Dutch neurologists recently described the case of a 63-year-old female patient presented at their outpatient clinic with a five-week history of severe postural headache, tinnitus and nausea. The onset of these symptoms was concurrent with chiropractic manipulation of the cervical spine which she had tried because of cervical pain.
Cranial MRI showed findings characteristic for intracranial hypotension syndrome. Cervical MRI revealed a large posterior dural tear at the level of C1-2. Following unsuccessful conservative therapy, the patient underwent a lumbar epidural blood patch after which she recovered rapidly.
The authors conclude that manipulation of the cervical spine can cause a dural tear and subsequently an intracranial hypotension syndrome. Postural headaches directly after spinal manipulation should therefore be a reason to suspect this complication. If conservative management fails, an epidural blood patch may be performed.
Quite obviously, this is sound advice that can save lives. The trouble, however, is that the chiropractic profession is, by and large, still in denial. A recent systematic review by a chiropractor included eight cases of intracranial hypotension (IH) and concluded that case reports on IH and spinal manipulative therapy (SMT) have very limited clinical details and therefore cannot exclude other theories or plausible alternatives to explain the IH. To date, the evidence that cervical SMT is not a cause of IH is inconclusive. Further research is required before making any conclusions that cervical SMT is a cause of IH. Chiropractors and other health practitioners should be vigilant in recording established risk factors for IH in all cases. It is possible that the published cases of cervical SMT and IH may have missed important confounding risk factors (e.g. a new headache, or minor neck trauma in young or middle-aged adults).
Instead of distracting us from the fact that chiropractic can lead to serious adverse events, chiropractors would be well-advised to face the music, admit that their treatments are not risk-free and conduct rigorous research with a view of minimizing the harm.
The purpose of this paper by Canadian chiropractors was to expand practitioners’ knowledge on areas of liability when treating low back pain patients. Six cases where chiropractors in Canada were sued for allegedly causing or aggravating lumbar disc herniation after spinal manipulative therapy were retrieved using the CANLII database.
The patients were 4 men and 2 women with an average age of 37 years. Trial courts’ decisions were rendered between 2000 and 2011. The following conclusions from Canadian courts were noted:
- informed consent is an on-going process that cannot be entirely delegated to office personnel;
- when the patient’s history reveals risk factors for lumbar disc herniation the chiropractor has the duty to rule out disc pathology as an aetiology for the symptoms presented by the patients before beginning anything but conservative palliative treatment;
- lumbar disc herniation may be triggered by spinal manipulative therapy on vertebral segments distant from the involved herniated disc such as the thoracic spine.
The fact that this article was published by chiropractors seems like a step into the right direction. Disc herniations after chiropractic have been reported regularly and since many years. It is not often that I hear chiropractors admit that their spinal manipulations carry serious risks.
And it is not often that chiropractors consider the issue of informed consent. One the one hand, one hardly can blame them for it: if they ever did take informed consent seriously and informed their patients fully about the evidence and risks of their treatments as well as those of other therapeutic options, they would probably be out of business for ever. One the other hand, chiropractors should not be allowed to continue excluding themselves from the generally accepted ethical standards of modern health care.
The most widely used definition of EVIDENCE-BASED MEDICINE (EBM) is probably this one: The judicious use of the best current available scientific research in making decisions about the care of patients. Evidence-based medicine (EBM) is intended to integrate clinical expertise with the research evidence and patient values.
David Sackett’s own definition is a little different: Evidence based medicine is the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients. The practice of evidence based medicine means integrating individual clinical expertise with the best available external clinical evidence from systematic research.
Even though the principles of EBM are now widely accepted, there are those who point out that EBM has its limitations. The major criticisms of EBM relate to five themes: reliance on empiricism, narrow definition of evidence, lack of evidence of efficacy, limited usefulness for individual patients, and threats to the autonomy of the doctor/patient relationship.
Advocates of alternative medicine have been particularly vocal in pointing out that EBM is not really applicable to their area. However, as their arguments were less than convincing, a new strategy for dealing with EBM seemed necessary. Some proponents of alternative medicine therefore are now trying to hoist EBM-advocates by their own petard.
In doing so they refer directly to the definitions of EBM and argue that EBM has to fulfil at least three criteria: 1) external best evidence, 2) clinical expertise and 3) patient values or preferences.
Using this argument, they thrive to demonstrate that almost everything in alternative medicine is evidence-based. Let me explain this with two deliberately extreme examples.
CRYSTAL THERAPY FOR CURING CANCER
There is, of course, not a jot of evidence for this. But there may well be the opinion held by crystal therapist that some cancer patients respond to their treatment. Thus the ‘best’ available evidence is clearly positive, they argue. Certainly the clinical expertise of these crystal therapists is positive. So, if a cancer patient wants crystal therapy, all three preconditions are fulfilled and CRYSTAL THERAPY IS ENTIRELY EVIDENCE-BASED.
CHIROPRACTIC FOR ASTHMA
Even the most optimistic chiropractor would find it hard to deny that the best evidence does not demonstrate the effectiveness of chiropractic for asthma. But never mind, the clinical expertise of the chiropractor may well be positive. If the patient has a preference for chiropractic, at least two of the three conditions are fulfilled. Therefore – on balance – chiropractic for asthma is [fairly] evidence-based.
The ‘HOISTING ON THE PETARD OF EBM’-method is thus a perfect technique for turning the principles of EBM upside down. Its application leads us straight back into the dark ages of medicine when anything was legitimate as long as some charlatan could convince his patients to endure his quackery and pay for it – if necessary with his life.
Do you think that chiropractic is effective for asthma? I don’t – in fact, I know it isn’t because, in 2009, I have published a systematic review of the available RCTs which showed quite clearly that the best evidence suggested chiropractic was ineffective for that condition.
But this is clearly not true, might some enthusiasts reply. What is more, they can even refer to a 2010 systematic review which indicates that chiropractic is effective; its conclusions speak a very clear language: …the eight retrieved studies indicated that chiropractic care showed improvements in subjective measures and, to a lesser degree objective measures… How on earth can this be?
I would not be surprised, if chiropractors claimed the discrepancy is due to the fact that Prof Ernst is biased. Others might point out that the more recent review includes more studies and thus ought to be more reliable. The newer review does, in fact, have about twice the number of studies than mine.
How come? Were plenty of new RCTs published during the 12 months that lay between the two publications? The answer is NO. But why then the discrepant conclusions?
The answer is much less puzzling than you might think. The ‘alchemists of alternative medicine’ regularly succeed in smuggling non-evidence into such reviews in order to beautify the overall picture and confirm their wishful thinking. The case of chiropractic for asthma does by no means stand alone, but it is a classic example of how we are being misled by charlatans.
Anyone who reads the full text of the two reviews mentioned above will find that they do, in fact, include exactly the same amount of RCTs. The reason why they arrive at different conclusions is simple: the enthusiasts’ review added NON-EVIDENCE to the existing RCTs. To be precise, the authors included one case series, one case study, one survey, two randomized controlled trials (RCTs), one randomized patient and observer blinded cross-over trial, one single blind cross study design, and one self-reported impairment questionnaire.
Now, there is nothing wrong with case reports, case series, or surveys – except THEY TELL US NOTHING ABOUT EFFECTIVENESS. I would bet my last shirt that the authors know all of that; yet they make fairly firm and positive conclusions about effectiveness. As the RCT-results collectively happen to be negative, they even pretend that case reports etc. outweigh the findings of RCTs.
And why do they do that? Because they are interested in the truth, or because they don’t mind using alchemy in order to mislead us? Your guess is as good as mine.
Systematic reviews are widely considered to be the most reliable type of evidence for judging the effectiveness of therapeutic interventions. Such reviews should be focused on a well-defined research question and identify, critically appraise and synthesize the totality of the high quality research evidence relevant to that question. Often it is possible to pool the data from individual studies and thus create a new numerical result of the existing evidence; in this case, we speak of a meta-analysis, a sub-category of systematic reviews.
One strength of systematic review is that they minimise selection and random biases by considering at the totality of the evidence of a pre-defined nature and quality. A crucial precondition, however, is that the quality of the primary studies is critically assessed. If this is done well, the researchers will usually be able to determine how robust any given result is, and whether high quality trials generate similar findings as those of lower quality. If there is a discrepancy between findings from rigorous and flimsy studies, it is obviously advisable to trust the former and discard the latter.
And this is where systematic reviews of alternative treatments can run into difficulties. For any given research question in this area we usually have a paucity of primary studies. Equally important is the fact that many of the available trials tend to be of low quality. Consequently, there often is a lack of high quality studies, and this makes it all the more important to include a robust critical evaluation of the primary data. Not doing so would render the overall result of the review less than reliable – in fact, such a paper would not qualify as a systematic review at all; it would be a pseudo-systematic review, i.e. a review which pretends to be systematic but, in fact, is not. Such papers are a menace in that they can seriously mislead us, particularly if we are not familiar with the essential requirements for a reliable review.
This is precisely where some promoters of bogus treatments seem to see their opportunity of making their unproven therapy look as though it was evidence-based. Pseudo-systematic reviews can be manipulated to yield a desired outcome. In my last post, I have shown that this can be done by including treatments which are effective so that an ineffective therapy appears effective (“chiropractic is so much more than just spinal manipulation”). An even simpler method is to exclude some of the studies that contradict one’s belief from the review. Obviously, the review would then not comprise the totality of the available evidence. But, unless the reader bothers to do a considerable amount of research, he/she would be highly unlikely to notice. All one needs to do is to smuggle the paper past the peer-review process – hardly a difficult task, given the plethora of alternative medicine journals that bend over backwards to publish any rubbish as long as it promotes alternative medicine.
Alternatively (or in addition) one can save oneself a lot of work and omit the process of critically evaluating the primary studies. This method is increasingly popular in alternative medicine. It is a fool-proof method of generating a false-positive overall result. As poor quality trials have a tendency to deliver false-positive results, it is obvious that a predominance of flimsy studies must create a false-positive result.
A particularly notorious example of a pseudo-systematic review that used this as well as most of the other tricks for misleading the reader is the famous ‘systematic’ review by Bronfort et al. It was commissioned by the UK GENERAL CHIROPRACTIC COUNCIL after the chiropractic profession got into trouble and was keen to defend those bogus treatments disclosed by Simon Singh. Bronfort and his colleagues thus swiftly published (of course, in a chiro-journal) an all-encompassing review attempting to show that, at least for some conditions, chiropractic was effective. Its lengthy conclusions seemed encouraging: Spinal manipulation/mobilization is effective in adults for: acute, subacute, and chronic low back pain; migraine and cervicogenic headache; cervicogenic dizziness; manipulation/mobilization is effective for several extremity joint conditions; and thoracic manipulation/mobilization is effective for acute/subacute neck pain. The evidence is inconclusive for cervical manipulation/mobilization alone for neck pain of any duration, and for manipulation/mobilization for mid back pain, sciatica, tension-type headache, coccydynia, temporomandibular joint disorders, fibromyalgia, premenstrual syndrome, and pneumonia in older adults. Spinal manipulation is not effective for asthma and dysmenorrhea when compared to sham manipulation, or for Stage 1 hypertension when added to an antihypertensive diet. In children, the evidence is inconclusive regarding the effectiveness for otitis media and enuresis, and it is not effective for infantile colic and asthma when compared to sham manipulation. Massage is effective in adults for chronic low back pain and chronic neck pain. The evidence is inconclusive for knee osteoarthritis, fibromyalgia, myofascial pain syndrome, migraine headache, and premenstrual syndrome. In children, the evidence is inconclusive for asthma and infantile colic.
Chiropractors across the world cite this paper as evidence that chiropractic has at least some evidence base. What they omit to tell us (perhaps because they do not appreciate it themselves) is the fact that Bronfort et al
- failed to formulate a focussed research question,
- invented his own categories of inconclusive findings,
- included all sorts of studies which had nothing to do with chiropractic,
- and did not to make an assessment of the quality of the included primary studies they included in their review.
If, for a certain condition, three trials were included, for instance, two of which were positive but of poor quality and one was negative but of good quality, the authors would conclude that, overall, there is sound evidence.
Bronfort himself is, of course, more than likely to know all that (he has learnt his trade with an excellent Dutch research team and published several high quality reviews) – but his readers mostly don’t. And for chiropractors, this ‘systematic’ review is now considered to be the most reliable evidence in their field.
Imagine a type of therapeutic intervention that has been shown to be useless. Let’s take surgery, for instance. Imagine that research had established with a high degree of certainty that surgical operations are ineffective. Imagine further that surgeons, once they can no longer hide this evidence, argue that good surgeons do much more than just operate: surgeons wash their hands which effectively reduces the risk of infections, they prescribe medications, they recommend rehabilitative and preventative treatments, etc. All of these measures are demonstratively effective in their own right, never mind the actual surgery. Therefore, surgeons could argue that the things surgeons do are demonstrably effective and helpful, even though surgery itself would be useless in this imagined scenario.
I am, of course, not for a minute claiming that surgery is rubbish, but I have used this rather extreme example to expose the flawed argument that is often used in alternative medicine for white-washing bogus treatments. The notion is that, because a particular alternative health care profession employs not just one but multiple forms of treatments, it should not be judged by the effectiveness of its signature-therapy, particularly if it happens to be ineffective.
This type of logic seems nowhere more prevalent than in the realm of chiropractic. Its founding father, D.D. Palmer, dreamt up the bizarre notion that all human disease is caused by ‘subluxations’ which require spinal manipulation for returning the ill person to good health. Consequently, most chiropractors see spinal manipulation as a panacea and use this type of treatment for almost 100% of their patients. In other words, spinal manipulation is as much the hallmark-therapy for chiropractic as surgery is for surgeons.
When someone points out that, for this or that condition, spinal manipulation is not of proven effectiveness or even of proven ineffectiveness, chiropractors have in recent years taken to answering as outlined above; they might say: WE DO ALL SORTS OF OTHER THINGS TOO, YOU KNOW. FOR INSTANCE, WE EMPLOY OTHER MANUAL TECHNIQUES, GIVE LIFE-STYLE ADVICE AND USE NO END OF PHYSIOTHERAPEUTIC INTERVENTIONS. YOU CANNOT SAY THAT THESE APPROACHES ARE BOGUS. THEREFORE CHIROPRACTIC IS FAR FROM USELESS.
To increase the chances of convincing us with this notion, they have, in recent months, produced dozens of ‘systematic reviews’ which allegedly prove their point. Here are some of the conclusions from these articles which usually get published in chiro-journals:
The majority of the included trials appeared to indicate that the parents of infants receiving manipulative therapies reported fewer hours crying per day than parents whose infants did not, based on contemporaneous crying diaries, and this difference was statistically significant.
This study found a level of B or fair evidence for manual manipulative therapy of the shoulder, shoulder girdle, and/or the FKC combined with multimodal or exercise therapy for rotator cuff injuries/disorders, disease, or dysfunction.
Personally, I find this kind of ‘logic’ irritatingly illogical. If we accept it as valid, the boundaries between sense and nonsense disappear, and our tools of differentiating between quackery and ethical health care become blunt.
The next step could then even be to claim that a homeopathic hospital must be a good thing because some of its clinicians occasionally also prescribe non-homeopathic treatments.
Whenever a new trial of an alternative intervention emerges which fails to confirm the wishful thinking of the proponents of that therapy, the world of alternative medicine is in turmoil. What can be done about yet another piece of unfavourable evidence? The easiest solution would be to ignore it, of course – and this is precisely what is often tried. But this tactic usually proves to be unsatisfactory; it does not neutralise the new evidence, and each time someone brings it up, one has to stick one’s head back into the sand. Rather than denying its existence, it would be preferable to have a tool which invalidates the study in question once and for all.
The ‘fatal flaw’ solution is simpler than anticipated! Alternative treatments are ‘very special’, and this notion must be emphasised, blown up beyond all proportions and used cleverly to discredit studies with unfavourable outcomes: the trick is simply to claim that studies with unfavourable results have a ‘fatal flaw’ in the way the alternative treatment was applied. As only the experts in the ‘very special’ treatment in question are able to judge the adequacy of their therapy, nobody is allowed to doubt their verdict.
Take acupuncture, for instance; it is an ancient ‘art’ which only the very best will ever master – at least that is what we are being told. So, all the proponents need to do in order to invalidate a trial, is read the methods section of the paper in full detail and state ‘ex cathedra’ that the way acupuncture was done in this particular study is completely ridiculous. The wrong points were stimulated, or the right points were stimulated but not long enough [or too long], or the needling was too deep [or too shallow], or the type of stimulus employed was not as recommended by TCM experts, or the contra-indications were not observed etc. etc.
As nobody can tell a correct acupuncture from an incorrect one, this ‘fatal flaw’ method is fairly fool-proof. It is also ever so simple: acupuncture-fans do not necessarily study hard to find the ‘fatal flaw’, they only have to look at the result of a study – if it was favourable, the treatment was obviously done perfectly by highly experienced experts; if it was unfavourable, the therapists clearly must have been morons who picked up their acupuncture skills in a single weekend course. The reasons for this judgement can always be found or, if all else fails, invented.
And the end-result of the ‘fatal flaw’ method is most satisfactory; what is more, it can be applied to all alternative therapies – homeopathy, herbal medicine, reflexology, Reiki healing, colonic irrigation…the method works for all of them! What is even more, the ‘fatal flaw’ method is adaptable to other aspects of scientific investigations such that it fits every conceivable circumstance.
An article documenting the ‘fatal flaw’ has to be published, of course – but this is no problem! There are dozens of dodgy alternative medicine journals which are only too keen to print even the most far-fetched nonsense as long as it promotes alternative medicine in some way. Once this paper is published, the proponents of the therapy in question have a comfortable default position to rely on each time someone cites the unfavourable study: “WHAT NOT THAT STUDY AGAIN! THE TREATMENT HAS BEEN SHOWN TO BE ALL WRONG. NOBODY CAN EXPECT GOOD RESULTS FROM A THERAPY THAT WAS NOT CORRECTLY ADMINISTERED. IF YOU DON’T HAVE BETTER STUDIES TO SUPPORT YOUR ARGUMENTS, YOU BETTER SHUT UP.”
There might, in fact, be better studies – but chances are that the ‘other side’ has already documented a ‘fatal flaw’ in them too.
It is usually BIG PHARMA who stands accused of being less than honest with the evidence, particularly when it runs against commercial interests; and the allegations prove to be correct with depressing regularity. In alternative medicine, commercial interests exist too, but there is usually much less money at stake. So, a common assumption is that conflicts of interest are less relevant in alternative medicine. Like so many assumptions in this area, this notion is clearly and demonstrably erroneous.
The sums of money are definitely smaller, but non-commercial conflicts of interest are potentially more important than the commercial ones. I am thinking of the quasi-religious beliefs that are so very prevalent in alternative medicine. Belief can move mountains, they say – it can surely delude people and make them do the most extraordinary things. Belief can transform advocates of alternative medicine into ‘ALCHEMISTS OF ALTERNATIVE EVIDENCE’ who turn negative/unfavourable into positive/favourable evidence.
The alchemists’ ‘tricks of the trade’ are often the same as used by BIG PHARMA; they include:
- drawing conclusions which are not supported by the data
- designing studies such that they will inevitably generate a favourable result
- cherry-picking the evidence
- hiding unfavourable findings
- publishing favourable results multiple times
- submitting data-sets to multiple statistical tests until a positive result emerges
- defaming scientists who publish unfavourable findings
- bribing experts
- prettify data
- falsifying data
As I said, these methods, albeit despicable, are well-known to pseudoscientists in all fields of inquiry. To assume that they are unknown in alternative medicine is naïve and unrealistic, as many of my previous posts confirm.
In addition to these ubiquitous ‘standard’ methods of scientific misconduct and fraud, there are a few techniques which are more or less unique to and typical for the alchemists of alternative medicine. In the following parts of this series of articles, I will try to explain these methods in more detail.
Steve Scrutton is a UK homeopath on a mission; he seems to want to promote homeopathy at all cost – so much so that he recently ran into trouble with the ASA for breaching CAP Code (Edition 12) rules 3.1 and 3.3 (Misleading advertising), 3.7 (Substantiation) and 12.1, 12.2 and 12.6 (Medicines, medical devices, health-related products and beauty products). Scrutton happens to be a Director of the ‘ALLIANCE OF REGISTERED HOMEOPATHS’ (ARH) which represents nearly 700 homeopaths in the UK. On one of his websites, he promotes homeopathy as a treatment and prevention for measles:
Many homeopaths feel that it is better for children, who are otherwise healthy, to contract measles naturally. Homeopathy is less concerned with doing this as it has remedies to treat measles, especially if it persists, or become severe.Other homeopaths will use the measles nosode, Morbillinum, for prevention.Homeopaths have been treating measles for over 200 years with success.
The main remedies used for the condition, according to Scrutton, are the following: Aconite, Belladonna, Gelsemium, Euphrasia, Bryonia, Pulsatilla, Kali Bich, Sulphur, Apis Mel or Arsenicum – depending on the exact set of presenting symptoms.
At the very end of this revealing post, Scrutton makes the following statement: To my knowledge, there have been no RCTs conducted on either the prevention or treatment of Measles with Homeopathy. However, homeopaths have been treating Measles safely and effectively since the early 19th Century, and through many serious epidemics throughout the world.
Why would anyone write such dangerous nonsense, particularly in the position of a director of the ARH? There can, in my view be only one answer: he must be seriously deluded and bar any knowledge what sound medical evidence looks like. One of his articles seems to confirm this suspicion; in 2008, Scrutton wrote: What ‘scientific’ medicine does not like about homeopathy is not the lack of an evidence base – it is the ability to help people get well – and perhaps even more important, we can do it safely.
Intriguingly, the ARH has a code of ethics which states that members must not claim or imply, orally or in writing, to be able to cure any named disease and that they should be aware of the extent and limits of their clinical skills.
Could it be that a director of the ARH violates his own code of ethics?
I am sure, we have all heard it hundreds of times: THERE ARE IMPORTANT LINKS BETWEEN OUR DIET AND CERTAIN CANCERS. The evidence for this statement seems fairly compelling. Yet it also is complex and often confusing.
A recent review, for instance, suggested that fruits (particularly citrus) and vegetable consumption may be beneficial in the primary prevention of pancreatic cancer, the consumption of whole grains has been shown to reduce the risk and fortification of whole grains with folate may confer further protection. Red meat, cooked at high temperatures, should be avoided, and replaced with poultry or fish. Total fat should be reduced. The use of curcumin and other flavonoids should be encouraged in the diet. Another equally recent review, however, indicated that there is no conclusive evidence as an independent risk factor for isolated nutrients versus adoption of dietary patterns for cancer risk. Cancer colon risk derived from meat intake is influenced by both total intake and its frequency. The interaction of phenolic compounds on metabolic and signalling pathways seems to exert an inhibitory effect on cell proliferation and tumor metastasis and induces apoptosis in various types of cancer cells, including colon, lung, prostate, hepatocellular or breast cancer. A third recent review concluded that cruciferous vegetable intake protects against cancer of the colon, while a forth review suggested that the Mediterranean dietary pattern and diets composed largely of vegetables, fruit, fish, and soy are associated with a decreased risk of breast cancer. There was no evidence of an association between traditional dietary patterns and risk of breast cancer.
Not least based on these mixed messages from the scientific literature, an entire industry has developed selling uncounted alternative cancer-diets and dietary supplements to desperate patients and consumers. They promise much more than just cancer prevention, in fact, leave little doubt about the notion that cancer might be curable by diet. Here are just a few quotes from the thousands of websites promoting alternative cancer diets:
- The Ketogenic Diet is believed capable of starving cancer cells to death, and thus capable of restricting tumour development.
- a more alkaline body makes it difficult for tumors to grow.
- Budwig diet: This diet was developed by Dr. Johanna Budwig who was nominated for the noble Prize sixth times. The diet is intended as a preventative as well as an alternative cancer treatment.
- the Gerson Therapy naturally reactivates your body’s magnificent ability to heal itself – with no damaging side effects. This a powerful, natural treatment boosts the body’s own immune system to heal cancer, arthritis, heart disease, allergies, and many other degenerative diseases. Dr. Max Gerson developed the Gerson Therapy in the 1930s, initially as a treatment for his own debilitating migraines, and eventually as a treatment for degenerative diseases such as skin tuberculosis, diabetes and, most famously, cancer.
- the concept of macrobiotics is much more than an alternative diet for cancer, or any other illness, but rather the ancient Chinese belief that all life, indeed the whole universe, is a balance of two opposing forces Yin and Yang.
Confused? Yes, I do worry how many cancer patients listen to these claims and pin their hopes on one of these diets. But what exactly does the evidence tell us about them?
A German team of researchers evaluated the following alternative cancer-diets: raw vegetables and fruits, alkaline diet, macrobiotics, Gerson’s regime, Budwig’s and low carbohydrate or ketogenic diet. Their extensive searches of the published literature failed to find clinical evidence supporting any of the diets. Furthermore, case reports and pre-clinical data pointed to the potential harm of some of these diets. The authors concluded that considering the lack of evidence of benefits from cancer diets and potential harm by malnutrition, oncologists should engage more in counselling cancer patients on such diets.
In other words, alternative cancer diets – and I mean not just the ones mentioned above, but all of them – are not supported by good evidence for efficacy as a treatment or prevention of any type of cancer. In addition, they might also cause harm.
What follows is obvious: cancer patients should take sound nutritional advice and adopt a healthy general life-style. But they should run a mile as soon as anyone suggests an alternative dietary cure for their disease.