Category Archives: Skepticism
I see this over and over again among otherwise very intelligent people; an odd belief that the latest “big” thing in exercise or weight loss will be a magic bullet that suddenly brings them the body they’ve always thought they should have. Zaggora hot pants (Burn more calories!), Skechers Shape Ups (reduce cellulite!), green coffee extract (100% natural!) – the list is basically endless. Leaving aside the notion that this will somehow make them happy (for I haven’t the knowledge or skills to even begin to tackle that), why do these bright people fall for it? I can’t answer that either. It’s potentially very harmful though – this tweet from @nchawkes says it rather well:
— Nick (@nchawkes) September 24, 2012
People end up spending frightening amounts of time, money and energy on these promises, and even when there’s temporary success (often due to diving into a new regime with a positive opinion, in my totally-un-evidence-based opinion) ultimately there’s stagnation at best, failure or regression at worst. These things are hugely destructive to body image and overall self-image.
So if I can’t explain the fascination with these things, the least I can do is provide a small extra weapon in the battle against profiteering and misinformation in the fitness world. (Aside: it’s worth noting that much of the misinformation is spread amongst well-meaning friends, just trying to help one another; this type is just as difficult to address as any other dearly-held belief).
My first pearl of wisdom is hardly novel: anything that seems too good to be true, is. The cold hard truth is that you can’t permanently change your body without permanently changing your diet and lifestyle; they needn’t be massive, life-altering changes, but they must happen. You also can’t permanently change your body by throwing money at it instead of good quality food and exercise (unless we’re talking surgery; that’s pretty permanent).
My second piece of advice is: apply critical thinking. Is there something you’re naturally skeptical about, or distrustful of? Apply that same level of suspicion to diet and lifestyle advice. New device guarantees weight loss in one workout? Great. What’s the mechanism? Does it seem plausible? Is it more likely that it’s just helping dehydrate slightly, thereby losing water via sweat? Never ever forget that water’s heavy; 1kg (2.2lb) per litre to be precise. Doubt everything.
Thirdly, and maybe most importantly (and predictably), demand evidence. Good quality evidence at that. Be ruthless. Be picky. Crucially, don’t accept anecdotes. These are everywhere in weight loss fads, to the point that I feel they’re worthy of a specially-adapted version of the anecdote rules:
- Did the person gain the advertised benefit, and maintain it?
- Was the advocated treatment the only one used?
- If it’s really so good, why aren’t doctors and fitness professionals everywhere advocating it?
I’m hoping to look at some individual claims in more detail, but hopefully this post will at least serve as a cue to get you thinking about the way you look at claims in the weight-loss industry.
Last time I discussed the problem of missing evidence of harm in homeopathy trials and consequently in systematic reviews. This time, I’m going to discuss some evidence of harm that we DO have. Sadly, it’s not comforting.
In December 2012, a systematic review of the adverse effects of homeopathy was published in the International Journal of Clinical Practice (aside: for a quick explanation of systematic reviews and adverse effects, take a look at volume 2 in this blog series). The authors of this review searched five databases of medical literature totalling nearly 50 million published trials (though likely with considerable overlap), and found just 38 articles that discussed case reports and case series of adverse events with homeopathy.
It’s worth noting at this point that if systematic reviews are the pinnacle of the evidence pyramid, case reports and case series are somewhere towards the middle or bottom, depending who you ask. They’re not ideal, because they’re not rigorous – they rely on someone not only noticing an adverse event and linking it to homeopathy, but taking the time to sit down and write about it and submit it to a journal. Then of course they’ve got to find a journal willing to publish it. If any of these steps don’t happen, there’s no published evidence for the rest of us to base our decisions on. So if our systematic review found 38 published reports, the obvious question is “how many were never recognised, written up, or published?” We’ll never know the answer to that. Sadly in the absence of high quality reports of harm from the published clinical trials, this is the highest level of evidence we have.
Back to the review. The 38 retrieved reports contained information relating to 1,159 people from all over the world. Surprisingly, only 17 of the reports related to indirect harms – the results of substituting conventional care with homeopathy – although some of those indirect harms were severe. Several people were admitted to hospital (including intensive care) due to replacing their conventional medicines with homeopathy, at least one was left with permanent effects, and one person died.
That leaves 1,142 people who suffered *direct* adverse effects as a result of using homeopathy. This seems rather counter-intuitive, and I’m at a loss to explain to explain many of them given that your average homeopathic remedy contains precisely no active ingredient. The authors of the review suggest that perhaps allergic reactions or ingestion of toxic metals (like arsenic or mercury) might be partly to blame. They also suggest that low dilutions of remedies might be a potential source of adverse effects, but point out that the vast majority of these reports were associated with remedies at 12C potency or below. To be clear, 12C is the dilution factor at which the chance of a remedy containing even one molecule of the original parent substance is effectively zero.
But whatever the mechanism, it seems clear that the review provides evidence of direct harm being caused by homeopathy. Some of these harms were reported simply as “mild”, with no other details offered. Some were potentially very distressing, like dermatitis, hair loss, and migraine. Some were very serious indeed, including anaphylaxis (life-threatening allergy), acute pancreatitis, cancers, and coma. Once again the consequences of the effects included hospitalisation, admission to intensive care units, and death. For a treatment modality generally touted as totally safe, that’s a pretty alarming set of side effects.
So what can we learn from it? There’s a valid argument to be made that there’s little point conducting more randomised controlled trials of homeopathy, because all of the good quality ones end up showing the same thing: no benefit over placebo. But where more trials are conducted, we should be demanding that all adverse effects are collected and reported in the same manner as trials of new medicines. Case series and reports are not proof of causation, but there is a bulk of evidence here that is concerning, and which should be addressed. The best way to do that is in good quality trials.
In the mean time, is there anything else we can do? Yes there is – in the UK at least. The medicines regulator in the UK, the MHRA, runs the Yellow Card Scheme. This is a mechanism by which anyone can report any side effect they experience after taking a medication. I would strongly urge anyone who has suffered an adverse event after using homeopathy (or who knows someone who has) to visit www.mhra.gov.uk/yellowcard. It’s quick and simple, and will help make remedies safer for everyone. Similar schemes will be coming into effect throughout the EU soon, but if you live elsewhere please check and see if there’s anything similar. We need all the data we can get!
The third post in mine and @SparkleWildfire’s blog series on the harms of homeopathy is now online! Here’s a little taster :
Indirect harms due to homeopathy can, as we’re trying to cover in these posts, come in various different guises. In my opinion, there is none more dangerous than this: poor advice from homeopathic practitioners.
To set yourself up as a homeopath in the UK, you don’t need any medical background. You also don’t need to register with any regulatory bodies or undergo any standardized training. Medical homeopaths, i.e. doctors who practice it on the side, are of course regulated by the GMC, but your common or garden variety homeopaths could basically be anyone.
To read the rest, head on over to A Healthy Dose of Skepticism.
We’re funny creatures, human beings – very easily swayed, and ruled by emotion a great deal more than some might believe. Most people like to think that they are quite rational, quite sensible; most people probably (secretly) think that they are more sensible than the average person. And yet we also believe some quite remarkable things.
Take homeopathy as an example; I have spoke to more than one very bright, intelligent person who has said words to the effect of “I know that homeopathic remedies don’t contain any active ingredient, and it’s probably a load of rubbish, but they definitely work for me”.
One of the most seductive forms of persuasion, for some reason, is anecdote. We see them all the time, often by another name – a testimonial, a case study, an interview – but it all means the same. Anecdotes seem to be a powerful way for people to communicate ideas – they make them relatable, and understandable. They also add a generous splash of emotion to the issue, and that’s not a particularly good thing
Because the fact is this: anecdote is not reliable. While we may think that we’re rational and swayed only by hard evidence, actually we human beings are all too easily tricked by all manner of things. Among the most common is confirmation bias, which is the name given to the very common scenario where we take action in the hope of producing some result and, if that result is obtained, assume that it was our action which caused it. There are lots and lots of very common examples – taking Echinacea for the common cold (or homeopathy for that matter), or arnica for a bruise. These things may or may not work, but the very fact that we expect them to have an effect means that when the inevitable happens and our cold clears up means that we will inevitably attribute that result to the remedy.
This is also a great example of the very similar concept of “regression to the mean”, which simply means that lots of things have a very predictable nature, and tend to get better on their own. Everyone knows that a cold will go away whether you treat it or not, but if you did happen to take that Echinacea tablet, isn’t it tempting to think that you helped yourself get better?
And that’s why anecdote is not reliable; these and many, many other biases and problems come into play, so that in most cases we have no idea if the “treatment” worked, or sometimes even if the person was sick in the first place. A fellow called Dr Moran, a retired surgeon from Australia, has a really rather lovely little website that gives us some tools to try and remain vigilant against this kind of thing. He has an article called How to Evaluate a Cancer Cure Testimonial, but really it just takes a few minor tweaks to make it into “How to evaluate a medical anecdote”.
So here are my golden rules:
- Was the person definitely ill, as shown by reliable tests, when the treatment was started?
- Did they get better, as judged by the same tests?
- Was the advocated treatment the only one used?
I haven’t really covered that 3rd point here, but it’s probably self-evident: if you did more than one thing to help yourself get better, how do you know which one worked?
And that’s it. It’s perhaps not particularly important if you’re just thinking about taking a herbal medicine for the common cold, but in other cases it might be. I’d urge anyone thinking about investing significant resources into a treatment (whether time, money, emotional input, or anything else) where the only evidence is an anecdote, testimonial, or similar to think through those three points. Be honest with yourself about the answers. You might just save yourself some cash, or some heartache.