May 26 2011

CBC Program on Homeopathy

Recently CBC in Canada aired a program on homeopathy for their series on consumer protection called Marketplace. The segment was titled Cure or Con and was generally a good program. It was not a hard-hitting skeptical treatment of homeopathy, but it was a fair treatment of the evidence and arguments concerning homeopathy. There was no “false balance”, although they did give homeopathy proponents an opportunity to tell their side of the story.

Generally the program was considered a “win” among skeptics – a rare bit of good journalism on a controversial and complex topic.

Of course, the homeopathic community was not pleased (a reliable sign that the show did a good job). Just read the comments beneath the program linked above and you will see a long list of displeased homeopathy advocates running through the list of logical fallacies and making many misstatements of fact. The homeopathy community, in fact, organized a negative feedback campaign in response to the segment.

Such feedback tests the journalistic integrity of reporters and outlets that have taken an unpopular position on a topic, or one that displeases a vocal minority. I am glad to see that CBC has not caved to this feedback, and in fact they have responded with a statement that supports high standards in science journalism.

The Complaint

The official complaint was made by Kathyrn Robbins, prompting an ombudsman review. She dismissed the report as biased (an easy charge to make – bias is often in the eye of the beholder) and made a number of specific, and very typical, pro-homeopathy points. She wrote:

“How homeopathy works is indeed a mystery — but when did mystery become a logical basis for concluding that something does not work or is, even worse, a con?”

This is the standard defense of not only homeopathy but any magical treatment. There are two main errors in this statement. The first is that it is a straw man – the basis for the conclusion that homeopathy does not work is largely from direct clinical evidence that homeopathy does not work, regardless of its plausibility or putative mechanism. Homeopathic preparations are indistinguishable from placebo – the standard interpretation of which is that they do not work. Defenders of homeopathy accuse critics of ignoring positive studies, but it is they who are cherry picking. Systematic reviews of all the clinical evidence overwhelmingly show that homeopathy is a placebo.

Second – there is a profound difference between not knowing how a treatment works and our most basic and fundamental science telling us that it cannot possibly work. This is not just about a “mystery” or lack of knowledge – we can reasonably assess the plausibility of a scientific claim based upon the scientific knowledge that we have so far accumulated. We can do this while simultaneously acknowledging the limits of our current knowledge, and the wild card of the unknown.

With respect to homeopathy, most preparations do not even have a single molecule of active ingredient remaining after their extreme dilution. So how can they possibly have a physiological effect on the body? Homeopaths resort to the most implausible, essentially magical, explanations – that the remedies contain the “spirit” of the substance that was diluted in them, or that water retains the “memory” of the substance (which can somehow survive being placed on a sugar pill, evaporating, being absorbed in the body, and traveling through the blood).

This is not just a “mystery” – for homeopathy to work major chunks of our understanding of reality would have to be wrong. This is scientific implausibility in the extreme. A reasonable approach to take to such claims is that the evidence that they are true has to be at least equal to the evidence that tells us they cannot be true. There would need to be a mountain of high quality evidence for homeopathy to be taken seriously, but instead we have evidence that is essentially negative. The only reasonable conclusion to draw from massive implausibility and negative evidence is that homeopathy does not work.

How do homeopathy apologists answer this charge (when not ignoring it)? The ombudsman’s report indicates:

While she agreed that the bulk of evidence in support of homeopathy was anecdotal, she said that the more than 200 years of such successes “cannot be discounted. . .people will not continue to pay for treatments that do not work.”

This is not a justifiable premise, given what we know of human psychology, mechanisms of self-deception, and a few thousand years of cultural history. Anecdotal evidence can be discounted (by solid scientific evidence). Millions, even billions, of people can be deceived by confirmation bias, statistical naivete, placebo effects, and other mechanisms of self deception. We also have numerous historical examples of popular treatments we now know to be worthless or harmful.

In fact the entire history of human knowledge (factual knowledge about how nature works) is one of cultural beliefs (largely superstition or philosophy-based or simply quirky cultural history) being systematically replaced by science-based ideas. When we started to take a rigorous systematic look at nature with methods that control for bias we found that almost everything we believed about the world was wrong.

Proponents of homeopathy want to go backwards – they want to eschew scientific knowledge for the messy and biased methods that created uncounted superstitions and primitive beliefs – i.e. anecdotes. Why – because anecdotes give them the answer they want, and science doesn’t. But also our brains are programmed to respond to anecdotes, to be compelled by personal stories. We emotionally have a hard time discounted the personal experience of others, and especially ourselves. It takes critical thinking skills and knowledge of the mechanisms of bias and deception to overcome this emotional gut response – but that is what science requires.

Robbins goes on to say:

“Here are the facts: You cannot scientifically prove that homeopathy does or does not work.”

Ah – the last refuge of the pseudoscientist. Your science cannot test my woo. How has she established the “fact” that homeopathy is somehow immune to scientific investigation? If there is a real effect from homeopathy, as proponents claim, then we should be able to document that effect statistically. Putative mechanism is irrelevant – such an effect can be measured. This is simply a lame special-pleading excuse for the scientific evidence not supporting one’s view.

Further – homeopathy apologists often try to maintain, simultaneously, that the science does support homeopathy (by cherry picking the positive data), and then when it’s pointed out that the evidence is actually negative, they switch to “science can’t test homeopathy.”

CBC Response

The CBC gives a cogent defense of their journalistic methods and adequately defends their conclusions. In fact, they justify a much harsher treatment of homeopathy than the one they gave. In an attempt to seem fair, they softened their blow considerably. The soft approach did not prevent the backlash from true-believers, however.

I much prefer the no-nonsense approach taken by the British Commons committee that the CBC report cites for justification, writing:

The most recent significant study of homeopathy came from a 2009 British Commons committee following months of testimony. The committee considered the ultra-dilution notion “scientifically implausible” and that systematic reviews and analyses “conclusively demonstrate that homeopathic products perform no better than placebos.”

Among its conclusions: “We regret that advocates of homeopathy, including their own submissions to our inquiry, choose to rely on, and promulgate, selective approaches to the treatment of the evidence base as this risks confusing or misleading the public, the media and policy-makers.”

In fact the report called homeopathy “witchcraft” – an accurate description.

Regarding the issue of balance, the CBC reports writes:

The achievement of balance does not mean mathematical equivalence; rather, the important principle is that different views are, in the words of the CBC policy, “reflected respectfully.”

This is reasonable. It avoids the trap of false balance. It also explains the soft approach taken. But I do think a journalist must also consider what the real story is, and not just reflect everyone’s views. The real story hear is that homeopathy is witchcraft. It can’t work, and the evidence shows it doesn’t work. An interesting angle to this story is why people believe in it anyway – what flaws of psychology and neurology are at work. And also how it is marketed and aggressively promoted.

Conclusion

Homeopathy is a con – a massive 200 year old con. That’s the real story. Journalists should not be afraid to tell that story, and they should (to borrow an old cliche) wear the criticism of true believers as a badge of journalistic honor.

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