One of the many issues that needs addressing about chiropractic is its safety. On this blog, we have had dozens of posts and debates on this topic. Today, I want to try and summarise them by providing a fictitious dialogue between a critic and a chiropractor.
Here we go:
Critic (CR): It seems to me that most of the chiros I talk to are convinced that their hallmark therapy, spinal manipulation, is risk-free.
Chiro (CH): Hallmark therapy? Not true! Osteopaths, physios, doctors they all use spinal manipulation.
CR: I know, but name me a profession that employs it more regularly than you chiros.
CH: In any case, it is as good as risk-free; nothing is totally devoid of risk, but chiropractic spinal manipulation (CSMT) is generally very safe, because we are better trained at it than the others.
CR: Do you say that because you believe it or because you know it?
CH: I know it.
CR: That means you have the evidence to prove it?
CH: Yes, of course. Over the years, I have treated over a thousand patients and never heard of any problems.
CR: Without a monitoring system of adverse events that occur after chiropractic spinal manipulation, this is pretty meaningless.
CH: Monitoring systems do not establish causality.
CR: No, but they are a start and can tell you whether there is a problem that requires looking into.
CH: Let me remind you please that the question of safety is foremost an issue for conventional medicine; this is why a monitoring system is useful for drugs. We actually do not need one, because CSMT is safe.
CR: Are you sure?
CR: The much-cited paper by Dabbs and Lauretti is out-dated, poor quality, and heavily biased. It provides no sound basis for an evidence-based judgement on the relative risks of cervical manipulation and NSAIDs. The notion that cervical manipulations are safer than NSAIDs is therefore not based on reliable data. Thus, it is misleading and irresponsible to repeat this claim. Is there not a better comparison for supporting your point?
CH: Not as far as I know. But you can trust our collective experience: CSMT is safe!
CR: Don’t you think that the issue is too important to rely purely on experience? Your collective experience can be very misleading, you know.
CH: Then tell me why chiros pay only a fraction of the insurance premium compared to doctors.
CR: Yes, that is the argument many chiros love. But it also is a very poor one: doctors treat patients who are often very ill, while chiros treat mostly sore backs. Don’t you think that explains a lot about the difference in insurance premiums?
CH: Perhaps, but if you claim CSMT to be harmful, how about you supporting your claim with evidence?
CR: Sure, the best is to review systematically all prospective studies on the topic; and if you do this, the conclusion is that data from prospective studies suggest that minor, transient adverse events occur in approximately half of all patients receiving spinal manipulation. The most common serious adverse events are vertebrobasilar accidents, disk herniation, and cauda equina syndrome. Estimates of the incidence of serious complications range from 1 per 2 million manipulations to 1 per 400,000. Given the popularity of spinal manipulation, its safety requires rigorous investigation.
CH: I bet these are studies done by people who are against chiropractic.
CR: No, actually the primary studies were all done by chiropractors.
CH: Minor transient problems! These are merely what we expect; things often need to get worse before they get better.
CR: Imagine that a drug company claims such BS about the side-effects of a new drug.
CH: But that’s different!
CR: In what way?
CH: Big Pharma is only out to make money.
CR: And chiros?
CH: That’s different too.
CR: What about the serious adverse events like vertebrobasilar accidents, disk herniation, and cauda equina syndrome? Are you going to deny they exist?
CH: Some of those serious complications, while rare, are conditions that existed prior to CSMT being performed with the practitioner missing it upon initial examination.
CR: How do you know?
CH: I know this from experience.
CR: I already told you that experience is unreliable.
CH: Then show me the evidence that I am wrong.
CR: No, you have to come up with the evidence; the burden of proof is evidently on your shoulders.
CH: Whatever! As long as there is no good evidence, I cannot accept that serious complications are a real problem.
CR: That’s just fine: you say “as long as there is no good evidence…” and, at the same time, you prevent good evidence from emerging by preventing a decent AE monitoring system.
CH: I always knew that one cannot have a reasonable discussion with you. I consider that I have won this debate; this issue is now closed.
Chronic rhinosinusitis (CRS) is a common disorder. This trial tested the efficacy of individualized homeopathy (IH) in comparison with placebo in patients with CRS.
This double-blind, randomized (1:1), placebo-controlled, preliminary trial (n = 62) was conducted at the National Institute of Homoeopathy, West Bengal, India. Primary outcome measure was the sino-nasal outcome test-20 (SNOT-20) questionnaire; secondary outcomes were the EQ-5D-5L questionnaire and EQ-5D-5L visual analogue scale scores, and five numeric rating scales (0-10) assessing intensity of sneezing, rhinorrhoea, post-nasal drip, facial pain/pressure, and disturbance in sense of smell, all measured at baseline and after the 2nd and 4th months of intervention. Group differences and effect sizes (Cohen’s d) were calculated on the intention-to-treat sample.
The two groups were comparable at baseline. Attrition rate was 6.5% (IH: 1, Placebo: 3). Although improvements in both primary and secondary outcome measures were higher in the IH group than placebo, with small to medium effect sizes, the group differences were statistically non-significant (all p > 0.05, unpaired t-tests). Calcarea carbonica, Lycopodium clavatum, Sulphur, Natrum muriaticum and Pulsatilla nigricans were the most frequently prescribed medicines. No harmful or unintended effects, homeopathic aggravations or any serious adverse events were reported from either group.
The authors who are affiliated with the following institutions:
- Department of Materia Medica, National Institute of Homoeopathy, Ministry of AYUSH, Govt. of India, Kolkata, West Bengal, India.
- Department of ENT, National Institute of Homoeopathy, Ministry of AYUSH, Govt. of India, Kolkata, West Bengal, India.
- Department of Paediatrics, National Institute of Homoeopathy, Ministry of AYUSH, Govt. of India, Kolkata, West Bengal, India.
- Department of Organon of Medicine and Homoeopathic Philosophy, National Institute of Homoeopathy, Ministry of AYUSH, Govt. of India, Kolkata, West Bengal, India.
- Department of Repertory, National Institute of Homoeopathy, Ministry of AYUSH, Govt. of India, Kolkata, West Bengal, India.
- Mahesh Bhattacharyya Homoeopathic Medical College and Hospital, Govt. of West Bengal, Howrah, West Bengal, India.
concluded that there was a small but non-significant direction of effect favoring homeopathy, which ultimately renders the trial as inconclusive. Rigorous trials and independent replications are recommended to arrive at a confirmatory conclusion.
Sorry, but this is the wrong conclusion. In the name of honesty and research integrity, it should read something like this:
Our study failed to show that IH has a significant effect on CRS.
But of course, this is no surprise. Why should IH work for CRS? The only remotely interesting finding here, in my view, is the fact that the authors noted not a single homeopathic aggravation (i. e. the occurrence of the ‘drug picture’ in a patient and thus a kind of homeopathic ‘proving’). Using IH, homeopaths would expect aggravations with some regularity. Could it be that homeopathic aggravations (and ‘provings’) are, like all effects of homeopathy, the result of misinterpretation, fantasy and wishful thinking? Investigating the issue systematically, we found already 17 years ago that this systematic review does not provide clear evidence that the phenomenon of homeopathic aggravations exists.
On this blog, I have discussed the adverse events (AEs) of spinal manipulative therapy (SMT) with some regularity, and we have seen that ~ 50% of patients who receive SMT from a chiropractor experience some kind of AE. In addition there are many serious complications. In my book, I discuss, apart from the better-known vascular accidents followed by a stroke or death, the following:
- atlantoaxial dislocation,
- cauda equina syndrome,
- cervical radiculopathy,
- diaphragmatic paralysis,
- disrupted fracture healing,
- dural sleeve injury,
- haemorrhagic cysts,
- muscle abscess,
- muscle abscess,
- neurologic compromise,
- oesophageal rupture
- soft tissue trauma,
- spinal cord injury,
- vertebral disc herniation,
- vertebral fracture,
- central retinal artery occlusion,
- Wallenberg syndrome,
- loss of vision,
- Horner’s syndrome.
Considering this long list, we currently have far too little reliable information. A recent publication offers further information on this important topic.
The aim of this study was to identify beliefs, perceptions and practices of chiropractors and patients regarding benign AEs post-SMT and potential strategies to mitigate them. Clinicians and patients from two chiropractic teaching clinics were invited to respond to an 11-question survey exploring their beliefs, perceptions and practices regarding benign AEs post-SMT and strategies to mitigate them.
A total of 39 clinicians (67% response rate) and 203 patients (82.9% response rate) completed the survey. The results show that:
- 97% of the chiropractors believed benign AEs occur.
- 82% reported their own patients have experienced an AE.
- 55% of the patients reported experiencing benign AEs post-SMT, with the most common symptoms being pain/soreness, headache and stiffness.
- 61.5% of the chiropractors reported trying a mitigation strategy with their patients.
- Yet only 21.2% of patients perceived their clinicians had tried any mitigation strategy.
- Chiropractors perceived that patient education is most likely to mitigate benign AEs, followed by soft tissue therapy and/or icing after SMT.
- Patients perceived stretching was most likely to mitigate benign AEs, followed by education and/or massage
The authors concluded that this is the first study comparing beliefs, perceptions and practices from clinicians and patients regarding benign AEs post-SMT and strategies to mitigate them. This study provides an important step towards identifying the best strategies to improve patient safety and improve quality of care.
The question that I have often asked before, and I am bound to ask again after seeing such results, is this:
If there were a drug that causes temporary pain/soreness, headache and stiffness in 55% of all patients (plus an unknown frequency of a long list of serious complications), while being of uncertain benefit, do you think it would still be on the market?
Opioid over-use has become a huge problem, particularly in the US. Proponents of complementary and alternative medicine (CAM) – or so-called alternative medicine (SCAM) as I prefer to call it these days – have been keen to suggest that they have a solution to this problem. But is this really true? So far, the evidence was slim, to say the least.
This systematic review evaluated the effectiveness of the integrative medicine (IM) approach or any of the CAM therapies to reduce or cease opioid use in CP patients.
The electronic searches yielded 5,200 citations. Twenty-three studies were selected. Eight studies were randomized controlled trials, 7 were retrospective studies, 4 studies were prospective observational, 3 were cross-sectional, and one was quasi-experimental. The majority of the studies showed that opioid use was reduced significantly after using IM. Cannabinoids were among the most commonly investigated approaches in reducing opioid use, followed by multidisciplinary approaches, cognitive-behavioural therapy (CBT), and acupuncture. The majority of the studies had limitations related to sample size, duration, and study design.
The authors concluded that there is a small but defined body of literature demonstrating positive preliminary evidence that the IM approach including CAM therapies can help in reducing opioid use. As the opioid crisis continues to grow, it is vital that clinicians and patients be adequately informed regarding the evidence and opportunities for IM/CAM therapies for CP.
The authors who are from the Canadian College of Naturopathic Medicine in Ontario, Canada (and who claim to have no conflict of interest) seem to have forgotten to discuss some not so unimportant details and questions:
- Why did they include studies with extremely weak designs in their review (such studies are likely to produce false positive findings)?
- Why did they consider treatments such as CBT as CAM (most experts would characterise them as conventional psychological therapies)?
- Why did they not conduct a separate analysis of the RCT-evidence (is it because that would not have generated the result they wanted?)?
My reading of the RCTs – the only type of study that might give a reliable answer to the question posed- is that they do not show a opioid-sparing effect of CAM use, particularly if we eliminate those studies that tested treatments which are not truly CAM. In any case, as I have said several times before, the way to avoid over-prescribing opioid is not through using more therapies of doubtful effectiveness but through prescribing less opioids. And to achieve that, doctors should just do what they learnt in medical school (at least I did all those years ago).
In so-called alternative medicine (SCAM), there are few notions more difficult to argue against than this one:
I KNOW IT WORKS BECAUSE I HAVE EXPERIENCED IT MYSELF!
Yet, it is this notion that we most often encounter when discussing with proponents of SCAM. To argue against it often gets an emotional response, not least because the SCAM proponent feels that we are implying that (s)he is either lying or stupid or both. Therefore, it is important, I feel, to keep on addressing this issue. So, let me once again explain why ineffective treatments often appear to be effective.
To make this less boring, let’s consider a concrete case, one where nobody (well, almost nobody) will get emotionally involved. Let’s consider a patient who has been suffering from recurring pain of an undiagnosed origin and experiences benefit after crystal healing, a form of SCAM for which there truly is not a jot of evidence.
Why then does (s)he experience less pain after consulting her crystal healer?
There is a myriad of reasons, and in this post I will borrow some from the literature of psychology:
- The patient might think his/her pain is less frequent without actual change; recall bias.
- The healer might have provided an explanation for the pain which the patient experiences as a symptomatic improvement.
- The healer could have convinced him/her that his/her pre-treatment pain was worse than it truly was; recall bias.
- The patient might report improvement in accord with what (s)he believes to be the healer’s hope and expectation; social desirability.
- The patient is prone to preferentially remembering improvements as opposed to worsening; recall bias.
- Patients might interpret ambiguous changes in symptoms as indications of improvement.
- Many symptoms disappear or improve on their own; natural history of the disease.
- Many symptoms fluctuate; natural history of the disease.
- Extremes become less extreme on re-testing; the phenomenon of ‘regression towards the mean’.
- Patients employ several therapies simultaneously and later misattribute an improvement to one treatment.
- Patients expect to improve; the placebo-effect.
- Patients are conditioned to improve; the placebo-effect.
- Improvement owing to enthusiasm of receiving a new intervention; the novelty effect.
- Improvement owing to enthusiasm of receiving an exotic therapy.
- Improvement due to the compassionate care and attention received.
- Improvement due to the time spent with the healer.
- Improvement due to the effort and resources invested by the patient.
All these phenomena (and several more, I am sure) work in concert and can generate a clinical outcome that makes ineffective therapies and even slightly harmful treatments appear to be effective. In any single case, it is impossible to decide what precisely brought about the improvement. The only way to make sure that the specific effects of the treatment (in my example the crystal therapy) was involved is to conduct one (better several) controlled clinical trials.
Excessive eccentric exercise of inadequately conditioned skeletal muscle results in focal sites of injury within the muscle fibres. These injuries cause pain which usually is greatest about 72 hours after the exercise. This type of pain is called delayed-onset muscle soreness (DOMS) and provides an accessible model for studying the effects of various treatments that are said to have anaesthetic activities; it can easily be reproducibly generated without lasting harm or ethical concerns.
In so-called alternative medicine (SCAM) DOMS is employed regularly to test treatments which are promoted for pain management. Thus several acupuncture trials using this method have become available. Yet, the evidence for the effects of acupuncture on DOMS is inconsistent which begs the question whether across all trials an effects emerges.
The aim of this systematic review therefore was to explore the effects of acupuncture on DOMS. Studies investigating the effect of acupuncture on DOMS in humans that were published before March 2020 were obtained from 8 electronic databases. The affected muscles, groups, acupuncture points, treatment sessions, assessments, assessment times, and outcomes of the included articles were reviewed. The data were extracted and analysed via a meta-analysis.
A total of 15 articles were included, and relief of DOMS-related pain was the primary outcome. The meta-analysis showed that there were no significant differences between acupuncture and sham/control groups, except for acupuncture for DOMS on day 1 (total SMD = -0.62; 95% CI = -1.12∼0.11, P < 0.05) by comparing with control groups.
The authors concluded that acupuncture for DOMS exhibited very-small-to-small and small-to-moderate effects on pain relief for the sham and no acupuncture conditions, respectively. Evidence indicating the effects of acupuncture on DOMS was little because the outcome data during the follow-up were insufficient to perform an effective meta-analysis.
A mere glance at the Forrest plot reveals that acupuncture is unlikely to have any effect on DOMS at all. The very small average effect that does emerge originates mainly from one outlier, the 2008 study by Itoh et al. This trial was published by three acupuncturists from the Department of Clinical Acupuncture and Moxibustion, Meiji University of Integrative Medicine, Kyoto, Japan. It has numerous weaknesses, for instance there are just 10 volunteers in each group, and can therefore be safely discarded.
In essence, this means that there is no good evidence that acupuncture is effective at reducing pain caused by DOMS.
This Cochrane review assessed the efficacy and safety of aromatherapy for people with dementia. The researchers included randomised controlled trials which compared fragrance from plants in an intervention defined as aromatherapy for people with dementia with placebo aromatherapy or with treatment as usual. All doses, frequencies and fragrances of aromatherapy were considered. Participants in the included studies had a diagnosis of dementia of any subtype and severity.
The investigators included 13 studies with 708 participants. All participants had dementia and in the 12 trials which described the setting, all were resident in institutional care facilities. Nine trials recruited participants because they had significant agitation or other behavioural and psychological symptoms in dementia (BPSD) at baseline. The fragrances used were:
- lavender (eight studies);
- lemon balm (four studies);
- lavender and lemon balm,
- lavender and orange,
- cedar extracts (one study each).
For six trials, assessment of risk of bias and extraction of results was hampered by poor reporting. Four of the other seven trials were at low risk of bias in all domains, but all were small (range 18 to 186 participants; median 66). The primary outcomes were:
- overall behavioural,
- psychological symptoms,
- adverse effects.
Ten trials assessed agitation using various scales. Among the 5 trials for which the confidence in the results was moderate or low, 4 trials reported no significant effect on agitation and one trial reported a significant benefit of aromatherapy. The other 5 trials either reported no useable data or the confidence in the results was very low. Eight trials assessed overall BPSD using the Neuropsychiatric Inventory and there was moderate or low confidence in the results of 5 of them. Of these, 4 reported significant benefit from aromatherapy and one reported no significant effect.
Adverse events were poorly reported or not reported at all in most trials. No more than two trials assessed each of our secondary outcomes of quality of life, mood, sleep, activities of daily living, caregiver burden. There was no evidence of benefit on these outcomes. Three trials assessed cognition: one did not report any data and the other two trials reported no significant effect of aromatherapy on cognition. The confidence in the results of these studies was low.
The authors reached the following conclusions: We have not found any convincing evidence that aromatherapy (or exposure to fragrant plant oils) is beneficial for people with dementia although there are many limitations to the data. Conduct or reporting problems in half of the included studies meant that they could not contribute to the conclusions. Results from the other studies were inconsistent. Harms were very poorly reported in the included studies. In order for clear conclusions to be drawn, better design and reporting and consistency of outcome measurement in future trials would be needed.
This is a thorough review. It makes many of the points that I so often make regarding SCAM research:
- too many of the primary studies are badly designed;
- too many of the primary studies are too small;
- too many of the primary studies are poorly reported;
- too many of the primary studies fail to mention adverse effects thus violating research ethics;
- too many of the primary studies are done by pseudo-scientists who use research for promotion rather than testing hypotheses.
It is time that SCAM researchers, ethic review boards, funders, editors and journal reviewers take these points into serious consideration – if only to avoid clinical research getting a bad reputation and losing the support of patients without which it cannot exist.
About one in three individuals have elevated blood pressure. This is bad news because hypertension is one of the most important risk factors for cardiovascular events like strokes and heart attacks. Luckily, there are many highly effective approaches for treating elevated blood pressure (diet, life-style, medication, etc.), and the drug management of hypertension has improved over the last few decades.
But unfortunately all anti-hypertensive drugs have side-effects and some patients look towards so-called alternative medicine (SCAM) to normalise their blood pressure. Therefore, we have to ask: are SCAMs effective treatments for hypertension? Because of the prevalence of hypertension, this is a question of great importance for public health.
In 2005, I addressed the issue by publishing a review entitled ‘Complementary/alternative medicine for hypertension: a mini-review‘. Here is its abstract:
Many hypertensive patients try complementary/alternative medicine for blood pressure control. Based on extensive electronic literature searches, the evidence from clinical trials is summarised. Numerous herbal remedies, non-herbal remedies and other approaches have been tested and some seem to have antihypertensive effects. The effect size is usually modest, and independent replications are frequently missing. The most encouraging data pertain to garlic, autogenic training, biofeedback and yoga. More research is required before firm recommendations can be offered.
Since the publication of this paper, more systematic reviews have become available. In order to get an overview of this evidence, I conducted a few simple Medline searches for systematic reviews (SRs) of SCAM published between 2005 and today. I included only SRs that were focussed on just one specific therapy as a treatment of just one specific condition, namely hypertension (omitting SRs with titles such as ‘Alternative treatments for cardiovascular conditions’). Reviews on prevention were also excluded. Here is what I found (the conclusions of each SR is quoted verbatim):
- A 2020 SR of auricular acupressure including 18 RCTs: The results demonstrated a favorable effect of auricular acupressure to reduce blood pressure and improve sleep in patients with hypertension and insomnia. Further studies to better understand the acupoints and intervention times of auricular acupressure are warranted.
- A 2020 SR of Chinese herbal medicines (CHM) including 30 studies: CHM combined with conventional Western medicine may be effective in lowering blood pressure and improving vascular endothelial function in patients with hypertension.
- A 2020 SR of Tai chi including 28 RCTs: Tai Chi could be recommended as an adjuvant treatment for hypertension, especially for patients less than 50 years old.
- A 2020 SR of Tai chi including 13 trials: Tai chi is an effective physical exercise in treating essential hypertension compared with control interventions.
- A 2020 SR of Tai chi including 31 controlled clinical trials: Tai Ji Quan is a viable antihypertensive lifestyle therapy that produces clinically meaningful BP reductions (i.e., 10.4 mmHg and 4.0 mmHg of SBP and DBP reductions, respectively) among individuals with hypertension.
- A 2020 SR of pycnogenol including 7 trials: the present meta-analysis does not suggest any significant effect of pycnogenol on BP.
- A 2019 SR of Policosanol including 19 studies: Policosanol could lower SBP and DBP significantly; future long term studies are required to confirm these findings in the general population.
- A 2019 SR of dietary phosphorus including 14 studies: We found no consistent association between total dietary phosphorus intake and BP in adults in the published literature nor any randomized trials designed to examine this association.
- A 2019 SR of ginger including 6 RCTs: ginger supplementation has favorable effects on BP.
- A 2019 SR of corn silk tea (CST) including 5 RCTs: limited evidence showed that CST plus antihypertensive drugs might be more effective in lowering blood pressure compared with antihypertensive drugs alone.
- A 2019 SR of blood letting including 7 RCTs: no definite conclusions regarding the efficacy and safety of BLT as complementary and alternative approach for treatment of hypertension could be drew due to the generally poor methodological design, significant heterogeneity, and insufficient clinical data.
- A 2019 SR of Xiao Yao San (XYS) including 17 trials: XYS adjuvant to antihypertensive drugs maybe beneficial for hypertensive patients in lowering BP, improving depression, regulating blood lipids, and inhibiting inflammation.
- A 2019 SR of Chinese herbal medicines including 9 RCTs: Chinese herbal medicine as complementary therapy maybe beneficial for postmenopausal hypertension.
- A 2019 Cochrane review of guided imagery including 2 trials: There is insufficient evidence to inform practice about the use of guided imagery for hypertension in pregnancy.
- A 2019 Cochrane review of acupuncture including 22 RCTs: At present, there is no evidence for the sustained BP lowering effect of acupuncture that is required for the management of chronically elevated BP.
- A 2019 SR of wet cupping including 7 RCTs: no firm conclusions can be drawn and no clinical recommendations made.
- A 2019 SR of transcendental meditation (TM) including 9 studies: TM was associated with within-group (but not between-groups) improvements in BP.
- A 2019 SR of yoga including 49 trials: yoga is a viable antihypertensive lifestyle therapy that produces the greatest BP benefits when breathing techniques and meditation/mental relaxation are included.
- A 2018 SR of mindfulness-based stress reduction (MBSR) including 5 studies: The MBSR program is a promising behavioral complementary therapy to help people with hypertension lower their blood pressure
- A 2018 SR of beetroot juice (BRJ) including 11 studies: BRJ supplementation should be promoted as a key component of a healthy lifestyle to control blood pressure in healthy and hypertensive individuals.
- A 2018 SR of taurine including 7 studies: ingestion of taurine at the stated doses and supplementation periods can reduce blood pressure to a clinically relevant magnitude, without any adverse side effects.
- A 2018 SR of acupuncture including 30 RCTs: there is inadequate high quality evidence that acupuncture therapy is useful in treating hypertension.
- A 2018 SR of co-enzyme Q10 including 17 RCTs: CoQ10 supplementation may result in reduction in SBP levels, but did not affect DBP levels among patients with metabolic diseases.
- A 2018 SR of a traditional Chinese formula Longdanxiegan decoction (LDXGD) including 9 trials: Due to poor methodological quality of the included trials, as well as potential reporting bias, our review found no conclusive evidence for the effectiveness of LDXGD in treating hypertension.
- A 2018 SR of viscous fibre including 22 RCTs: Viscous soluble fiber has an overall lowering effect on SBP and DBP.
- A 2017 SR of yoga breathing exercise (pranayama) including 13 studies: The pranayama’s effect on BP were not robust against selection bias due to the low quality of studies. But, the lowering BP effect of pranayama is encouraging.
- A 2017 SR of dietary nitrate supplementation including 13 trials: Positive effects of medium-term dietary nitrate supplementation on BP were only observed in clinical settings, which were not corroborated by more accurate methods such as 24-h ambulatory and daily home monitorings.
- A 2017 SR of Vitamin D supplementation including 8 RCTs: vitamin D is not an antihypertensive agent although it has a moderate SBP lowering effect.
- A 2017 SR of pomegranate including 8 RCTs: The limited evidence from clinical trials to date fails to convincingly show a beneficial effect of pomegranate on blood pressure
- A 2017 SR of ‘forest bathing’ including 20 trials: This systematic review shows a significant effect of Shinrin-yoku on reduction of blood pressure.
- A 2017 SR of Niuhuang Jiangya Preparation (NHJYP) including 12 RCTs: Our review indicated that NHJYP has some beneficial effects in EH patients with liver-yang hyperactivity and abundant phlegm-heat syndrome.
- A 2017 SR of Chinese medicines (CM) including 24 studies: CM might be a promising approach for the elderly with isolated systolic hypertension, while the evidence for CM employed alone was insufficient.
- A 2017 SR of beetroot juice including 22 RCTs: Our results demonstrate the blood pressure-lowering effects of beetroot juice and highlight its potential NO3-independent effects.
- A 2017 SR of blueberry including 6 RCTs: the results from this meta-analysis do not favor any clinical efficacy of blueberry supplementation in improving BP
- A 2016 Cochrane review of co-enzyme Q10 including 3 RCTs: This review provides moderate-quality evidence that coenzyme Q10 does not have a clinically significant effect on blood pressure.
- A 2016 SR of Nigella sativa including 11 RCTs: short-term treatment with N. sativa powder can significantly reduce SBP and DBP levels.
- A 2016 SR of vitamin D3 supplementation including 30 RCTs: Supplementation may be beneficial at daily doses >800 IU/day for <6 months in subjects ≥50 years old.
- A 2016 SR of anthocyanin supplementation including 6 studies: results from this meta-analysis do not favor any clinical efficacy of supplementation with anthocyanins in improving blood pressure.
- A 2016 SR of flaxseed including 15 trials: This meta-analysis of RCTs showed significant reductions in both SBP and DBP following supplementation with various flaxseed products.
- A 2016 SR of massage therapy including 9 RCTs: This systematic review found a medium effect of massage on SBP and a small effect on DBP in patients with hypertension or prehypertension.
- A 2015 SR of massage therapy including 24 studies: There is some encouraging evidence of massage for essential hypertension.
- A 2015 SR of transcendental meditation (TM) including 12 studies: an approximate reduction of systolic and diastolic BP of -4.26 mm Hg (95% CI=-6.06, -2.23) and -2.33 mm Hg (95% CI=-3.70, -0.97), respectively, in TM groups compared with control groups.
- A 2015 SR of Zhen Wu Decoction (ZWD) including 7 trials: This systematic review revealed no definite conclusion about the application of ZWD for hypertension due to the poor methodological quality, high risk of bias, and inadequate reporting on clinical data.
- A 2015 SR of acupuncture including 23 RCTs: Our review provided evidence of acupuncture as an adjunctive therapy to medication for treating hypertension, while the evidence for acupuncture alone lowing BP is insufficient.
- A 2015 SR of xuefu zhuyu decoction (XZD) including 15 studies: This meta-analysis provides evidence that XZD is beneficial for hypertension.
- A 2015 SR of Shenqi pill including 4 RCTs: This systematic review firstly provided no definite evidence for the efficacy and safety of Shenqi pill for hypertension based on the insufficient data.
- A 2015 SR of Jian Ling Decoction (JLD) including 10 trials: Owing to insufficient clinical data, it is difficult to draw a definite conclusion regarding the effectiveness and safety of JLD for essential hypertension.
- A 2015 SR of Chinese herbal medicines (CHM) including 5 trials: No definite conclusions about the effectiveness and safety of CHM for resistant hypertension could be drawn.
- A 2015 SR of Chinese medicines (CM) including 27 RCTs: When combined with Western medines, CM as a complementary treatment approach has certain effects for the control of hypertension and protection of target organs.
- A 2015 SR of berberine including 17 RCTs: This study indicates that berberine has comparable therapeutic effect on type 2 DM, hyperlipidemia and hypertension with no serious side effect.
- A 2015 SR of garlic including 9 double-blind trials: Although evidence from this review suggests that garlic preparations may lower BP in hypertensive individuals, the evidence is not strong.
- A 2015 SR of chlorogenic acids (CGAs) including 5 studies: CGA intake causes statistically significant reductions in systolic and diastolic blood pressures.
- A 2014 SR of omega-3 fatty acid supplementation including 70 RCTs: provision of EPA+DHA reduces systolic blood pressure, while provision of ≥2 grams reduces diastolic blood pressure.
- A 2014 SR of green tea including 20 RCTs: Green tea intake results in significant reductions in systolic blood pressure
- A 2014 SR of probiotics including 9 studies: consuming probiotics may improve BP by a modest degree, with a potentially greater effect when baseline BP is elevated, multiple species of probiotics are consumed, the duration of intervention is ≥8 weeks, or daily consumption dose is ≥10(11) colony-forming units.
- A 2014 SR of yoga including 17 trials: The evidence for the effectiveness of yoga as a treatment of hypertension is encouraging but inconclusive.
- A 2014 SR of yoga including 7 RCTs: very low-quality evidence was found for effects of yoga on systolic and diastolic blood pressure.
- A 2014 SR of yoga including 120 studies: yoga is an effective adjunct therapy for HPT and worthy of inclusion in clinical guidelines.
- A 2014 SR of moxibustion: a beneficial effect of using moxibustion interventions on KI 1 to lower blood pressure compared to antihypertensive drugs.
- A 2014 SR of acupuncture including 4 sham-controlled RCTs: acupuncture significantly lowers blood pressure in patients taking antihypertensive medications.
- A 2014 SR of Tuina including 7 RCTs: The findings from our review suggest that Tuina might be a beneficial adjuvant for patients with EH
- A 2014 SR of ‘kidney tonifying’ (KT) Chinese herbal mixture including 6 studies: Compared with antihypertensive drugs alone, KT formula combined with antihypertensive drugs may provide more benefits for patients with SH.
- A 2014 SR of Tongxinluo capsule including 25 studies : There is some but weak evidence about the effectiveness of TXL in treating patients with hypertension.
- A 2014 SR of moxibustion including 5 RCTs: no confirm conclusion about the effectiveness and safety of moxibustion as adjunctive treatment for essential hypertension could be made
- A 2013 SR of Qi Ju Di Huang Wan (QJDHW) including 10 RCTs: QJDHW combined with antihypertensive drugs might be an effective treatment for lowering blood pressure and improving symptoms in patients with essential hypertension.
- A 2013 SR of yoga including 17 studies: Yoga can be preliminarily recommended as an effective intervention for reducing blood pressure.
- A 2013 SR of Tianma Gouteng Yin (TGY) including 22 RCTs: No confirmed conclusion about the effectiveness and safety of TGY as adjunctive treatment for essential hypertension … could be made.
- A 2013 SR of Zhen Gan Xi Feng Decoction (ZGXFD) including 6 RCTs: ZGXFD appears to be effective in improving blood pressure and hypertension-related symptoms for EH
- A 2013 SR of Tianmagouteng decoction including 9 RCTs: Tianmagouteng decoction can decrease both systolic and diastolic blood pressure.
- A 2013 SR of fish oil including 17 RCTs: The small but statistically significant effects of fish-oil supplements in hypertensive participants in this review have important implications for population health and lowering the risk of stroke and ischaemic heart disease.
- A 2013 SR of acupuncture including 35 RCTs: While there are some evidences that suggest potential effectiveness of acupuncture for hypertension, the results were limited by the methodological flaws of the studies.
- A 2013 SR of yoga including 6 studies: There is some encouraging evidence of yoga for lowering SBP and DBP.
- A 2012 SR of spinal manipulation therapy (SMT) including 10 studies: There is currently a lack of low bias evidence to support the use of SMT as a therapy for the treatment of
- A 2012 SR of vitamin C including 29 trials: In short-term trials, vitamin C supplementation reduced SBP and DBP.
- A 2012 SR of magnesium supplementation including 22 trials: magnesium supplementation appears to achieve a small but clinically significant reduction in BP, an effect worthy of future prospective large randomised trials using solid methodology.
- A 2012 SR of Banxia Baizhu Tianma Decoction (BBTD) including 16 RCTs: There is encouraging evidence of BBTD for lowering SBP, but evidence remains weak.
- A 2012 SR of Liu Wei Di Huang Wan (LWDHW) including 6 RCTs: LWDHW combined with antihypertensive drugs appears to be effective in improving blood pressure and symptoms in patients with essential hypertension.
- A 2012 SR of aromatherapy including 5 studies: The existing trial evidence does not show convincingly that aromatherapy is effective for hypertension.
- A 2012 empty Cochrane review: As no trials could be identified, no conclusions can be made about the role of TGYF in the treatment of primary hypertension.
- A 2012 SR of yoga including 10 studies: Not only does yoga reduce high BP but it has also been demonstrated to effectively reduce blood glucose level, cholesterol level, and body weight, major problems affecting the American society.
- A 2011 SR of L-arginine including 11 RCTs: This meta-analysis provides further evidence that oral L-arginine supplementation significantly lowers both systolic and diastolic BP.
- A 2011 SR of soy isoflavones including 14 RCTs: Soy isoflavone extracts significantly decreased SBP but not DBP in adult humans, and no dose-response relationship was observed.
- A 2010 SR of moxibustion including 4 RCTs: There is insufficient evidence to suggest that moxibustion is an effective treatment for hypertension.
- A 2010 SR of acupunctures including 20 studies: Because of the paucity of rigorous trials and the mixed results, these findings result in limited conclusions. More rigorously designed and powered studies are needed.
- A 2010 SR of cupping including 3 trials: the evidence is not significantly convincing to suggest cupping is effective for treating hypertension.
- A 2010 empty Cochrane review: There is insufficient evidence to support the benefit of Roselle for either controlling or lowering blood pressure in patients with hypertension.
- A 2009 SR of acupuncture including 11 RCTs: the notion that acupuncture may lower high BP is inconclusive.
- A 2008 SR of transcendental meditation including 9 studies: The regular practice of Transcendental Meditation may have the potential to reduce systolic and diastolic blood pressure by approximately 4.7 and 3.2 mm Hg, respectively.
- A 2008 SR of relaxation therapies including 25 trials: the evidence in favour of a causal association between relaxation and blood pressure reduction is weak.
- A 2007 SR of qigong including 12 RCTs: There is some encouraging evidence of qigong for lowering SBP, but the conclusiveness of these findings is limited.
- A 2007 SR of co-enzyme Q10 including 12 trials: coenzyme Q10 has the potential in hypertensive patients to lower systolic blood pressure by up to 17 mm Hg and diastolic blood pressure by up to 10 mm Hg without significant side effects.
- A 2007 SR of stress reduction programs including 106 studies: Available evidence indicates that among stress reduction approaches, the Transcendental Meditation program is associated with significant reductions in BP.
- A 2006 Cochrance review of magnesium supplementation including 12 RCTs: the evidence in favour of a causal association between magnesium supplementation and blood pressure reduction is weak and is probably due to bias.
- A 2006 Cochrane review of calcium supplementation including 13 RCTs: evidence in favour of causal association between calcium supplementation and blood pressure reduction is weak and is probably due to bias.
ALMOST 100 NEW SRs!
To be honest, if I had known the volume of the material, I would probably not have tackled this task. Since the publication of my mini-review in 2005, there has been an explosion of similar papers:
- 1 in 2005
- 2 in 2006
- 3 in 2007
- 2 in 2008
- 1 in 2009
- 4 in 2010
- 2 in 2011
- 8 in 2012
- 8 in 2013
- 12 in 2014
- 12 in 2015
- 6 in 2016
- 9 in 2017
- 7 in 2018
- 12 in 2019
As this is based on very simple Medline searches, the list is certainly not complete. Despite this fact, several conclusions seem to emerge:
- There is no shortage of SCAMs that have been tested for hypertension.
- Most seem to have positive effects; in many cases, they seem too good to be true.
- Many of the SRs are of poor methodological quality, based on poor quality primary studies, published in less than reputable journals. Some SRs, for instance, include studies without a control group which is likely to lead to false-positive overall conclusions about the effectiveness of the SCAM in question.
- In recent years, there are more and more SRs by Chinese authors focussed on Chinese herbal mixtures that are unknown and unobtainable outside China. These SRs are invariably based on studies published in Chinese language in journals that are inaccessible. This means it is almost impossible for the reader, reviewer or editor to check their accuracy. The reliability of the conclusions of these SRs must therefore be doubted.
- Most of the primary studies included in the SRs lack long-term data. Thus the usefulness of the SCAM in question is questionable.
- With several of the SCAMs, the dose of the treatment and treatment schedule is less than clear. For instance, one might ask how frequently a patient should have acupuncture to control her hypertension.
- Some of the SCAMs assessed in these SRs seem of doubtful practicality. For instance, it might not be feasible nor economical for patients to receive regular acupuncture to manage their blood pressure.
- Several contradictions emerge from some of the SRs of the same modality. This is particularly confusing because SRs are supposed to be the most reliable type of evidence. In most instances, however, the explanation can easily be found by looking at the quality of the SRs. If SRs are based on uncontrolled studies, or if they fail to critically evaluate the reliability of the included primary trials, they are likely to arrive at conclusions that are too positive. Examples for such confusion are the multiple SRs of co-enzyme Q10 or the three yoga SRs of 2014.
- Because of this confusion, SCAM advocates are able to select false-positive SRs to support their opinion that SCAM is effective.
- Despite a substantial amount of positive evidence, none of the SCAMs have become part of the routine in the management of hypertension. A 2013 statement by the American Heart Association entitled Beyond medications and diet: alternative approaches to lowering blood pressure: a scientific statement from the american heart association concluded that it is reasonable for all individuals with blood pressure levels >120/80 mm Hg to consider trials of alternative approaches as adjuvant methods to help lower blood pressure when clinically appropriate. A suggested management algorithm is provided, along with recommendations for prioritizing the use of the individual approaches in clinical practice based on their level of evidence for blood pressure lowering, risk-to-benefit ratio, potential ancillary health benefits, and practicality in a real-world setting.
What lessons might this brief overview of SRs teach us? I think the following points are worth considering:
- Systematic reviews are the best type of evidence we have for estimating the effectiveness of treatments. But it is essential that they include a strong element of CRITICAL evaluation of the primary studies. Without it, a SR is incomplete and potentially counter-productive.
- The primary studies of SCAM are far too often of poor quality. This means that researchers should thrive to improve the rigour of their investigations.
- Both poor-quality primary studies and uncritically conducted SRs are prone to yielding findings that are too good to be true.
- Editors and reviewers have a responsibility to prevent the publication of trials and SRs that are of poor quality and thus likely to mislead us.
- Those SCAMs that have shown promising effects on hypertension (for instance Tai chi) should now be submitted to further independent scrutiny to find out whether their efficacy and usefulness can be confirmed, for instance, by 24-h ambulatory and daily home blood pressure monitoring and studies testing their acceptability in real life settings. Subsequently, we ought to determine whether the SCAM in question can be reasonably integrated in routine blood pressure management.
- The adjunctive use of a SCAM that has been proven to be effective and practical seems a reasonable approach. Yet, it requires proper scientific scrutiny.
- There is a paucity of cost-effectiveness studies and investigations of the risks of SCAM which needs to be addressed before any SCAM is considered for routine care.
When chiropractors try to play medical doctors, their patients are in danger. When they try to play epidemiologists, we might all be in danger. Already in April 2020, the Australian ‘Patrons of Chiropractic Science’ issued a press release on COVID 19 stating:
Good function of the body’s joints, particularly within the spine, may improve neurological function, which is important for an effective natural immune system. Treatment by a qualified and experienced chiropractor offers one of the most effective methods to improve and maintain good spinal joint function. The chiropractic profession attends to many patients, and like all other health workers, the profession truly cares for the welfare of every individual.
Now they have gone further. Their press release of 18/8/2020 states amongst other things:
- Approximately 1.5% of those infected with SARS-CoV-2 may die; all people with a compromised immune system, that being the aged or those suffering a co-morbidity;
- 98.5% of those infected with the COVID-19 virus suffer either no symptoms, mild symptoms or treatable symptoms no worse than seasonal influenza;
- COVID-19 positive test numbers are largely irrelevant, as 98.5% of those testing positive will simply develop natural immunity and recover as the virus moves through the population. Recent studies by the UK based Centre for Evidence Based Medicine confirms increased COVID testing is the primary reason for increased case numbers, which have little relationship to mortality. The focus on case numbers is again designed to engender public fear and compliance;
Patrons of Chiropractic Science demands that the Victorian Government and its senior health officials cease distorting facts, stop blaming Victorian non-compliance for the increased positive testing numbers, and assume full responsibility for the aged care deaths and the current economic damage.
Simple facts: it is critical and more effective to isolate and protect the high-risk groups, effectively quarantine return travellers, but cease the illogical isolation of the vast majority of the population who are not at risk as the virus naturally circulates, and allow them to recommence working to save many businesses and initiate economic recovery.
Implying that regular chiropractic manipulations improve immunity or protect people from the corona virus is bad enough. But the new press release is worse:
- It is not true that only people with impaired immune systems, of old age, or affected by other diseases die of COVID 19.
- It is not true that all of the 98.5% who do not die have treatable symptoms not worse than a flu; an undefined percentage of the survivors suffer from very severe and sometimes long-lasting conditions.
- It is not true that 98.5% of those testing positive will simply develop natural immunity and recover; many will not recover completely, and the question whether mildly affected individuals develop immunity and for how long is as yet unanswered.
- It is not true that COVID testing results are unrelated to mortality; the figures need, of course, careful interpretation; the percentage of positive tests per number of tests done, for instance, should be independent of the frequency of testing.
- It is not true that the vast majority of the population are not at risk, if the virus were to circulate naturally.
All this looks to me as though the ‘Patrons of Chiropractic Science’ are in urgent need of learning some science. Meanwhile, it would be most helpful, if they could keep quiet.
At present, we see a wave of promotion of Traditional Chinese Medicine (TCM) as a treatment of corona-virus infections. In this context, we should perhaps bear in mind that much of the Chinese data seem to be less than reliable. Moreover, I find it important to alert people to a stern warning recently published by two Australian experts. Here is the crucial passage from their paper:
We wish to highlight significant concerns regarding the association between traditional herbal medicines and severe, non-infective interstitial pneumonitis and other aggressive pulmonary syndromes, such as diffuse alveolar haemorrhage and ARDS which have emerged from Chinese and Japanese studies particularly during the period 2017−2019. Initially the association between traditional herbal therapies and pneumonitis was based on isolated case reports. These included hypersensitivity pneumonitis associated with the use of traditional Chinese or Japanese medicines such as Sai-rei-to, Oren-gedoku-to, Seisin-renshi-in and Otsu-ji-to (9 references in supplemental file). Larger cohorts and greater numbers now support this crucial relationship. In a Japanese cohort of 73 patients, pneumonitis development occurred within 3 months of commencing traditional medicine in the majority of patients , while a large report from the Japanese Ministry of Health, Labor and Welfare, described more than 1000 cases of lung injury secondary to traditional medications, the overwhelming majority of which (852 reports) were described as ‘interstitial lung disease .
Currently the constituent of traditional herbal medicines which is considered most likely to underlie causation of lung disease is Scutellariae Radix also known as Skullcap or ou-gon, which has been implicated through immunological evidence of hypersensitivity as well as circumstantial evidence, being present in all of those medicines outlined above . Notably, skullcap is a constituent of QPD as used and described in the paper by Ren et al. relating to COVID-19 . Scutellariae Radix-induced ARDS and COVID-19 disease share the same characteristic chest CT changes such as ground-glass opacities and airspace consolidation, therefore distinguishing between lung injury due to SARS-CoV-2 and that secondary to TCM may be very challenging. The potential for iatrogenic lung injury with TCM needs to be acknowledged …
Morbidity and mortality from COVID-19 are almost entirely related to lung pathology . Factors which impose a burden on lung function such as chronic lung disease and smoking are associated with increased risk for a poor outcome. Severe COVID-19 may be associated with a hypersensitivity pneumonitis component responsive to corticosteroid therapy . Against this background the use of agents with little or no evidence of clinical efficacy and which have been significantly implicated in causing interstitial pneumonitis that could complicate SARS-CoV-2 infection, should be considered with extreme caution.
In conclusion, the benefits of TCM in the treatment of COVID-19 remain unproven and may be potentially deleterious. We recognise that there is currently insufficient evidence to prove the role of TCM in the causation of interstitial pneumonitis, however the circumstantial data is powerful and it would seem prudent to avoid these therapies in patients with known or suspected SARS-CoV-2 infection, until the evidence supports their use.
Declaration of Competing Interest: There are no conflicts to declare.