On this blog, I have repeatedly tried to alert consumers and patients to the risks of herbal medicine. The risks include:
- toxicity of one or more ingredients of the plant,
- interactions with other medicines,
- contamination with toxic non-herbal substances such as heavy metals,
- adulteration with synthetic drugs such as steroids,
- ineffectiveness in treating the target disease
- reduction of adherence to prescribed medicines.
A new paper throws more light on the latter issue which has been not well-studies so far.
The objective of this study was to investigate the relationship between the use of medicinal plants and medication adherence in elderly people. The authors conducted an observational, cross-sectional study of elderly residents in Cuité-PB, Northeastern Brazil, through a household survey. A stratified proportional and systematic random sample of 240 elders was interviewed in their homes and the use of pharmaceutical medicines and of medicinal plants was assessed by direct examination. The association of medication adherence with socio-demographic, clinical, medication and use of medicinal plants was analysed with multiple logistic regression.
The results showed that medication non-adherence increases with use of herbal medicines (adjusted odds ratio 2.022, 95% CI 1.059–3.862, p = 0.03), as well as with the number of different medicinal plants used (adjusted odds ratio 1.937, 95% CI 1.265–2.965, p = 0.002).
The authors concluded that this study provides first-hand evidence that the use of herbal medicines is associated with poor medication adherence. Given the high frequency of the use of herbal medicines, further research into the mechanisms of this association is justified.
This conclusion is well-put, I think. If these findings are confirmed in other populations, we are confronted with a somewhat paradoxical situation: combining herbal and synthetic medicines can reduce adherence to the synthetic drugs and, in cases where adherence is not affected, it could increase the risk of herb/drug interactions.
Don’t get me wrong, I have nothing against systematic reviews. Quite to the contrary, I am sure they are an important source of information for patients, doctors, scientists, policy makers and others – after all, I have published more than 300 of such papers!
Having said that, I do dislike a certain type of systematic review, namely systematic reviews by Chinese authors evaluating TCM therapies and arriving at misleading conclusions. Such papers are currently swamping the marked.
At first glance, they look fine. On closer scrutiny, however, most turn out to be stereotypically useless, boring and promotional. The type of article I mean starts by stating its objective which usually is to evaluate the evidence for a traditional Chinese therapy as a treatment of a condition which few people in their right mind would treat with any form of TCM. It continues with details about the methodologies employed and then, in the results section, informs the reader that x studies were included in the review which mostly reported encouraging results but were wide open to bias. And then comes the crucial bit: THE CONCLUSIONS.
They are as predictable as they are misleading. let me give you two examples only published in the last few days.
The first review drew the following conclusions: This systematic review suggests that Chinese Herbal Medicine as an adjunctive therapy can improve cognitive impairment and enhance immediate response and quality of life in Senile Vascular Dementia patients. However, because of limitations of methodological quality in the included studies, further research of rigorous design is needed.
The second review concluded that the evidence that external application of traditional Chinese medicine is an effective treatment for venous ulcers is encouraging, but not conclusive due to the low methodological quality of the RCTs. Therefore, more high-quality RCTs with larger sample sizes are required.
Why does that sort of thing frustrate me so much? Because it is utterly meaningless and potentially harmful:
- I don’t know what treatments the authors are talking about.
- Even if I managed to dig deeper, I cannot get the information because practically all the primary studies are published in obscure journals in Chinese language.
- Even if I did read Chinese, I do not feel motivated to assess the primary studies because we know they are all of very poor quality – too flimsy to bother.
- Even if they were formally of good quality, I would have my doubts about their reliability; remember: 100% of these trials report positive findings!
- Most crucially, I am frustrated because conclusions of this nature are deeply misleading and potentially harmful. They give the impression that there might be ‘something in it’, and that it (whatever ‘it’ might be) could be well worth trying. This may give false hope to patients and can send the rest of us on a wild goose chase.
So, to ease the task of future authors of such papers, I decided give them a text for a proper EVIDENCE-BASED conclusion which they can adapt to fit every review. This will save them time and, more importantly perhaps, it will save everyone who might be tempted to read such futile articles the effort to study them in detail. Here is my suggestion for a conclusion soundly based on the evidence, not matter what TCM subject the review is about:
OUR SYSTEMATIC REVIEW HAS SHOWN THAT THERAPY ‘X’ AS A TREATMENT OF CONDITION ‘Y’ IS CURRENTLY NOT SUPPORTED BY SOUND EVIDENCE.
The search for an effective treatment of obesity is understandably intense. Many scientists are looking in the plant kingdom for a solution, but so far none has been forthcoming – as we have already discussed on this blog before (e. g. here, and here). One herbal slimming aid is currently becoming popular: Yerba Mate also called Ilex paraguariensis, a plant many of us know from teas and other beverages. Our review concluded that the evidence for it was unconvincing but that it merited further study. This was 10 years ago, and meanwhile the evidence has moved on.
The aim of a recent study was to investigate the efficacy of Yerba Mate supplementation in subjects with obesity. For this purpose, a randomized, double-blind, placebo-controlled trial was conducted. Korean subjects with obesity (body mass index (BMI) ≥ 25 but < 35 kg/m(2) and waist-hip ratio (WHR) ≥ 0.90 for men and ≥ 0.85 for women) were given oral supplements of Yerba Mate capsules (n = 15) or placebos (n = 15) for 12 weeks. They took three capsules per each meal, total three times in a day (3 g/day). Outcome measures were efficacy (abdominal fat distribution, anthropometric parameters and blood lipid profiles) and safety (adverse events, laboratory test results and vital signs).
During 12 weeks of Yerba Mate supplementation, statistically significant decreases in body fat mass and percent body fat compared to the placebo group were noted significant. The WHR was significantly also decreased in the Yerba Mate group compared to the placebo group. No clinically significant changes in any safety parameters were observed.
The authors concluded that Yerba Mate supplementation decreased body fat mass, percent body fat and WHR. Yerba Mate was a potent anti-obesity reagent that did not produce significant adverse effects. These results suggested that Yerba Mate supplementation may be effective for treating obese individuals.
These are encouraging results, but the conclusions go way too far, for my taste. The study was tiny and does therefore not lend itself to far-reaching generalisations. What would be helpful, is a review of other evidence. As it happens, such a paper has just become available. Its authors evaluated the impact of yerba maté on obesity and obesity-related inflammation and demonstrate that yerba maté suppresses adipocyte differentiation as well as triglyceride accumulation and reduces inflammation. Animal studies show that yerba maté modulates signaling pathways that regulate adipogenesis, antioxidant, anti-inflammatory and insulin signaling responses.
The review authors concluded that the use of yerba maté might be useful against obesity, improving the lipid parameters in humans and animal models. In addition, yerba maté modulates the expression of genes that are changed in the obese state and restores them to more normal levels of expression. In doing so, it addresses several of the abnormal and disease-causing factors associated with obesity. Protective and ameliorative effects on insulin resistance were also observed… it seems that yerba maté beverages and supplements might be helpful in the battle against obesity.
I am still not fully convinced that this dietary supplement is the solution to the current obesity epidemic. But the evidence is encouraging – more so than for most of the many other ‘natural’ slimming aids that are presently being promoted for this condition by gurus like Dr Oz.
What we needed now is not the ill-informed, self-interested voice of charlatans; what we need is well-designed research to define efficacy, effect size and risks.
The Nobel Prize committee has just awarded this year’s prize to a Chinese researcher from the Chinese Academy of Traditional Chinese Medicine (TCM) in Beijing. To be precise, the 2015 Nobel Prize in Physiology or Medicine was given jointly to three scientists from three different institutions, William C. Campbell, Satoshi Ōmura and Youyou Tu, for their work on new anti-malaria drugs. A small excerpt from the press-release of the committee tells us more about the possibility of a TCM connection:
Malaria was traditionally treated by chloroquine or quinine, but with declining success. By the late 1960s, efforts to eradicate Malaria had failed and the disease was on the rise. At that time, Youyou Tu in China turned to traditional herbal medicine to tackle the challenge of developing novel Malaria therapies. From a large-scale screen of herbal remedies in Malaria-infected animals, an extract from the plant Artemisia annua emerged as an interesting candidate. However, the results were inconsistent, so Tu revisited the ancient literature and discovered clues that guided her in her quest to successfully extract the active component from Artemisia annua. Tu was the first to show that this component, later called Artemisinin, was highly effective against the Malaria parasite, both in infected animals and in humans (Figure 4). Artemisinin represents a new class of antimalarial agents that rapidly kill the Malaria parasites at an early stage of their development, which explains its unprecedented potency in the treatment of severe Malaria.
One does not have to be a clairvoyant to predict that this event will now be celebrated by TCM fans as a vindication of TCM. But is this justified?
The antifebrile effect of the Chinese herb Artemisia annua (qinghaosu 青蒿素), or sweet wormwood, has been known 1,700 years ago. Tu was the first to extract the biologically active component of the herb, Artemisinin, and discover how it worked. As a result, Artemisinin could be studied and tested for efficacy. Fortunately these tests turned out positive, and subsequently Artemisinin could be produced on a large scale and made available for those who needed it.
Tu’s achievements are huge, and I do unreservedly and enthusiastically applaud her for getting this prestigious award. But is it an award for TCM?
One could even argue that Tu showed how insufficient TCM can be. Artemisia was not used for malaria in TCM, it was used to lower fever. In fact, the whole plant extract shows not enough activity to be effective for malaria. It was not employed to treat a disease but to ease a symptom. TCM physicians had no idea what malaria was, what its cause was, or how it should be treated effectively. It needed a skilled scientist, modern scientific tools and systematic research to make these discoveries.
So, what does this episode really tell us?
Amongst other things,I think, it shows that medicine is open to discoveries regardless where they come from, that experience alone is normally insufficient to make progress, that China has some good scientists who can do amazing work, that plants contain millions of interesting molecules of which some might be therapeutic, that tenacity and skill is usually required to make an important break-through… WHAT IS DOES NOT SHOW, HOWEVER, IS THAT THE MERITS OF TCM HAVE BEEN AKNOWLEDGED BY A NOBEL PRIZE.
Proponents of alternative medicine regularly stress the notion that their treatments are either risk-free or much safer than conventional medicine. This assumption may be excellent for marketing bogus treatments, however, it neglects that even a relatively harmless therapy can become dangerous, if it is ineffective. Here is yet again a tragic reminder of this undeniable fact.
Japanese doctors reported the case of 2-year-old girl who died of precursor B-cell acute lymphoblastic leukaemia (ALL), the most common cancer in children.
She had no remarkable medical history. She was transferred to a hospital because of respiratory distress and died 4 hours after arrival. Two weeks before her death, she had developed a fever of 39 degrees C, which subsided after the administration of a naturopathic herbal remedy. One week before death, she developed jaundice, and her condition worsened on the day of death.
Laboratory test results on admission to hospital showed a markedly elevated white blood cell count. Accordingly, the cause of death was suspected to be acute leukaemia. Forensic autopsy revealed the cause of death to be precursor B-cell ALL.
With the current advancements in medical technology, the 5-year survival rate of children with ALL is nearly 90%. However, in this case, the child’s parents had opted for naturopathy instead of evidence-based medicine. They had not taken her to a hospital for a medical check-up or immunisation since she was an infant. If the child had received routine medical care, she would have a more than 60% chance of being alive 5 years after diagnosis of ALL.
The authors of this case-report concluded that the parents should be accused of medical neglect regardless of their motives.
Such cases are tragic and infuriating in equal measure. There is no way of knowing how often this sort of thing happens; we rely entirely on anecdotes because systematic research is hardly feasible.
While anecdotes of this nature have their obvious limitations, they are nevertheless important. They can serve as poignant reminders that alternative remedies might be relatively harmless, but this does not necessarily apply to all alternative practitioners. Moreover, they should make us redouble our efforts to inform the public responsibly about the all too often trivialized risks of alternative medicine.
This post is dedicated to all homeopathic character assassins.
Some ardent homeopathy fans have reminded me that, some 25 years ago, I published (OH, WHAT A SCANDAL!!!) a positive trial of homeopathy; I even found a website that proudly announces this fact. Homeopaths seem jubilant about this discovery (not because they now need to revise their allegations that I never did any trials; or the other, equally popular claim, that I have always been squarely against their trade but) because the implication is that even I have to concede that homeopathic remedies are better than placebo. In their view, this seems to beg the following important and embarrassing questions:
- Why did I change my mind?
- Am I not contradicting myself?
- Who has bribed me?
- Am I in the pocket of Big Pharma?
- Does this ‘skeleton in my closet’ discredit me for all times?
I remember the trial in question quite well. We conducted it during my time in Vienna, and I am proud of several innovative ideas that went into it. Here is the abstract in full:
The aim of this study was to test the effectiveness of a combined homeopathic medication in primary varicosity. A well-defined population of 61 patients was randomized into active medication (Poikiven®) or placebo. Both were given for 24 d. At the start of the trial, after 12 d medication and at the end of the study, objective and subjective parameters were recorded: venous filling time, leg volume, calf circumference, haemorheological measurements and patients’ symptoms such as cramps, itching, leg heaviness, pain during standing and the need to elevate the legs. The results show that venous filling time is changed by 44% towards normal in the actively-treated group. The average leg volume fell significantly more in this group, but calf circumferences did not change significantly and blood rheology was not altered in any relevant way. None of the patients reported side-effects. Subjective complaints were relieved significantly more by Poikiven than by placebo. These results suggest that the oral treatment of primary varicosity using Poikiven is feasible.
So, there we have it: a homeopathic remedy (as tested by me) is clearly better than placebo normalising important objective parameters as well as subjective symptoms of varicose veins. Is that not a contradiction of what I keep saying today, namely that homeopathy is a placebo therapy?
YES AND NO! (But much more NO than YES)
Yes, because that was clearly our result, and I never tried to deny it.
No, because our verum was far from being a homeopathic, highly diluted remedy. It contained Aesculus D1 12,5 ml, Arnica D1 2,5 ml, Carduus marianus D1 5 ml, Hamamelis D1 10 ml, Lachesis D6 5 ml, Lycopodium D4 5 ml, Melilotus officinalis D1 10 ml. Take just the first of these ingredients, Aesculus or horse chestnut. This is a herbal medicine that has been well documented (even via a Cochrane review) to be effective for the symptoms of varicose veins, and it contains Aesculus in the D1 potency. This means that it is diluted merely by a factor of 1:10. So, for all intents and purposes, our verum was herbal by nature, and there is no surprise at all that we found it to be effective.[Here is a little ‘aside’: Aesculus is a proven treatment for varicose veins. Homeopathy must always rely on the ‘like cures like’ principle. Therefore, if Aesculus had been used in the homeopathic way, would it not, according to homeopathic dogma, had to worsen the symptoms of our patients rather than alleviating them?]
All of this would be trivial to the extreme, if it did not touch upon an important and confusing point which is often used as an ‘escape route’ by homeopaths when they find themselves between a rock and a hard place. Some trials of homeopathy are positive because they use medications which are homeopathic only by name. This regularly creates considerable confusion. In the recent BMJ debate I tried to address this issue head on by stating at the outset: ” Nobody questions, of course, that some substances used in homeopathy, such as arsenic or strychnine, can be pharmacologically active, but homeopathic medicines are typically far too dilute to have any effect.”
And that’s the point: homeopathic remedies beyond a C12 potency contain nothing, less dilute ones contain little to very little, and D1 potencies are hardy diluted at all and thus contain substantial amounts of active ingredients. Such low potencies are rarely used by homeopaths and should be called PSEUDO-HOMEOPATHIC, in my view. Homeopaths tend to use this confusing complexity to wriggle out of difficult arguments, and often they rely on systematic reviews of homeopathic trials which can generate somewhat confusing overall findings because of such PSEUDO-HOMEOPATHIC remedies.
To make it perfectly clear: the typical homeopathic remedy is far too dilute to have any effect. When scientists or the public at large speak of homeopathic remedies, we don’t mean extracts of Aesculus or potent poisons like Arsenic D1 (has anyone heard of someone claiming to have killed rats with homeopathy?); we refer to the vast majority of remedies which are highly dilute and contain no or very few active molecules – even when we do not explain this somewhat complicated and rather tedious circumstance each and every time. I therefore declare once and for all that, unless I indicate otherwise, I do NOT mean potencies below C6 when I speak of a ‘homeopathic remedy’ (sorry homeopathy fans, perhaps I should have done this when I started this blog).
What if our Vienna study all those years ago had tested not the pseudo-homeopathic ‘Poikiven’ but a highly dilute, real homeopathic remedy and had still come up with a positive finding? Would that make me inconsistent, dishonest, untrustworthy or corrupt? Certainly not!
I have always urged people to not go by the results of single trials. There are numerous reasons why a single study can produce a misleading result. We should therefore, wherever possible, rely on systematic reviews that critically evaluate the totality of the evidence (I would always mistrust even my own trial data, if it contradicted the totality of the reliable evidence) – and such analyses clearly fail to show that homeopathy is more than a placebo.
And even, if none of this had happened, and I had just changed my mind about homeopathy because
- the evidence changed,
- I had become wiser,
- I had learnt how to think like a scientist,
- I had managed to see behind the smokescreen many homeopaths put up to hide the truth?
Would that discredit me? I don’t think so! As someone once said, being able to change one’s mind is a sign of intelligence.
I am sure that the weird world of homeopathic character assassination will soon find something else to discredit me – but for now…
I REST MY CASE.
Lots of alternative therapies are advocated for migraine. Few of them are supported by good evidence. An exception could be the herbal remedy FEVERFEW.
This review is an update of a previously published review in the Cochrane Database of Systematic Reviews on ‘Feverfew for preventing migraine’. Feverfew (Tanacetum parthenium L.) extract is a herbal remedy, which has been used for preventing attacks of migraine. Our aim was to systematically review the evidence from double-blind, randomised, clinical trials (RCTs) assessing the clinical efficacy and safety of feverfew monopreparations versus placebo for preventing migraine.
For this updated version of the review we searched CENTRAL, MEDLINE, EMBASE and AMED to January 2015. We contacted manufacturers of feverfew and checked the bibliographies of identified articles for further trials.
We included randomised, placebo-controlled, double-blind trials assessing the efficacy of feverfew monopreparations for preventing migraine in migraine sufferers of any age. We included trials using clinical outcome measures, while we excluded trials focusing exclusively on physiological parameters. There were no restrictions regarding the language of publication.
We systematically extracted data on patients, interventions, methods, outcome measures, results and adverse events. We assessed risk of bias using the Cochrane ‘Risk of bias’ tool and evaluated methodological quality using the Oxford Quality Scale developed by Jadad and colleagues. Two review authors independently selected studies, assessed methodological quality and extracted data. We resolved disagreements concerning evaluation of individual trials through discussion.
We identified one new study for this update, resulting in a total of 6 trials (561 patients) meeting the inclusion criteria. Five of the 6 trials reported on the main outcome measure which was migraine frequency. Although 5 of the trials were generally of good methodological quality, all studies were either of unclear or high risk of bias with regards to sample size. Pooled analysis of the results was not possible due to the lack of common outcome measures and heterogeneity between studies in terms of participants, interventions and designs. The most recent trial added to this update was rigorous and larger (n = 218) than previous studies. It used a stable feverfew extract at a dose determined by a previous dose-finding trial. It reported that feverfew reduced migraine frequency by 1.9 attacks from 4.8 to 2.9 and placebo by 1.3 from to 4.8 to 3.5 per month. This difference in effect between feverfew and placebo was thus 0.6 attacks per month. For the secondary outcome measures such as intensity and duration of migraine attacks, incidence and severity of nausea and vomiting, and global assessment no statistically significant differences between feverfew and placebo were reported.
The results of previous trials were not convincing: three trials reporting positive effects of feverfew were all of small sample size (17 to 60 participants), while two rigorous trials (n = 50, 147) did not find significant differences between feverfew and placebo.
Only mild and transient adverse events of feverfew, most commonly gastrointestinal complaints and mouth ulcers, were reported in the included trials.
We concluded that, since the last version of this review, one larger rigorous study has been included, reporting a difference in effect between feverfew and placebo of 0.6 attacks per month. This adds some positive evidence to the mixed and inconclusive findings of the previous review. However, this constitutes low quality evidence, which needs to be confirmed in larger rigorous trials with stable feverfew extracts and clearly defined migraine populations before firm conclusions can be drawn. It appears from the data reviewed that feverfew is not associated with any major safety concerns.
So, good or bad news for migraine sufferers? I suppose it depends on whether you are an optimist or a pessimist. I would say that, considering the mostly bad news about alternative medicine for migraine, it is relative good news: patients who want to try something ‘natural’ could do so, particularly in view of the lack of serious risks.
I have repeatedly stressed that herbal remedies can cause harm in a range of ways. Indian rheumatologists recently enforced this point by publishing a case-report of adrenal suppression caused by herbal remedies.
A 49-year-old male presented with polyarthritis from which he had suffered for more than 10 years. His serum cortisol levels were extremely low, he had vitamin D deficiency, and his rheumatoid factor was negative. He revealed symptoms of adrenal suppression, mainly muscle weakness and suicidal tendency, and few other psychiatric disturbances.
The patient eventually discontinued his herbal medicine. Then, he was put on deflazacort for 12 weeks at 12 mg twice daily and later the dose was tapered to 6 mg/day. Deflazocort, an intermediate-acting corticosteroid, was prescribed to minimize the probable withdrawal symptoms due to the probable presence of dexamethasone or betamethasone (long-acting steroids) presumably from the herbal medication.
The herbal samples of used by the patient was analysed by mass spectrometry. It showed the presence of steroidal compounds by the mass 393.81, which may be dexamethasone or betamethasone.
The authors of this paper believe that the symptoms of adrenal suppression could have precipitated or exacerbated the neuropsychiatric disturbances due to Hypothalamus-Pituitary-Adrenal (HPA) suppression. In their view, adrenal suppression following ingestion of herbal remedies is of major concern. Abrupt withdrawal of such products could precipitate adrenal failure which can be fatal.
It should be added, I think, that such illegal adulterations of herbal remedies have been reported with some regularity, particularly in Indian (and Chinese) preparations. Our systematic review showed that this problem has caused serious harm. The most severe documented adverse effects include agranulocytosis, meningitis, multi-organ failure, perinatal stroke, arsenic, lead or mercury poisoning, malignancies or carcinomas, hepatic encephalopathy, hepatorenal syndrome, nephrotoxicity, rhabdomyolysis, metabolic acidosis, renal or liver failure, cerebral edema, coma, intracerebral haemorrhage, and death.
As under-reporting can be suspected to be huge, we do currently not know how frequent these events are.
There are things that cannot be said too often. In medicine, these are often related to issues that can save lives. In alternative medicine, it is worth remembering that there is nothing that can save more lives than the following rule: EVEN AN APPARENTLY HARMLESS REMEDY WILL BECOME LIFE-THREATENING, IF IT IS USED AS AN ALTERNATIVE TO AN EFFECTIVE THERAPY FOR A SERIOUS CONDITION.
Here is a publication that serves as a very sad reminder of this important axiom.
Japanese physicians recently published a case-report of 2-year-old girl who died of precursor B-cell acute lymphoblastic leukaemia (ALL), the most common cancer in children. She had no remarkable medical history. She was transferred to a hospital because of respiratory distress and died 4 hours after arrival.
Two weeks before her death, she had developed a fever of 39°C, which subsided after the administration of a naturopathic herbal remedy. Subsequently, she developed jaundice one week before death, and her condition worsened on the day of death.
Laboratory test results on admission showed a markedly elevated white blood cell count. Accordingly, the cause of death was suspected to be acute leukaemia. Forensic autopsy revealed the cause of death to be precursor B-cell ALL.
With advancements in medical technology, the 5-year survival rate of children with ALL is nearly 90%. However, in this case, the deceased’s parents preferred alternative medicine to evidence-based medicine and had not taken her to a hospital for a medical check-up or immunisation since she was an infant. The authors state that, if she had received routine medical care, she would have a more than 60% chance of being alive 5 years after diagnosis. Therefore, we conclude that the parents should be accused of medical neglect regardless of their motives.
Alternative practitioners who treat their patients in this way, are in my experience often full of good intentions. They remind me of something Bert Brecht one wrote: THE OPPOSITE OF GOOD IS NOT EVIL, IT IS GOOD INTENTIONS.
One of the UK’s most ardent promoters of outright unproven and disproven therapies must be Dr Michael Dixon. He has repeatedly and deservedly received a mention on this blog. Steven Novella even called him once a ‘pyromaniac in a field of (integrative) straw men’. This is because Steven felt that Dixon uses phony arguments to promote dodgy therapies. If you find this hard to believe (after all Dixon is a GP who heads important organisations such as the NHS Alliance and the College of Medicine), just look at him dabbling in spiritual healing. Unusual, to say the least, I’d say. If you want to learn more about the strange Dr Dixon, you should read my memoir where he makes several remarkable appearances.
I always delight when I stumble over something that one of my former co-workers (yes, Dixon and I did collaborate for many years) has said to the press. This is why an otherwise silly article in the Daily Mail (yes, I know!) caught my attention; here is the relevant section: Dr Mike Dixon, a GP in Cullompton, Devon, and chairman of the College of Medicine, says he is a ‘fan’ of herbal medicines because they are ‘safe, help to encourage self-care by patients and, in cases such as mint and aloe vera, can be grown by the patients themselves, making them virtually free’.
As I already pointed out, Dixon does tend to promote bizarre concepts. The generalisation that herbal remedies are safe is not just bizarre, it also put the public at risk. One does not need to search long to find an article that makes this clear:
Various reports suggest a high contemporaneous prevalence of herb-drug use in both developed and developing countries. The World Health Organisation indicates that 80% of the Asian and African populations rely on traditional medicine as the primary method for their health care needs. Since time immemorial and despite the beneficial and traditional roles of herbs in different communities, the toxicity and herb-drug interactions that emanate from this practice have led to severe adverse effects and fatalities. As a result of the perception that herbal medicinal products have low risk, consumers usually disregard any association between their use and any adverse reactions hence leading to underreporting of adverse reactions. This is particularly common in developing countries and has led to a paucity of scientific data regarding the toxicity and interactions of locally used traditional herbal medicine. Other factors like general lack of compositional and toxicological information of herbs and poor quality of adverse reaction case reports present hurdles which are highly underestimated by the population in the developing world. This review paper addresses these toxicological challenges and calls for natural health product regulations as well as for protocols and guidance documents on safety and toxicity testing of herbal medicinal products.
Dixon once told me that GPs do not any longer read scientific papers. I think, however, that he should start doing so before the next time he misinform the public and endangers the health of vulnerable people.