think chemotherapy is the only cure for cancer, but alternative [remedies] have been proven to be more life giving.”

Medical anecdotes such as these unfortunately tend to be very convincing despite the fact that they can also be completely misleading. The reasons why people might get better are varied and complex. Without running a controlled test, there’s no way to know whether or not a particular treatment contributed to an improvement in health. That’s exactly why we need to undertake rigorous clinical trials before we can say with confidence what the effects of any particular treatment are. It’s also why the Medicines Act prohibits the use of health testimonials like this in advertisements, although that restriction of course doesn’t extend to news articles in publications like the Times-Age.

I thought, and still do think, that the lack of balance in this article has the capacity to do serious harm. I wrote to the editor of the Wairarapa Times-Age to make my case, and to give some suggestions for how they might attempt to mitigate the damage this article could do, in a formal complaint:

To whom it may concern,

I am writing to you to make a formal complaint regarding the article “Use of natural remedies is on the rise” published in the Wairarapa Times-Age this morning:
http://www.nzherald.co.nz/wairarapa-times-age/news/article.cfm?c_id=1503414&objectid=11399310

This article uncritically promotes the use of so-called “natural remedies” such as vitamin C or homeopathy for the treatment of cancer. They are promoted by the inclusion of quotes such as “There have been some exceptional results”, regarding the treatment of cancer with homeopathic products.

None of the relevant controversy regarding these treatments is discussed in the article. Although there is a brief note at the end that “those living with cancer [are encouraged] to consult their doctor or specialist before embarking on any alternative therapies”, this does not sufficiently address the important and relevant fact that these treatments are entirely unsupported by scientific evidence, as well as the utter implausibility of treatments like homeopathy.

The failure to discuss the lack of scientific evidence supporting these treatments, as well as the complete lack of plausibility underlying homeopathy, violates the Press Council’s principle of “Fairness, Accuracy and Balance”. The description of this principle on the Press Council’s website states that:

“Publications should be bound at all times by accuracy, fairness and balance, and should not deliberately mislead or misinform readers by commission or omission. In articles of controversy or disagreement, a fair voice must be given to the opposition view.

Exceptions may apply for long-running issues where every side of an issue or argument cannot reasonably be repeated on every occasion and in reportage of proceedings where balance is to be judged on a number of stories, rather than a single report.”

This is not a long-running issue in which readers can readily be expected to be familiar with the lack of evidence supporting the treatments discussed in the article, so the exception should not apply. There is significant controversy surrounding the issues discussed in this article, but a fair voice has not been given to the opposition view.

Particularly as this article could lead to people living with serious diseases such as cancer to rely on ineffective treatments such as homeopathy, its lack of balance has the potential to cause real and serious harm. Therefore it is important that the Wairarapa Times-Age take appropriate action to prevent this harm by amending the article, publishing a prominent correction, or publishing a followup article linked to from today’s article, that discusses the lack of evidence and plausibility underlying the treatments discussed in today’s article.

If the Wairarapa Times-Age has trouble finding any experts to talk to about this topic, either the Society for Science Based Healthcare (http://sbh.org.nz/contact) or the Science Media Centre (http://www.sciencemediacentre.co.nz/contact-us/) will be able to help.

Sincerely,

Mark Hanna
Society for Science Based Healthcare

Despite sending a follow-up email a few days later, I still hadn’t heard back from the editor over the next 10 working days, which is the deadline set in the Press Council’s complaints process as the time to wait before escalating a complaint to them if you don’t hear back from the editor. After I forwarded my complaint to the Press Council, the editor contacted me to apologise that he’d overlooked my complaint messages, which was apparently due to his having to deal with another complaint about the same article from Peter Griffin, manager of the Science Media Centre (Peter is also the editor and manager of Sciblogs, where my blog is syndicated, and we’d discussed our complaints via email prior to submitting them).

When I forwarded my complaint to the Press Council, I fleshed it out a bit more. I won’t quote the whole thing here as a lot of it would just be repeating myself, although I’d be happy to share my full complaint if anyone would like to see it, but here is one part I added that I think is important and worth sharing:

As far as I’ve been able to tell, the Wairarapa Times-Age has not published a large number of articles regarding this, so it cannot be argued that the counterpoints have already been published in earlier articles.

When it comes to whether or not readers can be expected to be familiar with the important facts not mentioned in this article, I would like to bring the Press Council’s attention to a 2009 study (I am not aware of any more recent data collected on this) published in the New Zealand Medical Journal entitled “Beliefs about homeopathy among patients presenting at GP surgeries”. This study can be accessed for free on Page 94 of this PDF:
http://www.nzma.org.nz/__data/assets/pdf_file/0010/17794/Vol-122-No-1295-22-May-2009.pdf

This study found that only 8 out of 124 respondents disagreed to some extent that “There is good scientific evidence that homeopathy works”, and only 24 respondents reported that they believed homeopathic products were either “very dilute” or that there was “nothing there”. In contrast, 82 respondents agreed to some extent that “There is good scientific evidence that homeopathy works”, and 80 believed that homeopathic products are either “Very concentrated”, “Moderately concentrated”, or “Moderately dilute”.

Contrary to these common beliefs, most homeopathic products are diluted to the point that it is astronomically unlikely that there is even a single molecule of the original ingredient present in the product, and there effectiveness is thoroughly unsupported by scientific evidence. For example, a rigorous review undertaken by the Australian Government’s National Health and Medical Research Council (NHMRC) in 2013 investigated the evidence regarding homeopathy for 68 clinical conditions and concluded that “The available evidence is not compelling and fails to demonstrate that homeopathy is an effective treatment for any of the reported clinical conditions in humans”
(https://www.nhmrc.gov.au/_files_nhmrc/file/your_health/complementary_medicines/nhmrc_homeopathy_overview_report_october_2013_140407.pdf)

For this reason, and especially because the article discussed the use of ineffective therapies in the treatment of terminal illness, it is very important that stories such as this be balanced. As I stated in my original complaint to the editor, I believe the article in its current form has the capacity to do serious harm and that the Wairarapa Times-Age has a responsibility to mitigate this harm. An appropriate response would be amending the article, publishing a prominent correction, or publishing a followup article linked to from the article from the 10th of February that discusses the lack of evidence and plausibility underlying the treatments discussed in today’s article.

(The NHMRC link I provide there is from their 2013 conclusion. Within 2 weeks of submitting this complaint, however, they released their final statement on homeopathy, which states “there are no health conditions for which there is reliable evidence that homeopathy is effective”. This statement was not reported in the Wairarapa Times-Age)

Once the complaint was escalated to the Press Council, the editor of the Times-Age was given an opportunity to respond, then I had a final opportunity to write a short response to that. His primary argument was that the topic of “alternative medicine” was a long-running issue in a wider context, and that the exemption to the principle of balance should apply because other media have reported on the opposing side of the issue.

I strongly disagree with this argument. Although it’s true that media like the Wairarapa Times-Age do not exist in a vacuum, I don’t think this should mean that they don’t have a responsibility to provide balanced articles for their readers. The way I interpret the Press Council code, the exception can be useful when an article is part of a series of articles on the same issue, and when taken in the context of other articles in the series the overall view still maintains an appropriate balance. In the interest of balanced reporting, I believe exceptions to the principle of balance should be applied very sparingly.

Unfortunately, the Press Council disagreed with me. They have ruled not to uphold the complaint, and you can view their entire decision on their website here:
Case Number: 2426 MARK HANNA AGAINST WAIRARAPA TIMES-AGE

Here’s a link to their similar ruling regarding the complaint from the Science Media Centre:
Case Number: 2425 SCIENCE MEDIA CENTRE AGAINST WAIRARAPA TIMES-AGE

Here is a summary of their decision:

The Press Council agrees with the editor that the debate over alternative remedies is sufficiently well known not to require balancing comment in every story about them. The subject falls within the exception to the principle of balance for issues of enduring public discussion.

The complainant in this case raised the important question of whether the exception can be invoked for an article in a newspaper that may not itself have covered both sides of the debate. The Council considered this point closely and came to the view that the exception has not been applied as narowly as the complainant contends and should not be. A newspaper, even if it is the sole newspaper of its locality, does not exist in a vacuum. Its readers, meeting an uncritical story on the supposed popularity of homeopathy and natural remedies, are likely to be aware the efficacy of these treatments is strongly contested by medical science.

I think this is a very worrying precedent to set. Newspapers such as the Wairarapa Times-Age can now feel justified in publishing unbalanced articles on topics such as homeopathy without feeling bound to uphold the Press Council’s principle of balance. The public have a reasonable expectation, given that the Press Council exists to uphold standards in reporting and its first principle is that articles should be accurate, fair, and balanced. While it’s a good idea to take everything you read with a grain of salt, you should be able to feel justified in expecting media reports on controversial topics to provide a balanced view. I worry that people might read articles such as this with that assumption in mind, and falsely conclude that the views omitted from the article are not merited.

I’m also rather frustrated that the Press Council concluded that anyone reading articles such as this is “likely to be aware the efficacy of these treatments is strongly contested by medical science” even though I provided data from a survey that found only 6% of respondents disagreed that “there is good scientific evidence that homeopathy works”. I understand that the survey I cited was conducted 6 years ago, but as I said in my complaint I’m unaware of anything more recent.

Although I don’t think it is, I really hope that the Press Council’s conclusion that most people are aware that homeopathy is not supported by evidence is correct. Following last year’s story about Green MP Steffan Browning backing homeopathy for ebola and March’s story about the Australian National Health and Medical Research Council concluding that homeopathy does not improve people’s health, I think there is some basis to believe that more people are familiar with the lack of evidence surrounding homeopathy than 6 years ago, but I don’t expect there would be that large a difference.

One positive thing to take away from this, at least, is that the journalist who wrote the article said in a Facebook comment that she understood the article was unbalanced and that she should have done better. I hope she’ll take this as a learning experience and, when she or other Wairarapa Times-Age reporters write on matters of “natural health” in the future, that they get in touch with the Science Media Centre to provide that much-needed balance. If we can’t rely on the Press Council to hold journalists to a high standard of balanced reporting, then we’ll have to rely on journalists’ and editors’ own standards.

EDIT 2015/04/14 10:05 am: Peter Griffin, who also complained to the Press Council about this article, has published his thoughts on the ruling as well: When balance goes out the window

EDIT 2015/04/04 1:13 pm: The Wairarapa Times-Age has published a short article on this ruling: Times-Age supported by Press Council

EDIT 2015/04/14 2:21 pm: Grant Jacobs has also published a post with his thoughts on this ruling: Press Council rules on knowing readers minds?

EDIT 2015/04/15 2:51 pm: Andrew Bonallack, the editor of the Wairarapa Times-Age, has published his thoughts on the Press Council decision in an opinion piece for the Times-Age: Your right to choose sacrosanct

Irradiation of Food and Compulsory Labelling

Queensland Fruit Fly | Photo by James Niland
Queensland Fruit Fly | Photo by James Niland

Biosecurity is a big issue for New Zealand. Being a group of islands fairly isolated from all other landmasses and having quite a unique native ecosystem (many native birds with no native mammalian predators and few native land mammals), we have a lot to lose from introduced species. There are also biological threats to industry that we have to try really hard to keep out of the country, such as Queensland fruit fly. There’s good reason why the Ministry for Primary Industries (MPI, formerly MAF) reacted so strongly when one of these flies was found in Whangarei in April 2014. If enough of these flies made it into New Zealand to self perpetuate, they could cause massive damage to New Zealand’s $5 billion horticulture industry.

In order to kill off any biosecurity risks, including disease-causing organisms and foodborne pests, various treatments (also known as “phytosanitary actions” when used on plant products) can be used when importing products into New Zealand. Different products that can be imported each have an Import Health Standard (IHS) that documents the process of importing them.

For fruit and vegetables being imported, they need to come with a phytosanitary certificate from their country of origin, to say that either they have been inspected by someone from MPI and they couldn’t find any pests, they come from a certified pest free area, or they have been treated to kill any pests. A sample of the products is also inspected by MPI when arriving in New Zealand, and if any pests are found then the products will have to be treated if they are to enter New Zealand.

The treatment used depends on a few things, such as what pest was found that they’re trying to kill. For example, assuming I’m interpreting the IHS correctly, if Thrips palmi is found in a shipment of capsicum from Australia it would be fumigated with methyl bromide at 32 g/m3 for 2 hours. Whereas if Conogethes punctiferalis were found, then the capsicum would be irradiated with a minimum dose of 250 Gy (Grays; 1 Gray is equivalent to 1 Joule of energy absorbed per kg of food).

EDIT 2015/02/01:

The previous paragraph is incorrect. Those treatments are the ones that should appear on the phytosanitary certificate, having been performed in the country of origin. The treatments done if a pest is found when they arrive in New Zealand are determined in the Approved Biosecurity Treatments Standard. So for fresh fruit and vegetables (page 37), if insects except for fruit flies (not slugs and spiders) are found then they have to be fumigated with methyl bromide at a particular rate and temperature for a particular duration (presumably depending on the pest and the produce). Looking at this standard, it seems human food doesn’t get irradiated if pests are found when it arrives in New Zealand. According to MPI’s list of treatment providers (direct PDF download), there is only one facility in New Zealand able to provide food irradiation, which is in Wellington.


Methyl bromide is an insecticide, and it’s also recognised as an ozone-depleting substance. Because of this, its use is tightly controlled. It’s only allowed to be used for a few specific purposes, one of which is quarantine, and New Zealand has to provide statistical data to the Ozone Secretariat on the annual amount of methyl bromide that we use. It’s nasty stuff – even skin contact with high enough concentration of the gas can cause severe blistering – but after being used to fumigate food it apparently dissipates fairly rapidly. There are some objects that MPI won’t fumigate with methyl bromide for various reasons, which are described in their info sheet I linked to above.

Irradiation is quite different. Using either Cobalt 60, x-rays, or an electron beam food is blasted with a specific amount of ionising radiation. Cobalt 60 is a radioactive source of this radiation, but as it emits gamma rays instead of neutrons it doesn’t make anything else around it radioactive. Both x-rays and electron beams are created by non-radioactive sources and can be switched on and off.

When food is irradiated, the process kills any organisms that are living in the food, including disease-causing organisms and pests. The food does not become radioactive, instead it will just be slightly warmed from the energy it absorbs. Also, the radiation will trigger some chemical changes, but these occur only in amounts comparable to heat treatments. In this way it’s quite similar to the process of pasteurisation used to make milk safe to drink.

In 2010, following an extensive literature search, the European Food Safety Authority (EFSA) published their Scientific Opinion on the Chemical Safety of Irradiation of Food. They found that the new evidence published since their previous decision in 2003 wasn’t enough to change their opinion that “there is not an immediate cause for concern” regarding the safety of irradiated food.

Irradiated Food symbol | FSANZ
Irradiated Food symbol | FSANZ

The strongest negative evidence they found seemed to be a case in which cats ate a diet consisting largely or entirely of highly irradiated (25.7 to 53.6 kGy, i.e. 100 to 200 times as much as in the capsicum example from earlier) cat food and subsequently suffered from leukoencephalomyelopathy (LEM). This evidence doesn’t necessarily have any relevance to humans though; in another report dogs ate the same pet food and didn’t exhibit LEM. Also, as the incident was only linked to one specific lot of one specific brand of pet food it’s unclear if irradiation was the culprit at all.

Even though irradiated food appears to be entirely safe to eat and not significantly different from food that hasn’t been irradiated, it is currently compulsory to label irradiated food in New Zealand under the Australia New Zealand Food Standards Code Standard 1.5.3.

MPI’s Food Smart website has an informative page on food irradiation. It’s quite clear on several important points (you can read their full answers on the page):

Does irradiation change food?

At the approved doses, changes to the nutritional value of the food caused by irradiation are insignificant and do not pose any public health and safety concerns.

Some treated foods may taste slightly different, just as pasteurized milk tastes slightly different from unpasteurized milk. There are no other significant changes to these foods.

Does irradiation make food radioactive?

No.

Is it safe to eat irradiated food?

Yes. Irradiation of food does not make the food unsafe to eat.

The World Health Organisation, the Food and Drug Administration in the US and the American Medical Association all agree that irradiated food products are safe to eat.

The FDA’s page on food irradition has an informative “Debunking Irradiation Myths” inset:

Irradiation does not make foods radioactive, compromise nutritional quality, or noticeably change the taste, texture, or appearance of food. In fact, any changes made by irradiation are so minimal that it is not easy to tell if a food has been irradiated.

FDA

It also states that:

FDA has evaluated the safety of irradiated food for more than thirty years and has found the process to be safe. The World Health Organization (WHO), the Centers for Disease Control and Prevention (CDC) and the U.S. Department of Agriculture (USDA) have also endorsed the safety of irradiated food.

FDA


Earlier this week, the Herald published an article by Sue Kedgley on irradiated food. In my opinion that article is a load of unscientific scaremongering. Here are a few excerpts that appear clearly intended to be more emotive than informative:

But irradiated food is anything but fresh. It’s been exposed to radiation doses that are between three and 15 million times the strength of x-rays. The Brisbane radiation facility uses Cobalt 60 to irradiate food, a radioactive material that is manufactured in Canadian nuclear reactors, and shipped to Australia in special unbreakable steel canisters.

I visited the Brisbane irradiation facility in 2004. Boxes of food travel by conveyor belt into an irradiation “chamber”. The irradiation process breaks down the molecular structure of food; destroys vitamins in food, and creates free radicals and other “radiolytic compounds” that have never been found in nature, and whose effect on human health is not known.

Also of concern is the fact that in 2008 the Australian Government was forced to ban irradiated cat food after more than 80 cats died or became seriously ill after eating irradiated cat food.

This begs the question – if cats can die, or become ill from eating irradiated cat food, what could be the cumulative effect on humans of eating significant quantities of irradiated food? There’s no benefit to New Zealand consumers, and only risks to our growers, from imported irradiated produce.

Her comment that irradiation “breaks down the molecular structure of food [and] destroys vitamins in food” is quite at odds with the evidence that the nutritional content of irradiated foods are not changed significantly. This statement is entirely blown out of proportion, it’s like describing a papercut as having “ripped my flesh apart”.

She also doesn’t mention any of the details regarding the cat food incident, such as that their diet consisted largely or wholly of food irradiated 100-200 times as much as human food generally is, that the same food seemed to have no negative effects when eaten by dogs, or that the incident was only linked to one specific lot of one brand of cat food. How it relates to humans consuming irradiated food, if it has any implications on that at all, is not clear but her reaction is just scaremongering.

Her article appears to have been prompted by a couple of changes to the regulations that are being considered:

FSANZ is currently assessing Application A1092 seeking permission to irradiate twelve specific fruits and vegetables. A call for submissions on our assessment is expected to be released in the second half of 2014.

Food Standards Australia New Zealand | Food irradiation

FSANZ plans to start work on recommendation 34 (that the requirement for mandatory labelling of irradiated food be reviewed) later this year.

Food Standards Australia New Zealand | Labelling review

Here’s a link to Application A1092. That page specifies the 12 fruits and vegetables involved as apple, apricot, cherry, nectarine, peach, plum, honeydew, rockmelon, strawberry, table grape, zucchini, and scallopini (squash).

Ms Kedgley describes these potential changes as:

the Government is about to approve the importation of irradiated apples, peaches, apricots and nine other fruit and vegetables from fruit fly-infested Queensland.

If they succeed, retailers will be able to sneak irradiated produce into the food chain, and it will be sold, unlabelled, as if it was “fresh”.

Surely consumers have a right to know whether the apples they are buying are fresh, or have been imported from Queensland and exposed to high doses of radiation to sterilise them and kill off potential fruit fly lava?

Red apple
Red apple | Photo by Abhijit Tembhekar

Looking at the IHS for fresh fruit and vegetables (direct PDF download), you can see that honeydew, rockmelon, strawberry, grape, zucchini, and scallopini are already included, they just aren’t yet allowed to be treated via irradiation. As far as I can tell the others – apple, apricot, cherry, nectarine, peach, and plum – can’t currently be imported from Australia.

Given that the entire function of irradiating food is to kill unwanted organisms such as Queensland fruit fly larva, I think it seems disingenuous of Ms Kedgley to repeatedly refer to it as though allowing these products in will bring Queensland fruit fly to New Zealand. The reason why we can’t currently import these products is because of that fly, but allowing them to be treated by irradiation would let us safely import them.

On the issue of labelling, this seems to be a very similar issue to compulsory labelling of genetically modified foods and foods containing genetically modified ingredients (this is currently mostly compulsory in New Zealand). In that case, as with food irradiation, opposition generally seems to be driven by idealogical issues with the technology used or misinformed beliefs that it’s somehow unsafe, even though it’s entirely safe. It’s effectively a lose/lose situation – if labelling isn’t mandatory then “What are they trying to hide?” but if it is mandatory then “They wouldn’t have to put it on the label if it wasn’t bad for you”.

If you want to oppose the addition of those 6 new fruits to the list of foods that can be imported from Australia on the basis of supporting New Zealand farmers then okay, that’s a different argument altogether that has nothing to do with irradiation. There doesn’t seem to be much reason to oppose this on grounds that irradiated food may be unsafe to eat though.

Foods are not allowed to be irradiated unless they have been through a pre-market safety assessment process conducted by FSANZ

http://www.foodsmart.govt.nz/elibrary/food_irradiation_.htm

Given that irradiated food doesn’t appear to be unsafe, is there really any reason to keep labelling of irradiated food compulsory? If anything, isn’t compulsory labelling most likely to make people think that means it’s bad or unsafe when it isn’t? If it’s all about allowing consumers to make informed decisions, that would be rather counterproductive.


I’m lucky enough to know someone who’s a food scientist. Claire Suen has an MSc in Food Science from the University of Auckland, and I contacted her to ask for her thoughts on the process of food irradiation. Here are some of the things she had to say in response to some of the common arguments opposing food irradiation:

[Irradiation] changes the nature of food: carcinogenic, loss of nutrients etc.

So does cooking, burning toast, deep frying, etc. Irradiation causes minute changes to the food and some loss of nutrients such as vitamins, but these have all been thoroughly researched and the results are readily available. In short, no significant changes to the food have been found.

Regarding the lost of nutrients, I usually point out to people that this is negligible considering the nature of the food.

FSANZ have published some comprehensive risk assessment reports in the past, and using the latest report on tomato as an example:

Nevertheless, even assuming an upper estimate of vitamin A and C loss of 15% following irradiation from all fresh tomatoes, capsicums and tropical fruits (with existing irradiation permissions), estimated mean dietary intakes of these vitamins would decrease by 2% or less and remain above Estimated Average Requirements following irradiation at doses up to 1 kGy, with dietary intake typically derived from a wide range of foods.

The impact of cooking and storage time on nutrients in food is far more severe than the effects of irradiation.

Here’s a link to that FSANZ report on Irradiation of Tomatoes & Capsicums (direct DOC download)

There are better alternatives

Irradiated food saves cost for the manufacturers/importers/supermarkets because it eliminates otherwise costly alternatives.

Methyl bromide for example, is not 100% effective against insect eggs and larva, particularly if they are buried inside the fruit or seed. Storage pest such as beetles and weevils are extremely difficult to control and often need a combination of methods such as heat treatment, and fumigation. For herbs and spices, irradiation can be used to control pathogens such as salmonella and E. coli. No other method is as effective. But because consumers in NZ are against it, we have to use methods such as steam sterilisation and heat treatment, which impacts on the flavour and quality of the product. Consumers sometimes do not understand the amount of work MPI and the importers have to do to make sure foreign organisms do not get in the country. All it will take is a slack importer, a missed check, or an incomplete fumigation. What of the products that have to be destroyed due to microorganism contamination, or spoilage? If they had been irradiated, this wastage wouldn’t happen.

We don’t need irradiation since we can just buy local products

Unfortunately NZ is a small country and we have limited produce. I’m not saying we can’t get by without EVER importing anything, but, it seems to me that these people don’t realise just what the consequences are. Sure, we don’t have to import apples, or nectarines, but what about the tropical fruits not grown locally? Or spices? Let’s not eat fresh mango again, or curries, since pepper used to be worth its weight in gold because it’s not grown in Europe. We can’t get away from importing and by not using irradiation, NZ business have to use more costly, and less effective alternatives, which means all these cost are passed ultimately onto the consumers. I understand people’s concern that this will hurt local producers, but that is a question of economy and has nothing to do with the safety of irradiated food.

Now coming to the question of labelling

Unfortunately, it’s a no-win situation. If we label then consumers will think something is wrong with it, if we don’t label it’s as if we are hiding something. There is simply no way to beat that logic. In my opinion, if we don’t label products which have been heat treated, or fumigated, then we shouldn’t need to label for irradiation. But because consumer backlash is so strong, I wouldn’t want to give haters a chance to play the “Ah ha you are hiding something” or “give me my freedom of choice” card.

I say let’s put irradiated fruits on the shelves and label it as such so I can chose to buy it because it will be cheaper and better!

I think that last point says it all really. As a food scientist, Claire is quite familiar with the topic of food irradiation, and she would choose to preferentially buy irradiated food because she understands the process to be safe, effective, and not detrimental to the food.

Poor Science Reporting on the Paleo Diet

This morning I saw an article in the NZ Herald on the “paleo diet” that rather frustrated me. It seems like a great example of poor science reporting, trying its hardest to turn a study into a story instead of doing any actual science reporting. The role of a science reporter is not to sensationalise, it’s to accurately report on science, and that includes making the drawbacks of a study clear and not exaggerating the conclusions.

In this case though, it looks like the author chose to omit half the results of the study, presumably so as not to pollute the narrative they had chosen. The take-home message of the article can be found in the first paragraph:

the best way to lose weight is by copying our ancient ancestors, a study suggests.

I’m not even going to get into the problems with characterising the so-called “paleo diet” as “copying our ancient ancestors”, that’s been adequately covered elsewhere. The information used to support this weight loss conclusion is that the study in question found that:

Women who adopted the so-called Palaeolithic diet lost twice as much weight within six months as those who followed a modern programme based on official health guidelines.

Wow, that sounds impressive. Case closed, right? Except, if you look at the actual study (not open access, unfortunately), which of course is not linked to from the online article, you’ll find another result that is curiously omitted from the Herald article:

Both groups significantly decreased total fat mass at 6 months (−6.5 and−2.6 kg) and 24 months (−4.6 and−2.9 kg), with a more pronounced fat loss in the PD [Paleolithic-type diet] group at 6 months (P<0.001) but not at 24 months (P=0.095).

So there was a statistically significant difference in fat loss after 6 months, as mentioned in the article, but after 24 months there was no statistically significant difference in fat loss between the groups. That is a negative result.

Although there was still an observed difference in fat loss between the groups at 24 months, it wasn’t big enough for the researchers to be reasonably confident that it wasn’t just due to random variation. That’s partly due to the size of the difference observed, and also because the study was so small. 70 people split into 2 groups is very small for this kind of study, whereas a good sample size would be hundreds or even thousands of participants, not just a few dozen. Of course, such large studies are much more difficult and expensive to undertake, so a lot of smaller studies like this do happen. Sample size is very important though – small studies like this are not nearly as reliable as the much larger ones – so it’s important to remember to take the sample size into account when evaluating a study’s conclusions.

The Herald article does mention, way down near the bottom, that all of the participants in the study were obese postmenopausal women. Everywhere else, however, it avoids that caveat and seems to imply that the conclusions should be applicable to everyone, or at least to all women.

It’s also rather frustrating that the article says that the study “found [the “caveman diet”] more effective than some modern diets”, and that this study suggests it is “the best way to lose weight”, even though the study didn’t compare it with “some modern diets”. It compared it with a single other diet, one based on the Nordic Nutritional Recommendations.

If the Herald wants some tips on how to report on science, a great place to start would be to take another look at the science itself. The conclusion in the abstract of the study they’re writing about seems much more appropriate, even if it does seem a bit dismissive of the negative 24 month results:

A PD [Paleolithic-type diet] has greater beneficial effects vs an NNR [Nordic Nutritional Recommendations] diet regarding fat mass, abdominal obesity and triglyceride levels in obese postmenopausal women; effects not sustained for anthropometric measurements at 24 months. Adherence to protein intake was poor in the PD group. The long-term consequences of these changes remain to be studied.

Then again, perhaps I should be glad the Herald didn’t reprint the original headline from the Daily Telegraph:

Caveman diet twice as effective as modern diets

I’m not sure I could come up with a more misleading headline if I tried.

Despite the horrific headline, the original article does have a bit more information in its second half from the study’s primary author that was truncated from the Herald’s reprint.

Iridology and Credulity

The NZ Herald’s Life & Style section has (once again) affirmed their dedication to credulity, in an article by Donna McIntyre extolling the supposed virtues of iridology in what reads like an advertisement for a naturopath called Peter Riddering, ND (Not a Doctor) – Iridology: What the eyes reveal

EDIT: It seems the article has been moved into the NZ Herald’s Health & Wellbeing section (a subset of Life & Style): Iridology: What the eyes reveal

The article’s contents consist mostly of quoting Mr Riddering talking about how iridology supposedly works. No attempt is made, of course, to provide evidence supporting the claims he’s making. In fact, it seems the closest thing to supporting evidence that is offered is an argument from antiquity:

Modern iridology dates back to a Hungarian doctor Ignatz Peczely in the late 1800s but Peter says the Mayans, Egyptians, Chinese and Incas were also aware of iris markings and their link to health.

I’d like to flesh out the history of iridology a bit more than was done in the Herald article. The story goes that a young Ignatz Peczely observed a dark fleck in the iris of an owl with a broken leg (some reports claim that he broke its leg himself). After the owl had recovered, he noticed that the owl’s iris no longer contained the dark fleck, but instead contained a few white lines in about the same place.

When he had grown up, Peczely apparently became a homeopath (a sure sign of a quack if ever there was one). In his misguided attempts to treat people, he apparently noticed a similar fleck to the one he once observed in the owl in a man who, apparently, also had a fracture. After this, Peczely started to create a “map”, based on his observations, detailing how he thought the iris acted as a map of the entire body.

This “homunculus approach” to diagnosis, where one particular body part is believed to act as a map of the rest of the body, is relatively common in fake medicine. For example, tongue diagnosis is central to the practice of traditional Chinese medicine (TCM). Reflexology, which is essentially the idea that pretty much anything can be cured by a foot or hand massage, is another example.

Now let me just stop here. Nothing I have said so far really matters when it comes to whether or not iridology is a valid method of diagnosis. The things I have described are red flags, but they are far from conclusive. The real problem is what happened after Peczely’s original observations. Here’s what should have happened:

After making his initial observations, Peczely should have developed a hypothesis that internal medical problems can be diagnosed by examining the iris. In order to determine whether or not his hypothesis was true, he should have set up and carried out a set of rigorous tests that were capable of disproving his hypothesis.

That is not what happened.

As far as I can tell, iridology is based off “maps” that have been created not via rigorous testing of falsifiable hypotheses, but as a result of singular observations coupled with confirmation bias. Iridology is simply not supported by anatomy or physiology, and has never been shown to be an effective method of diagnosis or recognised as a legitimate diagnostic approach. Despite this, Peter Riddering charges people $65/hour for iridology sessions.

As he mentions in the Herald article (perhaps the only useful piece of information in there):

naturopaths are not allowed to make medical diagnoses. If [Mr Riddering] does come across anything, he suggests client go to their doctor

The way I see it, if you’re worried you might be ill here are 2 of your options:

  1. You see Peter Riddering, not a doctor, who uses a bogus method of diagnosis and, if he finds anything, tells you to see a real doctor.
  2. You see a real doctor.

I have to admit, I really don’t see the appeal in the first option. It seems the only differences are that the first option…

  • costs more
  • essentially funds fake medicine
  • carries a greater risk of misdiagnosis
  • takes more time

I’m not a medical doctor, so I’m going to give you the only health advice I’m qualified to give: ask a medical doctor

Here are some evaluations of iridology I found via a very quick search on Google Scholar, along with relevant excerpts from their abstracts:

  • An Evaluation of Iridology by Allie Simon; David M. Worthen, MD; Lt John A. Mitas, II, MC

    Iridology had no clinical or statistically significant ability to detect the presence of kidney disease. Iridology was neither selective nor specific, and the likelihood of correct detection was statistically no better than chance.

  • Iridology: Not Useful and Potentially Harmful by E. Ernst, MD, PhD, FRCP (Edin)

    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.

  • Iridology: A critical reveiw by Lennart Berggren

    [Controlled] clinical trials and experiments conclusively show that iridology has no ability to detect disorders in other parts of the body; there are sufficient proofs that iridology is purely conjectural. Iridology is of no medical value and might even be a potential danger to people seeking medical care. It should be exposed as a medical fraud.

  • Changing belief in iridology after an empirical study by P. Knipschild

    My paper on iridology presented evidence against its validity as a diagnostic aid.

    Note that this article itself did not assess the validity of iridology, but instead how doctors’ beliefs change when confronted with evidence against it.

  • Iridology: A Systematic Review by Ernst E

    Conclusion: The validity of iridology as a diagnostic tool is not supported by scientific evaluations. Patients and therapists should be discouraged from using this method.

  • An investigation of the relationship between anatomical features in the iris and systemic disease, with reference to iridology by PhD T.J. Buchanan, PhD C.J. Sutherland, PhD R.J. Strettle, PhD T.J. Terrell, MSc A. Pewsey

    The results demonstrate that the diagnosis of these diseases [ulcerative colitis, asthma, coronary heart disease or psoriasis] cannot be aided by an iridological style analysis.

  • Can Iridology Detect Susceptibility to Cancer? A Prospective Case-Controlled Study by Karsten Münstedt, Samer El-Safadi, Friedel Brück, Marek Zygmunt, Andreas Hackethal, and Hans-Rudolf Tinneberg

    Conclusion: Iridology was of no value in diagnosing the cancers investigated in this study.

If you’re at all worried that I’ve cherry picked the studies that support my conclusions, the quoted articles were simply all the links on the first page of results when searching for “iridology” on Google Scholar.

It seems iridology simply does not work. Anyone who says otherwise is either ignorant or dishonest.