The trouble with herbals

October 6th, 2007 by Ben Goldacre in bad science, herbal remedies | 103 Comments »

Ben Goldacre
The Guardian
Saturday October 6 2007

The news this week that herbal remedies can be ineffective or dangerous is boring: but come with me on a journey through time (time… time…) to the origins of medicine.

Herbs contain bioactive compounds. That’s why they can be effective, but it’s also why they can have side effects (some will inactivate your contraceptive pill, others will cause renal failure). Huge numbers of bioactive compounds extracted or derived from plants are used today in medical practice, including even common stuff like aspirin. There is little difference between herbal medicine and medicine in terms of what is used, only in how.

Digoxin in foxglove is very good at treating atrial fibrillation, a common kind of irregular heart movement. Unfortunately the dose range is very narrow, so it’s really quite easy to kill your patient. From the moment of its discovery, pharmacologists worked hard to standardise the dose.

They started with standardised preparations of the plant, but this proved dangerously inconsistent, because the quantity of the active component in foxglove was so variable, so new strategies were developed: standardised preparations of each batch of plant were tested in animals first, to work out how potent they were, and so on. Eventually we worked out how to extract the digitalis, and it could be weighed out.

Now people do careful studies of large numbers of patients on digoxin to see which dose is most beneficial, to understand how it works, and careful monitoring of side effects takes place, from individual clinicians writing about their concerns in medical journals all the way up to the yellow card system, where doctors and even patients can send in their concerns to the MHRA, however trivial or unproven they may be.

This process of enquiry, and standardisation, and testing, and verification, and negative findings, and dismissal of ineffective methods, and more, is one of the great developments in medical and intellectual history. Many people were disappointed along the way, as their ideas and theories were proved to be unfounded. Digoxin pills and foxglove both contain the same ingredient, but it is how they are managed and handed over that differs.

Until a herbal practitioner can show that giving a whole plant instead of an extract really is better, they’re making stuff up when they make those claims. Similarly, until they can show that using herbs at such low doses that they have no measurable effect is somehow beneficial, beyond the placebo (and placebo is great by the way) then they’re shooting with the stars.

But there are structural problems in the way that herbalists work: they have failed – over millennia – to collectivise, so they do not work together on research, but rather as independent commercial traders. They do not move to university settings, where the culture of critical self-appraisal might infect them, and possibly extinguish them too, if their ideas don’t stand up.

And where alternative therapists do move into universities, they wall themselves off from the most valuable influences. CAM therapists don’t rub shoulders with colleagues from other disciplines, who could share ideas and insights with them, and move ideas forward, or help brush the bad ones aside. The alternative medicine university courses I have approached have simply, flatly, refused to tell me the most basic things, like what they teach and how.

It’s because of this culture, not funding, that the “research” on herbal remedies is inadequate. Huge numbers of “trials” are produced, at great expense, but the trials are inept, they are not “fair tests”, they have inadequate “blinding” and “randomisation”, positive results alone are “cherry-picked”, and worse.

An inept trial, bound by design to give a false positive result, costs just as much as a fair test of a treatment. And these problems are endemic: one study looked at the entire cannon of research on traditional Chinese medicine, and found 1100 papers: not one single trial published in China, in the entire history of research into traditional treatments, had ever found a test treatment to be ineffective. Not a single one.

Herbal pills contain bioactive compounds which can have real effects, but it is these differences of style, not content, that divide alternative therapies from medicine: and it will ever be the same.

References:

Do certain countries produce only positive results? A systematic review of controlled trials.
Vickers A, Goyal N, Harland R, Rees R.
Control Clin Trials. 1998 Apr;19(2):159-66.

A systematic review of randomised clinical trials of individualised herbal medicine in any indication
R Guo, P H Canter, and E Ernst
Postgrad. Med. J., Oct 2007; 83: 633 – 637.


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103 Responses



  1. secondfresh said,

    October 8, 2012 at 1:19 am

    Hi Ben and all!

    I haven’t read through this blog for a while but I saw Ben’s fascinating TED talk on the problems with publication in evidence-based medicine and remembered how much I loved visiting this site.

    I have a very keen interest in integrative medicine, including herbal therpy, and should mention from the outset that I have worked with clients/businesses that are on either side of the wider health care industry, that is, with Pharmaceutical companies and also with an integrative practitioner – and both have solutions or exciting prospects but are riddled with problems. My background is in science so obviously I like the idea of everything having proof, and to some extent both sides of the industry have proof – and have a lot lacking. From the 20 or so comments I read through here I can see that many would agree.

    I’m from Australia and from what I’ve heard the UK has a better reputation in healthcare than over here, but one of the big problems I have seen and discussed over this side of the world with many people (talking hundreds not tens) is the lack of care and time given by various professions in seeing and listening to a patient.

    So what does this have to do with herbal remedies?

    I think good clinicians – whether conventional or integrative will get results, even extreme alternative medicine practices or a friendly face handing out sugar pills is bound to do something (as Ben mentions – the placebo effect is indeed an effect). To be honest I don’t see the difference between a doctor using an SSRI or a herbalist using St John’s Wort as an antidepressant (seems to be the first example that comes to mind for many) both are offering the patient something that there is evidence for using. However, the important part is in the follow up, is in going on the journey with the patient to get to the bottom of the problem – to look at the individual patient, their history, their bloods and physiology then looking at the tools available to treat them. All practitioners exercise faith in their chosen solution since there is indeed problems with evidence in both fields and since each individual is different – there is always a chance that a proven solution won’t work for the person sitting in front of you.

    I think a bigger danger is when there is a war between the medical doctor and the herbal therapist. First lets consider the doctor who is at war with the herbal therapist – regardless of whether or not practitioners are practicing responsibly, patients will still go to see them – in fact, whether something has any basis for use or not, people will still try it, often forking out large amounts of money to the “practitioners” of the “art” in the process (psychics are the first thing that come to mind here). So if we face the fact that people will always go looking for answers that may or may not have the proof to back them up and instead look for ways in which a patient can be guided down wiser paths of treatment, or, in the case of the expensive placebo, maybe excepting this as their choice instead of bullying them or scaring them to try to persuade them to do exactly as you would have them do and try to work with it instead, would this not be more beneficial for the patient? Surely these scare tactics push patients towards not disclosing alternative treatments in the future or seeking someone else’s advice? Looking at it the other way around, I think it is clear why herbal therapists should not be at war with doctors – I don’t think I need to spell it out.

    As far as my experience goes personally, I have been diagnosed with “Major depression” a couple of times – in one of my earlier episodes I considered trying conventional antidepressants and thought to use St John’s Wort first – it didn’t work quickly so I asked to try another liquid herbal remedy – it was a mixture of Skullcap, Peonia and Withania (they have such weird names…) and this time “it” worked…I’m a sample of one so it could have been chance, but I didn’t care because I felt good and was not stuck taking an SSRI for months, which was good not just because of the associated risks of SSRIs, but also because I’m terrible at remembering to take something! The most recent time I’ve had depression, the herbal mixture that worked before didn’t, instead a mixture of St John’s Wort and Peonia made me feel much better, again this could have been a combination of placebo and chance, but I didn’t care, I felt good within about an hour each time I took a few mls of the liquid and that’s all that mattered for me.

    Of course, if these turned out to be harmful substances that caused serious side effects and other problems, I’d want to know about it and I think it would be great if herbal therapists conducted proper clinical trials on what they use. In my case, the fact was that I knew more about the problems with conventional antidepressants than I did about herbal remedies, so I went with what I considered a preferred first port of call. My doctor knew and I always had the conventional option up my sleeve if the herbs didn’t work. My herbal therapist “treated” me and that was that.

    Sorry that was a lot of ranting but one more thing I would like to say:

    I work with an integrative practitioner at the moment and for a long time now I have suggested that we conduct a clinical study on some of the remedies that she has found to benefit many of her patients – the problem is it seems impossible to use her treatments in its entirety whilst conducting a study and she feels as though it would be doing a disservice to her patients. Plus, if she did not use the combination of isolates, liquid herbs and vitamin supplements to treat the problem, then it’s not really a reflection of what we’re finding in the clinic – that patients that see her get results (I won’t go into the specifics but the results are measured and tracked, it’s not something that depends on a survey of “yes I feel better” etc. ). So far I have not been able to think of a way that we could conduct a good and worthwhile study that is able to look at the entire treatment approach rather than a single herb at a time. The treatment regime is so specific to each person that it couldn’t be standardised without actually changing the treatment. The reasons for conducting the research would be to show an effect a result, and if we look at the complexity of physiology and biochemistry, it makes sense to use a range of remedies that act in concert to manage and treat patients.

    I’m really open to criticism and help here, I would love to be able to be part of working towards better practices within herbal medicine (though I am not a practitioner myself) but I can’t really see actual solutions. Maybe that’s because I’m young and shortsighted – so please, wiser and more experienced words would be very much welcome :)

  2. Sanchia said,

    May 4, 2014 at 7:39 pm

    I always wonder if herbal remedies aren’t given too much praise in todays day and age. Sure they can be helpful when you have trouble sleeping or even a bit of indigestion. Traditional healers that use herbal remdies are always a controversial topic in South Africa and there is regularly stories on the news of people, even young children, who have been killed through herbal remedies.

  3. Matthew Lundquist said,

    June 23, 2014 at 12:52 am

    Ben Goldacre,

    This is a recent in-depth critique of your articles relating to ”complementary and lifestyle” medicine. Please read carefully and write any counter-arguments to the critique here.

    objectiveskeptic20.blogspot.co.uk/2014/06/david-robert-grimes-ben-goldacre.html

    I await your counter-arguments…