A recent comment to a blog-post about alternative treatments for cancer inspired me to ponder a bit. I think it is noteworthy because it exemplifies so many of the comments I hear in the realm of alternative medicine on an almost daily basis. Here is the comment in question:

“Yes…it appears that the medical establishment have known for years that chemotherapy a lot of the time kills patients faster than if they were untreated…what’s more, it worsens a person’s quality of life in which many die directly of the severe effects on the endocrine, immune system and more…cancers often return in more aggressive forms metastasising with an increased risk of apoptosis. In other words it makes things worse whereas there are many natural remedies which not only do no harm but accumulating evidence points to their capacity to fight cancer…some of it is bullshit whilst some holds some truth!! So turning away from toxic treatments that kill towards natural approaches that are showing more hope with the backing of trials kinda reverses the whole argument of this article.”

The comment first annoyed me a bit, of course, but later it made me think and consider the differences between conspiracy theories, assumptions, opinions, evidence and scientific facts. Let’s tackle each of these in turn.


A conspiracy theory is an explanatory or speculative theory suggesting that two or more persons, or an organization, have conspired to cause or cover up, through secret planning and deliberate action, an event or situation typically regarded as illegal or harmful.

Part of the above comment bears some of the hallmarks of a conspiracy theory: “…the medical establishment have known for years that chemotherapy a lot of the time kills patients faster than if they were untreated…” The assumption here is that the conventional healthcare practitioners are evil enough to knowingly do harm to their patients. Such conspiracy theories abound in the realm of alternative medicine; they include the notions that

  • BIG PHARMA is out to kill us all in order to maximize their profits,
  • the ‘establishment’ is suppressing any information about the benefits of alternative treatments,
  • vaccinations are known to be harmful but nevertheless being forced on to our children,
  • drug regulators are in the pocket of the pharmaceutical industry,
  • doctors accept bribes for prescribing dangerous drugs
  • etc. etc.

In a previous blog-post, I have discussed the fact that the current popularity of alternative medicine is at least partly driven by the conviction that there is a sinister plot by ‘the establishment’ that prevents people from benefitting from the wonders of alternative treatments. It is therefore hardly surprising that conspiracy theories like the above are voiced regularly on this blog and elsewhere.


An assumption is something taken for granted or accepted as true without proof.

The above comment continues stating that “…[chemotherapy] makes things worse whereas there are many natural remedies which not only do no harm but accumulating evidence points to their capacity to fight cancer…” There is not proof for these assertions, yet the author takes them for granted. If one were to look for the known facts, one would find the assumptions to be erroneous: chemotherapy has saved countless lives and there simply are no natural remedies that will cure any form of cancer. In the realm of alternative medicine, this seems to worry few, and assumptions of this or similar nature are being made every day. Sadly the plethora of assumptions or bogus claims eventually endanger public health.


An opinion is a judgment, viewpoint, or statement about matters commonly considered to be subjective.

The above comment continues with the opinion that “…turning away from toxic treatments that kill towards natural approaches that are showing more hope with the backing of trials kinda reverses the whole argument of this article.” In general, alternative medicine is based on opinions of this sort. On this blog, we have plenty of examples for that in the comments section. This is perhaps understandable; evidence is usually in short supply, and therefore it often is swiftly replaced with often emotionally loaded opinions. It is even fair to say that much of alternative medicine is, in truth, opinion-based healthcare.


Evidence is anything presented in support of an assertion. This support may be strong or weak. The strongest type of evidence is that which provides direct proof of the truth of an assertion.

One remarkable feature of the above comment is that it is bar of any evidence. In a previous post, I have tried to explain the nature of evidence regarding the efficacy of medical interventions:

The multifactorial nature of any clinical response requires controlling for all the factors that might determine the outcome other than the treatment per se. Ideally, we would need to create a situation or an experiment where two groups of patients are exposed to the full range of factors (e. g. placebo effects, natural history of the condition, regression towards the mean), and the only difference is that one group does receive the treatment, while the other one does not. And this is precisely the model of a controlled clinical trial.

Such studies are designed to minimise all possible sources of bias and confounding. By definition, they have a control group which means that we can, at the end of the treatment period, compare the effects of the treatment in question with those of another intervention, a placebo or no treatment at all.

Many different variations of the controlled trial exist so that the exact design can be adapted to the requirements of the particular treatment and the specific research question at hand. The over-riding principle is, however, always the same: we want to make sure that we can reliably determine whether or not the treatment was the cause of the clinical outcome.

Causality is the key in all of this; and here lies the crucial difference between clinical experience and scientific evidence. What clinician witness in their routine practice can have a myriad of causes; what scientists observe in a well-designed efficacy trial is, in all likelihood, caused by the treatment. The latter is evidence, while the former is not.

Don’t get me wrong; clinical trials are not perfect. They can have many flaws and have rightly been criticised for a myriad of inherent limitations. But it is important to realise that, despite all their short-comings, they are far superior than any other method for determining the efficacy of medical interventions.

There are lots of reasons why a trial can generate an incorrect, i.e. a false positive or a false negative result. We therefore should avoid relying on the findings of a single study. Independent replications are usually required before we can be reasonably sure.

Unfortunately, the findings of these replications do not always confirm the results of the previous study. Whenever we are faced with conflicting results, it is tempting to cherry-pick those studies which seem to confirm our prior belief – tempting but very wrong. In order to arrive at the most reliable conclusion about the efficacy of any treatment, we need to consider the totality of the reliable evidence. This goal is best achieved by conducting a systematic review.

In a systematic review, we assess the quality and quantity of the available evidence, try to synthesise the findings and arrive at an overall verdict about the efficacy of the treatment in question. Technically speaking, this process minimises selection and random biases. Systematic reviews and meta-analyses [these are systematic reviews that pool the data of individual studies] therefore constitute, according to a consensus of most experts, the best available evidence for or against the efficacy of any treatment.


Scientific facts are verified by repeatable careful observation or measurement (by experiments or other means).

Some facts related to the subject of alternative medicine have already been mentioned:

  • chemotherapy prolongs survival of many cancer patients;
  • no alternative therapy has achieved anything remotely similar.

The comment above that motivated me to write this somewhat long-winded post is devoid of facts. This is just one more feature that makes it so typical of the comments by proponents of alternative medicine we see with such embarrassing regularity.

11 Responses to Conspiracy theories, assumptions, opinions, evidence and scientific facts

  • Great post! Unfortunately much of it will not sink in with believers, because they are often reliant on HALF-TRUTHS and GENERALIZATIONS. Your account of conspiracy theory, for example, lists five bullet points we often read in comments on this site. The first three are extreme nonsense, but the last two — “drug regulators are in the pocket of the pharmaceutical industry” and “doctors accept bribes for prescribing dangerous drugs” — may sound reasonable to many people. Read Ben Goldacre’s excellent book Bad Pharma, for example, and you may come away simply accepting statements like this are true.

    But they represent half-truths. Elements within the pharmaceutical industry indeed put pressure and inducements on drug regulators, and a mass of recent reforms of the way the drug companies interact with doctors is evidence that doctors are, and have been, amenable to bribery to prescribe particular drugs. But that does not mean the drugs are “dangerous”, nor that the inducements are invariably successful. Nor, indeed, that they apply to every drug and every doctor: that’s a false generalization. So is a belief that all drugs have massive side-effects and no benefits.

    Similarly for “chemotherapy a lot of the time kills patients faster than if they were untreated.” Anyone who has personally known a cancer patient who reacted badly to chemotherapy and died under treatment might consider that statement to be true. But it is a false generalization. The benefit:risk ratio of chemotherapy for most cancers is clearly favourable. As you succinctly put it: “chemotherapy prolongs survival of many cancer patients.” But it’s hard to accept a statistic when you or your loved one is an exception.

    Your explanation of robust evidence will fall equally on deaf ears. People will argue they don’t need all this ‘artificial’ bobbledy-boo of trials and systematic reviews. They know from their experience that X works. The post hoc ergo propter hoc fallacy has a lot to answer for!

  • On the ‘Big Pharma is out to kill us’ point. This is often pedaled by people that don’t need any kind of medication to live a normal life. I remember going to a Homeopathic doctors in Manchester years ago saying I needed help with asthma which was getting worse and affecting my quality if life. Their reaction was astounding. They said there’s not much they can do, I should have come as a child and then I could have been treated, preventatively. I called this straight away. Faced with a real and serious medical condition they knew they couldn’t do anything. Regression to the mean couldn’t help them and placebo’s can be very dangerous to asthma patients. Anyway, to my point – thanks to real medicine and ‘Big Pharma’, I can completely control my asthma. I play football, run, do HIIT training and mountain biking etc with no symptoms. I get inhalers that are inexpensive, work really well and have no side effects. Thank you Big Pharma

  • Alternative healers often claim that chemotherapy is FORCED on patients. This is not true. When chemotherapy is useful for their type of cancer in their situation it is offered as a treatment option. Advantage/benefits and disadvantage/side effects are explained and discussed. The patient decides if she/he wants the treatment or not. Nobody gets chemotherapy against their wil.

    • No, you are right … it is not “forced” upon people, it is more of a blackmail game than actual force … but the effect is the same. Doctors guilt patients into “choosing” the only “sensible” and “scientifically proven” treatment for their “disease” in front of their family members (they so love bringing in the whole family for their consultations! So just what is the difference? The doctors will condemn and belittle anyone who dares to speak up, against the idiocy of taking a weakened body and pumping it full of poison and radiation.

      And our friend, Frank had this to say …”So is a belief that all drugs have massive side-effects and no benefits.”, which is also laughable … do you watch TV at all, Frank?

      The commercials for big pharma’s dope that is advertised (more proof just how far the establishment will go to bend under for the almighty dollar, who in their right mind would think advertising prescription dope to housewives and the elderly is not completely immoral and unethical?) for IBS, which may cause cramping, abdominal pain, bloating, gas, diarrhea, and constipation ….

      …. let’s say Linzess for example, which is prescribed to “treat” IBS, and has these common side-effects – Abdominal or stomach pain, and severe diarrhea … as well as these uncommon and rare side-effects – heartburn, loss of appetite, nausea, vomiting, weakness, bleeding from the rectum, confusion, loss of bowel control, fainting, difficulty swallowing, shortness of breath –

      So it seems pretty common for you to receive no benefit from the medication at all, due to the common side-effects replicating the original symptoms … and as a bonus, you may be able to pay good money for the privilege of bleeding from the rectum, dealing with confusion, complete loss of bowel control, bouts of fainting, while finding it difficult to swallowing, and suffering from shortness of breath.

      But you are both correct about it not being a conspiracy … a conspiracy by definition is a SECRET plan by a group to do something unlawful or harmful, and there is nothing secret about their plan. There is no money to be made in curing people, the money is made by “treating” their lifelong illnesses … and call me what you will, but I think it is you who is deluding yourself not I … and by all means, take as much of big pharma’s dope as you can while you are still able … you deserve it!

      • @Jack Elmore

        Goodness! You paint a very black picture of medical care.

        You ask if I watch TV at all. Yes, I do, but I live in the UK, not the USA. In this country we have laws absolutely forbidding the advertising of prescription drugs to the public and regulations controlling the claims made for non-prescription medications. The fact that such advertising is permitted to you and your countrymen is something I regard as ethically appalling. You’re dead right: I agree the practice is completely immoral and unethical. But your culture values ‘freedom of speech’ to a quite preposterous extent, of which this is just one example. And I doubt that you’ll see any ban on prescription drug advertising in the near future: you just elected a president who’s on a mission to get rid of all forms of industry regulation, not to increase it.

        As to drug side effects, I think you’ve picked an interesting example. IBS is a poorly understood condition where symptoms fluctuate to quite an extent: the problems are very episodic. Linzess (linaclotide) is intended for IBS patients with constipation, but if it works too successfully, then diarrhoea may be the outcome. It’s indeed interesting that, in common with other gastrointestinal drugs, the most frequent side effects are also gastrointestinal. Linaclotide seems to be very clean for reported side-effects at any other location. Maybe things will improve when drugs can be better tailored to individuals on the basis of pharmacogenomics.

        At least your freedom of speech means that the public is free to report drug effects to the FDA. (We have a similar system in the UK.) Like negative customer reviews on Amazon, this free-for-all system possibly exaggerates problems, but that’s not necessarily a bad thing.

        As for your totally cynical account of the psychological pressures doctors and families put on cancer patients to undergo chemotherapy etc., I’m really disappointed you think that way. I can’t speak for my US clinical friends and colleagues, but I can’t imagine any one of them behaving in the way you describe. You must know doctors with serious personality problems.

        The unarguable fact is that chemotherapy, radiotherapy and surgery have massively reduced death rates from many forms of cancer. If you regard that as less than an achievement that’s your opinion, but it’s not one I can respect. You put “disease” in inverted commas: do you not regard cancer as a disease, Jack? How would you define it, then? Would you rather science didn’t try to find new cures and improve on the old ones? Just give cancer patients sugar pills or stick needles in them and watch them die?

  • Edzard said:

    the ‘establishment’ is suppressing any information about the benefits of alternative treatments,

    I’ve always found it odd that Big Pharma’s influence and power doesn’t seem to extend to taking down youtube videos…

    • What I find curious about Big Pharma is that, despite being so evil and all-powerful, it hasn’t taken over the zero cost / high margin homeopathy market

      • What I find curious about Big Pharma is that, despite being so evil and all-powerful, it hasn’t taken over the zero cost / high margin homeopathy market

        Oh… the market is split and the reason is rather obvious if you think about it. The Big Homeopathy cater to a market niche of gullible consumers who buy anything as long as it is advertised on the packet with a promise of no harmful effects. The problem for Big Pharma is that to meet the requirements to make toxic medicines, they need to employ people who can actually count to more than 200. Such people are usually clever and paid attention in science classes all the way up into university, so they can figure out why and how the medicines actually work, albeit at a cost of side effects of course. All effective medicines also have side effects, thats why you need decades of school to figure out how to prescribe them.
        Anyway… Boiron, Hylands, Ainsworths, Similasan and all the other watershaking companies only need people with strong enough arms who like dressing up in important looking scientist-garb and can learn to bang tap water against a semi soft surface. These workers are genuinely impressed that people want to buy the sugar candy that was scientifically soaked in the banged water and pay ridiculous amounts of money for lactose pills. (read the comments below, they are hilarious)

  • Dear Doctor Ernst
    I have just been listening to you on Radio 4, and am glad to hear such a reasoned, intelligent debate on the subject of Homeopathy. How nice to hear about someone who has held a long term belief but has fought against it in the light of evidence and critical thinking.

    Oddly, you and I find ourselves on opposite sides of the fence, but not over Homeopathy. Over the idea that Big Pharma is out to make money from making people sick and that there is a conspiracy going on.

    Now, before we go any further, I appreciate that the above theories seem mad. I know that. I hear that. I am still seeking, however, an explanation as to why doctors still subscribe to the out dated theory that low fat, high carb diets are good for diabetics, and high fat, low carb diets are fads which will hurt diabetics and are unsustainable. I know you are arguing against homeopathy, but to some extent I can sympathise with the supporters of these conspiracy theories. People have no idea how frustrating it is to see something which works being dismissed by mainstream medication. I think the conspiracy theories are not so much about the fact that there are actually conspiracies. I see this more as a final ‘threat’ – “You won’t believe me, so I will shout conspiracy and then any further arguments from you will be just you defending your friends”.

    May I ask how you stand on this diabetes treatment yourself? And before you answer, yes, I absolutely take drugs to control my blood glucose levels, and yes, no doubt I would be blind/facing amputations/dead from high BG levels without medication. On the other hand, I am on HUGE amounts of medication possibly from spending years following the diet as prescribed by my doctor, and which I abandoned when I was told by my doctor that I was lying about what I ate, because his diet would work otherwise.

    In conclusion, we would welcome all scientific studies on the diet we follow, since HFLC followers see this as a diet which could save people’s lives and make fellow diabetics’ quality of life much better. As a doctor, can you explain why we can’t get science and medicine to stop believing fairy tales and actually look at the evidence? It’s not as if we are experimenting on mice or rats or whatever. We are experimenting with ourselves, 1000’s of willing human subjects with figures to show that this diet works, and yet main stream medicine ignores us in favour of myth and woo-woo.

  • First things first: I’m not only not a doctor, I have no qualifications in medicine whatsoever, and I don’t know anything about diabetes (beyond that it has different types), or know anyone with diabetes. So, without doing extensive research that I don’t currently have the time to, I can’t say anything about the management of diabetes, and I hope you’ll accept my apologies if I accidentally say something blatantly wrong!

    I can, however, think of a few issues surrounding the construction of a study into your diet:

    The first is that, while thousands of people is usually a large number, your study group is entirely self-selected: your cohorts are those diabetics who have abandoned their originally prescribed diets in favour of one like yours and done well. Those who did poorly and returned to their original diet, and any who died, have already been selected out of your group: in essence, you’ve chosen an answer before even setting up to ask the question. (Hopefully no-one did die, but one has to be aware of the possibility: it’s one reason why “miracle cures” for fatal conditions tend to be bandied about so much – a million people might try the “miracle cure”, but you don’t hear from the 999,999 who died, only the one who lived to sing its praises, and that could simply have been because they were the 1 person in 1,000,000 who might be expected to survive having the condition). It may well be that there are a subset of people with your condition who respond well to your diet, but on a planet of seven thousand million people, many of whom have (Wikipedia at the time of writing claims the current figure is ~415 million diabetics globally, and yes, I apologise for using Wikipedia as a source) or will develop diabetes, a few thousand is a very small number (literally around a few millionths of the current diabetics, or a few x 0.0001%). So the existence of your group can only successfully demonstrate that for, say, ~0.0005% of the diabetic population, your diet is non-fatal and potentially beneficial.

    To set up a representative study group, one would need to recruit a large sample of randomly chosen diabetics, and change their diets, and enforce the changes, and monitor their progress over an appropriate length of time. (You’d also ideally want a control group who changed their typical foodstuffs without changing the actual total carb/fat/etc. content of their diets, to avoid picking up effects solely due to lifestyle changes.) Depending on the requirements of the typical diabetic diet, and how important sticking to it is for the _average_ diabetic (remember: I know nothing about diabetes, for which I apologise), this could potentially harm or kill up to the other 99.9995% of the trial population – i.e. up to everyone in the initial trial, which would likely only include perhaps a few hundred random diabetics, and may not include any of your particular subset (depending on the true size of such a subset in the population) at all.

    There could also be further confounding factors in the membership of your group. You’re aware that they exist and have presumably had some form of contact with some of them; therefore, it might be that your group is further self-selected by, for example, being composed almost entirely of English-speakers with Internet access. (It may not, but it’s one possibility.) This biases your population towards the well-off, in particular in America (where the majority of “English”-speaking Internet denizens generally seem to come from) where as I understand it only the well-off can even survive having any sort of chronic condition. Since the financially well-to-do have all manner of other resources to help their survival chances, one can’t even necessarily ascribe such a group’s success to their diets at all.

    For all of these reasons, if such studies into the best diabetic diet for the average diabetic have not as yet been carried out, I can see some pretty good reasons for not wanting to conduct one on humans right now, and would actually recommend conducting them on rats first! (Or another more suitable mammal if rats are a poor model for human diabetes.) If I had the time, I’d investigate the medical databases and try to find out more – have there been any such studies, and if so what their results were, etc. …Another thing that would be interesting, although subject to the confounding factors listed above, might be to compare your group’s mortality rate and age on death (sorry, it’s a morbid study) to those for the wider diabetic population, and see whether members of your group on average survive longer, less long, or about the same. You’d have to find some way of separating out the statistics on your dietary group from everyone else’s, though.

    I’m glad your diet is working for you, and I hope you live a long and happy life! But I hope you see some of the complications of extrapolating from a self-selected sample of even several thousand people, to a population of several hundred million. (And I completely sympathise with the impulse you describe to cry conspiracy. ^^’ It’s much more comfortable to have an in-group that means well and an out-group that means harm than to be constantly juggling conflicting good intentions on all sides.) Finally, once again, I apologise for anything incorrect or irrelevant that I’ve said!

    • Science these days is severely flawed, and only getting worse … the information is out there, you do not have to shoot arrows at the moon!!

      Peer review: a flawed process at the heart of science and journals

      Peer review is at the heart of the processes of not just medical journals but of all of science. It is the method by which grants are allocated, papers published, academics promoted, and Nobel prizes won. Yet it is hard to define. It has until recently been unstudied. And its defects are easier to identify than its attributes. Yet it shows no sign of going away. Famously, it is compared with democracy: a system full of problems but the least worst we have.

      So we have little evidence on the effectiveness of peer review, but we have considerable evidence on its defects. In addition to being poor at detecting gross defects and almost useless for detecting fraud it is slow, expensive, profligate of academic time, highly subjective, something of a lottery, prone to bias, and easily abused……..

      So peer review is a flawed process, full of easily identified defects with little evidence that it works. Nevertheless, it is likely to remain central to science and journals because there is no obvious alternative, and scientists and editors have a continuing belief in peer review. How odd that science should be rooted in belief.

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