MD, PhD, FMedSci, FSB, FRCP, FRCPEd

Monthly Archives: June 2013

Sorry, but I am fighting a spell of depression today.

Why? I came across this website which lists the 10 top blogs on alternative medicine. To be precise, here is what they say about their hit-list: this list includes the top 10 alternative medicine bloggers on Twitter, ranked by Klout score. Using Cision’s media database, we compiled the list based on Cision’s proprietary research, with results limited to bloggers who dedicate significant coverage to alternative medicine and therapies…

And here are the glorious top ten:

Andrew WeilDr. Andrew Weil’s Daily Health Tips

Joy McCarthyJoyous Health Blog

Johanna BjörkGoodlifer

Stacey ChillemiStay Healthy and Cure Your Conditions Naturally

Eric GreyDeepest Health

Kristi ShmyrPrana Holistic Blog

Cathy WongAlternative Medicine Blog

Renee CanadaHartford Healthy Living Examiner

Dee BraunNatural Holistic Health Blog

Geo EspinosaDr. Geo’s Natural Health Blog

All of these sites are promotional and lack even the slightest hint of critical evaluation. All of them sell or advertise products and are thus out to make money. All of them are full of quackery, in my view. Some of the most popular bloggers are world-famous quacks!

What about impartial information for the public? What about critical review of the evidence? What about a degree of balance? What about guiding consumers to make responsible, evidence-based decisions? What about preventing harm? What about using scarce resources wisely?

I don’t see any of this on any of the sites.

You see, now I have depressed you too!

Quick, buy some herbal, natural, holistic and integrative anti-depressant! As it happens, I have some for sale….

Some people will probably think that I am obsessed with writing about the risk of chiropractic. True, I have published quite a bit on this subject, both in the peer-reviewed literature as well as on this blog – but not because I am obsessed; on this blog, I will re-visit the topic every time a relevant new piece of evidence becomes available because it is indisputably such an important subject. Writing about it might prevent harm.

So far, we know for sure that mild to moderate as well as serious complications, including deaths, do occur after chiropractic spinal manipulations, particularly those of the upper spine.  What we cannot say with absolute certainty is whether they are caused by the treatment or whether they happened coincidentally. Our knowledge in this area relies mostly on case-reports and surveys which, by their very nature, do not allow causal inferences. Therefore chiropractors have, in the past, been able to argue that a causal link remains unproven.

A brand-new blinded parallel group RCT might fill this gap in our knowledge and might reject or establish the notion of causality once and for all. The authors’ objective was to establish the frequency and severity of adverse effects from short term usual chiropractic treatment of the spine when compared to a sham treatment group. They thus conducted the first ever RCT  with the specific aim to examine the occurrence of adverse events resulting from chiropractic treatment. It was conducted across 12 chiropractic clinics in Perth, Western Australia. The participants comprised 183 adults, aged 20-85, with spinal pain. Ninety two participants received individualized care consistent with the chiropractors’ usual treatment approach; 91 participants received a sham intervention. Each participant received two treatment sessions.

Completed adverse questionnaires were returned by 94.5% of the participants after the first appointment and 91.3% after the second appointment. Thirty three per cent of the sham group and 42% of the usual care group reported at least one adverse event. Common adverse events were increased pain (sham 29%; usual care 36%), muscle stiffness (sham 29%; usual care 37%), headache (sham 17%; usual care 9%). The relative risk was not significant for either adverse event occurrence (RR = 1.24 95% CI 0.85 to 1.81); occurrence of severe adverse events (RR = 1.9; 95% CI 0.98 to 3.99); adverse event onset (RR = 0.16; 95% CI 0.02 to 1.34); or adverse event duration (RR = 1.13; 95% CI 0.59 to 2.18). No serious adverse events were reported.

The authors concluded that a substantial proportion of adverse events following chiropractic treatment may result from natural history variation and non-specific effects.

If we want to assess causality of effects, we have no better option than to conduct an RCT. It is the study design that can give us certainty, or at least near certainty – that is, if the RCT is rigorous and well-made. So, does this study reject or confirm causality? The disappointing truth is that it does neither.

Adverse events were clearly more frequent with real as compared to sham-treatment. Yet the difference failed to be statistically significant. Why? There are at least two possibilities: either there was no true difference and the numerically different percentages are a mere fluke; or there was a true difference but the sample size was too small to prove it.

My money is on the second option. The number of patients was, in my view, way too small for demonstrating differences in frequencies of adverse effects. This applies to the adverse effects noted, but also, and more importantly, to the ones not noted.

The authors state that no serious adverse effects were observed. With less that 200 patients participating, it would have been most amazing to see a case of arterial dissection or stroke. From all we currently know, such events are quite rare and occur perhaps in one of 10 000 patients or even less often. This means that one would require a trial of several hundred thousand patients to note just a few of such events, and an RCT with several million patients to see a difference between real and sham treatment. It seems likely that such an undertaking will never be affordable.

So, what does this new study tell us? In my view, it is strong evidence to suggest a causal kink between chiropractic treatment and mild to moderate adverse effects. I dose not prove it, but merely suggests it – yet I am fairly sure that chiropractors, once again, will not agree with me.

Postoperative ileus (POI), the phenomenon that after an operation the intestines tend to be inactive for a few days, can cause intense pain and thus contributes significantly to human suffering. It also prolongs hospital stay and increases the risks of post-operative complications. There is no known effective treatment for POI.

In China, POI is often treated with acupuncture, and due to this fact acupuncture became known in the West: James Reston, a journalist who accompanied Nixon on his first trip to China, had to have an appendectomy in a Beijing hospital, he subsequently suffered from POI, was treated with acupuncture and moxibustion, experienced symptom-relief, and subsequently wrote about it in the New York Times. This was the beginning of the present acupuncture-boom.

Since then, thousands of acupuncture trials have been published but, intriguingly, very few have tested the effectiveness of acupuncture for POI. Now researchers from the Sloan Kettering Cancer Center in New York have conducted a randomized, sham-controlled trial to test whether acupuncture reduces POI more effectively than sham acupuncture.

Ninety colon cancer patients undergoing elective colectomy were randomized to receive 30 min of true or sham acupuncture twice daily during their first three postoperative days. GI-3 (the later of the following two events: time that the patient first tolerated solid food, AND time that the patient first passed flatus OR a bowel movement) and GI-2 (the later of the following two events: time patient first tolerated solid food AND time patient first passed a bowel movement) were determined. Pain, nausea, vomiting, and use of pain medications were evaluated daily for the first three postoperative days. Eighty-one patients received the allocated intervention: 39 the true acupuncture and 42 the sham acupuncture. The mean time to GI-3 was 149 hours and 146 hours for the acupuncture group and the sham acupuncture group. No significant differences were found between groups for secondary endpoints.

The authors’ conclusion was clear: True acupuncture as provided in this study did not reduce POI more significantly than sham acupuncture.

So, did a mere misunderstanding start the present acupuncture boom? POI inevitably normalises with time. Did the journalist just imagine that acupuncture helped, while nature cured the condition? It would seem so, according to this study. But perhaps things are not just black or white. Almost at the same time as the New York trial, another study was emerged.

Researchers from Hong Kong conducted an RCT with 165 patients undergoing elective laparoscopic surgery for colonic and upper rectal cancer. Patients were assigned randomly to receive electroacupuncture (n = 55) or sham acupuncture (n = 55), once daily from postoperative days 1-4, or no acupuncture (n = 55). The primary outcome was time to defecation. Secondary outcomes included postoperative analgesic requirement, time to ambulation, and length of hospital stay. The results showed that patients who received electroacupuncture had a shorter time to defecation than patients who received no acupuncture (85.9 ± 36.1 vs 122.1 ± 53.5 h) and length of hospital stay (6.5 ± 2.2 vs 8.5 ± 4.8 days). Patients who received electroacupuncture also had a shorter time to defecation than patients who received sham acupuncture (85.9 ± 36.1 vs 107.5 ± 46.2 h). Electroacupuncture was more effective than no or sham acupuncture in reducing postoperative analgesic requirement and time to ambulation.

The Chinese researchers’ conclusion is equally clear: electroacupuncture reduced the duration of postoperative ileus, time to ambulation, and postoperative analgesic requirement, compared with no or sham acupuncture, after laparoscopic surgery for colorectal cancer.

The only other trial I know in this area failed to show that acupuncture shortens POI. What should we make of these data? A systematic review would be nice, of course, but, to the best of my knowledge, none is currently available.

Is this a question of everyone being able to pick and chose the evidence they like? Is it a question of who we trust, the researchers in New York or those in China? Is it a question of where the treatment was done authentically? Is it a question of critically analysing which study had the higher risks of bias? Or is it a question of simply saying that two negative studies are more than one positive trial?

Confused? Me too, a little!

Whatever answers we chose, several things seems fairly certain to me. It would be wrong to say that there is good evidence for acupuncture as a treatment of POI. And the acupuncture-boom that ensued after Reston’s article was to a very large degree built on a simple misunderstanding: POI is a condition that resolves literally into thin air whether we treat it or not.

On this blog, we have repeatedly discussed the serious adverse effects of Spinal Manipulative Therapies (SMT) as frequently administered by chiropractors, osteopaths and physiotherapists. These events mostly relate to vascular accidents involving vertebral or carotid arterial dissections after SMT of the upper spine. Lower down, the spine is anatomically far less vulnerable which, however, does not mean that injuries in this region after SMT are impossible. They have been reported repeatedly but, to the best of my knowledge, there is no up-to-date review of such events – that is until recently.

Australian researchers have just filled this gap by publishing a systematic review aimed at systematically reviewing all reports of serious adverse events following lumbo-pelvic SMT. They conducted electronic searches in MEDLINE, EMBASE, CINAHL, and The Cochrane Library up to January 12, 2012. Article-selection was performed by two independent reviewers using predefined criteria. Cases were included involving individuals 18 years or older who experienced a serious adverse event following SMT applied to the lumbar spine or pelvis by any type of provider (chiropractic, medical, physical therapy, osteopathic, layperson). A serious adverse event was defined as an untoward occurrence that resulted in death or was life threatening, required hospital admission, or resulted in significant or permanent disability. Reports published in English, German, Dutch, and Swedish were included.

The searches identified a total of 2046 papers, and 41 articles reporting a total of 77 cases were included in the review. Important case details were frequently missing in these reports, such as descriptions of SMT technique, the pre-SMT presentation of the patient, the specific details of the adverse event, time from SMT to the adverse event, factors contributing to the adverse event, and clinical outcome.

The 77 adverse events consisted of cauda equina syndrome (29 cases); lumbar disk herniation (23 cases); fracture (7 cases); haematoma or haemorrhagic cyst (6 cases); and12 cases of neurologic or vascular compromise, soft tissue trauma, muscle abscess formation, disrupted fracture healing, and oesophageal rupture.

The authors’ conclusion was that this systematic review describes case details from published articles that describe serious adverse events that have been reported to occur following SMT of the lumbo-pelvic region. The anecdotal nature of these cases does not allow for causal inferences between SMT and the events identified in this review.

This review is timely and sound. Yet several factors need consideration:

1) The search strategy was thorough but it is unlikely that all relevant articles were retrieved because these papers are often well-hidden in obscure and not electronically listed journals.

2) It is laudable that the authors included languages other than English but it would have been preferable to impose no language restrictions at all.

3) Under-reporting of adverse events is a huge problem, and it is anyone’s guess how large it really is [we have shown that, in our research it was precisely 100%]

4) This means that the 77 cases, which seem like a minute number, could in reality be 770 or 7700 or 77000; nobody can tell.

Cauda equina (horse tail) syndrome was the most frequent and most serious adverse event reported. This condition is caused by nerve injury at the lower end of the spinal canal. Symptoms can include leg pain along the sciatic nerve, severe back pain, altered or loss of sensation over the area around the genitals, anus and inner thighs as well as urine retention or incontinence and faecal incontinence. The condition must be treated as an emergency and usually requires surgical decompression of the injured nerves.

Disk herniation, the second most frequent adverse event, is an interesting complication of SMT. Most therapists using SMT would probably claim (no, I have no reference for that speculation!) that they can effectively treat herniated disks with SMT. The evidence for this claim is, as far as I know, non-existent. In view of the fact that SMT can actually cause a disk to herniate, I wonder whether SMT should not be contra-indicated for this condition. I am sure there will be some discussion about this question following this post.

The authors make a strong point about the fact that case reports never allow causal inference. One can only agree with this notion. However, the precautionary principle in medicine also means that, if case reports provide reasonable suspicion that an intervention might led to adverse-effects, we need to be careful and should warn patients of this possibility. It also means that it is up to the users of SMT to demonstrate beyond reasonable doubt that SMT is safe.

A recent post of mine seems to have stimulated a lively discussion about the question IS THERE ANY GOOD EVIDENCE AT ALL FOR OSTEOPATHIC TREATMENTS? By and large, osteopaths commented that they are well aware that their signature interventions for their most frequently treated condition (back pain) lack evidential support and that more research is needed. At the same time, many osteopaths seemed to see little wrong in making unsubstantiated therapeutic claims. I thought this was remarkable and feel encouraged to write another post about a similar topic.

Most osteopaths treat children for a wide range of conditions and claim that their interventions are helpful. They believe that children are prone to structural problems which can be corrected by their interventions. Here is an example from just one of the numerous promotional websites on this topic:

STRUCTURAL  PROBLEMS, such as those affecting the proper mobility and function of the  body’s framework, can lead to a range of problems. These may include:

  • Postural – such as scoliosis
  • Respiratory  – such as asthma
  • Manifestations of brain  injury – such as cerebral palsy and spasticity
  • Developmental  – with delayed physical or intellectual progress, perhaps triggering learning  behaviour difficulties
  • Infections – such  as ear and throat infections or urinary disturbances, which may be recurrent.

OSTEOPATHY can assist in the prevention of health problems, helping children to make a smooth  transition into normal, healthy adult life.

As children cannot give informed consent, this is even more tricky than treating adults with therapies of questionable value. It is therefore important, I think, to ask whether osteopathic treatments of children is based on evidence or just on wishful thinking or the need to maximise income. As it happens, my team just published an article about these issues in one of the highest-ranking paediatrics journal.

The objective of our systematic review was to critically evaluate the effectiveness of osteopathic manipulative treatment (OMT) as a treatment of paediatric conditions. Eleven databases were searched from their respective inceptions to November 2012. Only randomized clinical trials (RCTs) were included, if they tested OMT against any type of control intervention in paediatric patients. The quality of all included RCTs was assessed using the Cochrane criteria.

Seventeen trials met our inclusion criteria. Only 5 RCTs were of high methodological quality. Of those, 1 favoured OMT, whereas 4 revealed no effect compared with various control interventions. Replications by independent researchers were available for two conditions only, and both failed to confirm the findings of the previous studies. Seven RCTs suggested that OMT leads to a significantly greater reduction in the symptoms of asthma, congenital nasolacrimal duct obstruction, daily weight gain and length of hospital stay, dysfunctional voiding, infantile colic, otitis media, or postural asymmetry compared with various control interventions. Seven RCTs indicated that OMT had no effect on the symptoms of asthma, cerebral palsy, idiopathic scoliosis, obstructive apnoea, otitis media, or temporo-mandibular disorders compared with various control interventions. Three RCTs did not report between-group comparisons. The majority of the included RCTs did not report the incidence rates of adverse-effects.

Our conclusion is likely to again dissatisfy many osteopaths: The evidence of the effectiveness of OMT for paediatric conditions remains unproven due to the paucity and low methodological quality of the primary studies.

So, what does this tell us? I am sure osteopaths will disagree, but I think it shows that for no paediatric condition do we have sufficient evidence to show that OMT is effective. The existing RCTs are mostly of low quality. There is a lack of independent replication of the few studies that suggested a positive outcome. And to make matters even worse, osteopaths seem to be violating the most basic rule of medical research by not reporting adverse-effects in their clinical trials.

I rest my case – at least for the moment.

A new condition, the Knighthood Starvation Syndrome (KSS), might soon be included in our systems of disease classification. Sporadic cases have been noted as far back as the 1950s, but recent decades have seen an alarming proliferation of incidents. The epidemiology of the KSS is most peculiar: it is endemic in the British Isles, particularly in large centres and seems to affect almost exclusively alpha males in their 60ies who have climbed up to dizzy heights on the career ladder and who think of themselves very highly.

The KSS tends to remain unrecognised for many years; early signs of dormant KSS include name dropping, pomposity, and a general alignment with the views of the establishment. Later stages are characterised by a sudden and often surprising change of opinion on several professional matters, an abnormal need for political correctness, an insatiable hunger for favourable mentions in the national press, a phobia related to rocking boats or blowing whistles, an urge to get involved in charitable work and/or high-profile committees of any type, and an increasing ruthlessness in pursuing ones personal goals under the guise of a professional purpose. Some of the features of the KSS are reminiscent of a classical degenerative disease, say experts who have studied the syndrome in much detail.

Opinions are divided as to the root causes of the KSS. Some psychiatrists claim it is due to early childhood mal-adaptation or bad potty-training, while sexologist are convinced that it caused by a chronically unfulfilled sex-life, and psychologists tend to believe it is a delayed mid-life crisis that was not allowed to blossom in a timely fashion. Endocrinologists have identifies various abnormalities regarding the levels of stress and sex hormones, nutritionists are discussing a lack of vitamin D in combination with an excess of red meat and fast food, and ENT surgeons speculate that it is caused by the absence of tonsillectomy during adolescence.

Unsurprisingly, alternative practitioners have developed their own theories most of which are, however, frowned upon by mainstream medics. Chiropractors view the KSS as the result of subluxation at the atlas level and advocate spinal adjustments followed by life-long maintenance therapy. TCM-practitioners are suggesting that a blocked kidney-chi has led to a pathological dominance of yin-energy, a minor aberration which could easily be corrected by acupuncture along the appropriate meridian. Bach Flower enthusiasts speak of vibrations being out of tune and recommend an intensive cure with Rescue Remedy. And finally, homeopaths see the KSS as the final poof of their theory of miasma where the bad air of the executive floor and caused serious damage which can only be neutralised by an in-depth homeopathic history and prolonged, individualised treatment.

Despite these and other attempts of altering the natural history of the syndrome, it tends to progress gradually in predisposed individuals, and symptoms are likely to worsen significantly over time, often to the point that the poor victim becomes a public menace. So far, the only known, evidence-based remedy is rather heroic and sadly not often available: the award of a knighthood. This intervention usually leads to a swift and uneventful recovery. In some tragic cases, however, the KSS subsequently degenerates into the HoLS-Syndrome, the even more vicious House of Lords Starvation Syndrome.

I have mentioned it before, I know, but it seems important, so please bear with me as I revisit the subject: there is no other area of health care that is more plagued by surveys than alternative medicine. They are usually conducted on a small convenience sample of consumers and try to tell us that many of them use and like alternative medicine (or a specific alternative treatment). And why is this important? Because this information is subsequently employed to convince us, politicians, journalists, heirs to the throne etc. that thousands of consumers cannot be wrong and that alternative medicine must therefore be a good thing.
Sceptics know, of course, that this argumentum ad populum is a classical fallacy. Recently, we published an article which provides fairly hard evidence to substantiate this fact.

The main aim of our systematic review was to estimate the prevalence of use of alternative medicine (AM) in the UK. Five databases were searched for peer-reviewed surveys published between 1 January 2000 and 7 October 2011. In addition, relevant book chapters and files from our own departmental records were searched by hand. Eighty-nine surveys were included, with a total of 97,222 participants. Surely, fact that this large amount of UK surveys had emerged in only about one decade, speaks for itself.

Most studies turned out to be of poor methodological quality. Across all surveys, the average one-year prevalence of AM-use was 41.1%, and the average lifetime prevalence was 51.8%. However, many of these investigations were flimsy. According to methodologically sound surveys, the equivalent rates were 26.3% and 44%, respectively. In surveys with response rates >70%, the average one-year prevalence was nearly threefold lower than in surveys with response rates below 50%. Herbal medicine was the most popular CAM, followed by homeopathy, aromatherapy, massage and reflexology.

To the best of my knowledge, this is the first time that four crucial points about such surveys have been clearly documented:

1) The amount of surveys in AM is staggering.

2) They contribute very little worthwhile knowledge and mostly seem to be exercises in AM-promotion.

3) Their methodological quality is usually low.

4) The poor quality surveys systematically over-estimate the prevalence of AM-use.

I think it is time that AM investigators focus on real research answering important questions which advance out knowledge, that AM-journal editors stop publishing meaningless nonsense, and that decision-makers understand the difference between promotion dressed up as science and real research.

 

 

Tai Chi, as we know it in the West, is said to promote the smooth flow of “energy” throughout the body by performing postures, slow meditative movements and controlled breathing. Tai Chi is also supposed to help increasing flexibility, suppleness, balance and coordination. According to enthusiasts, the smooth, gentle movements of Tai Chi aid relaxation and help to keep the mind calm and focused.

Tai Chi has become popular in Western countries and is being considered for a surprisingly wide range of conditions. The patient/consumer is taught to perform postures, slow meditative movements and controlled breathing. The concepts underlying Tai Chi are strange, but that does not necessarily mean that the treatment is not effective for certain illnesses or symptoms.

There has been a surprising amount of research in this area, and some studies have generated encouraging results. A recent study which is unfortunately not available electronically ( Wu, WF; Muheremu, A; Chen, CH; Liu, WG; Sun, L. Effectiveness of Tai Chi Practice for Non-Specific Chronic Low Back Pain on Retired Athletes: A Randomized Controlled Study. JOURNAL OF MUSCULOSKELETAL PAIN 2013, 21:1, p.37-45) tested the effectiveness of Tai Chi for chronic back pain. Specifically, the researchers wanted to determine whether regular Tai Chi practice is superior to other means of sports rehabilitation in relieving non-specific chronic low back pain [LBP] in a younger population. They randomized 320 former athletes suffering from chronic LBP into a treatment [tai chi practice] and several control groups [regular sessions with swimming, backward walking or jogging, or no such interventions]. At the beginning, middle, and end of a six-month intervention, patients from all groups completed questionnaires assessing the intensity of LBP; in addition, a physical examination was conducted.

After 3 and 6 months, no statistically significant difference in the intensity of LBP was demonstrated between the Tai Chi and swimming. However, significant differences were demonstrated between the Tai Chi and backward walking, jogging, and no exercise groups.

The authors’ concluded that “Tai chi has better efficacy than certain other sports on the treatment of non-specific chronic LBP.”

This is only the second RCT of Tai chi for back pain. The first such study consisted of 160 volunteers between ages 18 and 70 years with persistent nonspecific low back pain. The experimental group (n = 80) had 18 Tai Chi sessions over a 10-week period. The waitlist control group continued with their usual health care. Bothersomeness of symptoms was the primary outcome, and secondary outcomes included pain intensity and pain-related disability. Tai Chi reduced bothersomeness of back symptoms by 1.7 points on a 0-10 scale, reduced pain intensity by 1.3 points on a 0-10 scale, and improved self-report disability by 2.6 points on the 0-24 Roland-Morris Disability Questionnaire scale. The authors of this RCT concluded that a 10-week Tai Chi program improved pain and disability outcomes and can be considered a safe and effective intervention for those experiencing long-term low back pain symptoms.

My own team have conducted their fair share of Tai Chi research. Specifically,we have published several systematic reviews of Tai Chi as an adjunctive or supportive treatment of various conditions, and the conclusions (in italics) have been mixed.

DIABETES: The existing evidence does not suggest that tai chi is an effective therapy for type 2 diabetes.

HYPERTENSION: The evidence for tai chi in reducing blood pressure in the elderly individuals is limited.

BREAST CANCER: the existing trial evidence does not show convincingly that tai chi is effective for supportive breast cancer care.

IMPROVEMENT OF AEROBIC EXCERCISE CAPACITY: the existing evidence does not suggest that regular tai chi is an effective way of increasing aerobic capacity.

PARKINSON’S DISEASE: the evidence is insufficient to suggest tai chi is an effective intervention for Parkinson’s Disease.

OSTEOPOROSIS: The evidence for tai chi in the prevention or treatment of osteoporosis is not convincing.

OSTEOARTHRITIS: there is some encouraging evidence suggesting that tai chi may be effective for pain control in patients with knee OA.

RHEUMATOID ARTHRITIS: Collectively this evidence is not convincing enough to suggest that tai chi is an effective treatment for RA.

Finally, an overview over all systematic reviews of Tai Chi suggested that the only area where the evidence is convincing is the prevention of falls in the elderly.

I think, this indicates that we should not pin our hopes too high as to the therapeutic value of Tai Chi. In particular, for back pain, the evidence might be optimistically judged as encouraging, but it is by no means convincing; the effect size seems to be small and two studies are not enough to issue general recommendations. On the other hand, considering that there is so little to offer to back pain patients, I concede that this is an area that should be studied further. Meanwhile, one could argue that Tai Chi can be fun and is devoid of risks – so, why not give it a try?

Antioxidant vitamins include vitamin E, beta-carotene, and vitamin C. They are often recommended and widely used for preventing major cardiovascular outcomes. However, the effect of antioxidant vitamins on cardiovascular events remains unclear. There is plenty of evidence but the trouble is that it is not always of high quality and confusingly contradictory. Consequently, it is possible to cherry-pick the studies you prefer in order to come up with the answer you like. That this approach is counter-productive should be obvious to every reader of this blog. Only a rigorous systematic review can provide an answer that is as reliable as possible with the data available to date. Chinese researchers have just published such an assessment.

They searched PubMed, EmBase, the Cochrane Central Register of Controlled Trials, and the proceedings of major conferences for relevant investigations. To be eligible, studies had to be randomized, placebo-controlled trials reporting on the effects of antioxidant vitamins on cardiovascular outcomes. The primary outcome measures were major cardiovascular events, myocardial infarction, stroke, cardiac death, total death, and any adverse events.

The searches identified 293 articles of which 15 RCTs reporting data on 188209 participants met the inclusion criteria. In total, these studies reported 12749 major cardiovascular events, 6699 myocardial infarction, 3749 strokes, 14122 total death, and 5980 cardiac deaths. Overall, antioxidant vitamin supplementation, as compared to placebo, had no effect on major cardiovascular events (RR, 1.00; 95% CI, 0.96-1.03), myocardial infarction (RR, 0.98; 95% CI, 0.92-1.04), stroke (RR, 0.99; 95% CI, 0.93-1.05), total death (RR, 1.03; 95% CI, 0.98-1.07), cardiac death (RR, 1.02; 95% CI, 0.97-1.07), revascularization (RR, 1.00; 95% CI, 0.95-1.05), total CHD (RR, 0.96; 95% CI, 0.87-1.05), angina (RR, 0.98; 95% CI, 0.90-1.07), and congestive heart failure (RR, 1.07; 95% CI, 0.96 to 1.19).

The authors’ conclusion from these data could not be clearer: Antioxidant vitamin supplementation has no effect on the incidence of major cardiovascular events, myocardial infarction, stroke, total death, and cardiac death.

Few subjects in the realm of nutrition have attracted as much research during recent years as did antioxidants, and it is hard to think of a disease for which they are not recommended by this expert or another. Cardiovascular disease used to be the flag ship in this fleet of conditions; not so long ago, even the conventional medical wisdom sympathized with the notion that the regular supplementation of our diet with antioxidant vitamins might reduce the risk of cardiovascular disease and mortality.

Today, the pendulum has swung back, and it now seems to be mostly the alternative scene that still swears by antioxidants for that purpose. Nobody doubts that antioxidants have important biological functions, but this excellent meta-analysis quite clearly and fairly convincingly shows that buying antioxidant supplements is a waste of money. It does not promote cardiovascular health, it merely generates very expensive urine.

Even after all these years of full-time research into alternative medicine and uncounted exchanges with enthusiasts involved in this sector, I find the logic that is often applied in this field bewildering and the unproductiveness of the dialogue disturbing.

To explain what I mean, it be might best to publish a (fictitious, perhaps slightly exaggerated) debate between a critical thinker or scientist (S) and an uncritical proponent (P) of one particular form of alternative medicine.

P: Did you see this interesting study demonstrating that treatment X is now widely accepted, even by highly critical GPs at the cutting edge of health care?

S: This was a survey, not a ‘study’, and I never found the average GP “highly critical”. Surveys of this nature are fairly useless and they “demonstrate” nothing of real value.

P: Whatever, but it showed that GPs accept treatment X. This can only mean that they realise how safe and effective it is.

S: Not necessarily, GPs might just give in to consumer demand, or the sample was cleverly selected, or the question was asked in a leading manner, etc.

P: Hardly, because there is plenty of good evidence for treatment X.

S: Really? Show me.

P: There is this study here which proves that treatment X works and is risk-free.

S: The study was far too small to demonstrate safety, and it is wide open to multiple sources of bias. Therefore it does not conclusively show efficacy either.

P: You just say this because you don’t like its result! You have a closed mind!

In any case, it was merely an example! There are plenty more positive studies; do your research properly before you talk such nonsense.

S: I did do some research and I found a recent, high quality systematic review that arrived at a negative conclusion about the value of treatment X.

P: That review was done by sceptics who clearly have an axe to grind. It is based on studies which do not account for the intrinsic subtleties of treatment X. Therefore they are unfair tests of treatment X. These trials don’t really count at all. Every insider knows that! The fact that you cite it merely confirms that you do not understand what you are talking about.

S: It seems to me, that you like scientific evidence only when it confirms your belief. This, I am afraid, is what quacks tend to do!

P: I strongly object to being insulted in this way.

S: I did not insult you, I merely made a statement of fact.

P: If you like facts, you have to see that one needs to have sufficient expertise in treatment X in order to apply it properly and effectively. This important fact is neglected in all of those trials that report negative results; and that’s why they are negative. Simple! I really don’t understand why you are too stupid to understand this. Such studies do not show that treatment X is ineffective, but they demonstrate that the investigators were incompetent or hired with the remit to discredit treatment X.

S: I would have thought they are negative because they minimised bias and the danger of generating a false positive result.

P: No, by minimising bias, as you put it, these trials eliminated the factors that are important elements of treatment X.

S: Such as the placebo-effect?

P: That’s what you call it because you irrationally believe in reductionist science.

S: Science requires no belief, I think you are the believer here.

P: The fact is that scientists of your ilk negate all factors related to human interactions. Patients are no machines, you know, they need compassion; we clinicians know that because we work at the coal face of health care. Scientists in their ivory towers have no idea about patient care and just want science for science sake. This is not how you help patients. Show some compassion man!

S: I do know about the importance of compassion and care, but here we are discussing an entirely different topic, namely tests the efficacy or effectiveness of treatments, not patient-care. Let’s focus on one issue at a time.

P: You cannot separate things in this way. We have to take a holistic view. Patients are whole individuals, and you cannot do them justice by running artificial experiments. Every patient is different; clinical trials fail to account for this fact and are therefore fairly irrelevant to us and to our patients. Real life is very different from your imagined little experiments, you know.

S: These are platitudes that are nonsensical in this context and do not contribute anything meaningful to the present discussion. You do not seem to understand the methodology or purpose of a clinical trial.

P: That is typical! Whenever you run out of arguments, you try to change the subject or throw a few insults at me.

S: Not at all, I thought we were talking about clinical trials evaluating the effectiveness of treatment X.

P: That’s right; and they do show that it is effective, provided you consider those which are truly well-done by experts who know about treatment X and believe in it.

S: Not true. Only if you cherry-pick the data will you be able to produce an overall positive result for treatment X.

P: In any case, the real world results of clinical practice show very clearly that it works. It would not have survived for so long, if it didn’t. Nobody can deny that, and nobody should claim that silly little trials done in artificial circumstances are more meaningful than a wealth of experience.

S: Experience has little to do with reliable evidence.

P: To deny the value of experience is just stupid and clearly puts you in the wrong. I have shown you plenty of reliable evidence but you just ignore everything I say that does not go along with your narrow-minded notions about science; science is not the only way of knowing or comprehending things! Stop being obsessed with science.

S: No, you show me rubbish data and have little understanding of science, I am afraid.

P: Here we go again! I have had about enough of that and your blinkered arguments. We are going in circles because you are ignorant and arrogant. I have tried my best to show you the light, but your mind is closed. I offer true insight and you pay me back with insults. You and your cronies are in the pocket of BIG PHARMA. You are cynical, heartless and not interested in the wellbeing of patients. Next you will tell me to vaccinate my kids!

S: I think this is a waste of time.

P: Precisely! Everyone who has followed this debate will see very clearly that you are obsessed with reductionist science and incapable of considering the suffering of whole individuals. You want to deny patients a treatment that  really helps them simply because you do not understand how treatment X works. Shame on you!!!

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