Monthly Archives: February 2024
The 29th of February is an unusual date, and I will do something fittingly unusual today – something that I have never done before: I will with a heavy heart resign from an organisation of skeptics.
After I had observed the self-destructive debates within the GWUP for almost one year without saying a single word about it (hoping they would soon dissolve into thin air), I published a comment a few days ago. Soon after, I was aggressed, defamed, wrongly denounced as an anti-Semite, and blackmailed by leading members of that organisation.
Confronted with these events, it was inevitable that I would have doubts about my previous plan to remain a member until the upcoming general assembly in May. While I was contemplating, I received a Tweet on 27/2/2024 from someone under the pseudonym Endgegner der Kommentarspalten; it included this sentence:
Einer der verschwörungsideologischen Clowns, die seit gut einem Jahr Kulturkrieg in der GWUP mit rechtsextremen Talking Points spielen und Märchen von einem “woken Putsch” herbeiphantasieren?
My translation:
One of the conspiracy ideological clowns who have been playing culture war in the GWUP for a good year with right-wing extremist talking points and fantasising about a “woke coup”?
Next, I watched a long discussion on youtube between the new chair of the GWUP, my accuser (Bartoschek) and Sebastian Hirsch. There I learnt that the latter is, in fact, nobody else than Endgegner der Kommentarspalten. He was recently put in charge of Twitter account for GWUP by the chair.
At this point, I lost the hope that the GWUP might be saved. It seems to be in the hand of thugs who call not me personally but their opponents ‘ideological clowns who have been playing culture war’. They claim that they want to keep politics out of the GWUP, yet almost all they do is engaging in politics.
Since the former formidable chair, Amardeo Sarma, left and the rift started, the GWUP has done nothing wothwhile, as far as I can see. On the GWUP website, we are told that (my translation):
- The GWUP aims at promoting science and scientific thinking.
- The GWUP investigates parascientific theories according to the current state of scientific knowledge and reports publicly and comprehensibly on its findings.
- The GWUP aims to disseminate scientific and critical thinking and scientific methods, explain them in a generally understandable way and clearly distinguish real science from parascience. The GWUP thus wants to contribute to reducing society’s susceptibility to parascientific ideas and promises.
- The GWUP is an internationally orientated society. It is happy to work with like-minded individuals, organisations and institutions.
GWUP stands for ‘Gesellschaft zur wissenschaftlichen Untersuchung von Parawissenschaften’ (Society for the Scientific Investigation of Parasciences). The people currently in charge claim to be scientists but most of them are not (talking about science or publishing books for the lay reader about it does not, in my view, make you a scientist!). The leadership of the GWUP, it seems to me, is currently dominated by small-minded inward-looking guys with no international perspective who are in the middle of a mega-ego trip.
Instead of fighting parascience, they feel entitled to fight their colleagues. Instead of doing their job, they open the door to parascience. Instead of being scientists, they are using skepticism as an excuse for their machinations. Instead of running a scientific organisation, they turned it into a veritable kindergarden. In a nutshell: to the utmost delight of German parascientists, they have completely lost the plot.
I do not believe that the general assembly can turn things around. More likely, matters will get worse and it will come to a complete split. Personally, I cannot – not even until May – remain a member of an organisation where the man officially put in charge of the Twitter account feels entitled to collectively call his opponents ‘ideological clowns who have been playing culture war’. This remark in itself might not be all that significant but, for me, it is the ‘last straw’ and a symptom of a deep and irreversible rot.
So, I have come to the conclusion that I can do my work better without any further GWUP-hindrance. Therefore, I will now email my resignation as a member of the GWUP.
Jennifer Jacobs started publishing peer-reviewed papers on homeopathy in the early 1990s. This happens to be around the same time as I did. So, we both have about 30 years of research into homeopathy behind us.
Jennifer just authored a paper entitled “Thirty Years of Homeopathic Research – Lessons Learned“. Here is its abstract:
Conducting double-blind randomized controlled trials is difficult, even in the allopathic medical system. Doing so within the paradigm of classical homeopathy is even more challenging. More than thirty years of experience in carrying out such trials has taught me much about the pitfalls to avoid as well as the factors that can lead to success. The initial steps of putting together a research protocol, securing funding, and obtaining human subjects’ approval can be daunting. After that comes developing questionnaires and surveys, hiring study personnel, and recruitment of subjects. The actual implementation of the research comes with its own set of possible missteps. Sample size determination, entry criteria, as well as type, frequency and duration of treatment are all crucial. Finally, statistical analysis must be performed to a high standard and a manuscript prepared to submit for publication. Even then there can be one or more manuscript revisions to make, based on feedback from reviewers, before a study is actually published. The entire process can take at least two years and is usually much longer.
Mistakes at any one of these steps can damage the outcome, as well as the impact of the study. With examples from my body of research, I will discuss some of the things that I wish I had done differently, as well as those that turned out to be correct. Homeopathic research is held to a much higher standard than conventional trials. Any flaws in study design, implementation, and analysis can be used by critics to negate the results. I am hopeful that the next generation of homeopathic researchers will learn from my experiences and carry on with great success.
Jennifer’s example motivated me to follow suit and contribute some very brief thoughts about my 30 years of homeopathy research and the lessons I have learnt:
Conducting double-blind randomized controlled trials is difficult in any area of medicine. Yet these types of studies are by far the best way to find out which treatments work and which don’t. Therefore, they need doing, regardless of the obstacles they may pose.
In homeopathy, we now have a large body of such trials. Sadly, not all of them are reliable. Those that are, according to accepted criteria, tend to fail to show that homeopathy works better than a placebo. Understandably, homeopaths are disappointed with this overall result and have made numerous attempts to invalidate it.
The main problem with research into homeopathy is not the research methodology. It is well established for clinical trials and can be easily modified to fit all the demands made by individualised treatment or other pecularities that may apply to homeopathy. The main problem is the homeopath who finds it impossible to accept the truth, namely that highly diluted homeopathic remedies are pure placebos and any observed benefits of homeopathy are due to non-specific effects such as the empathetic encounter or a placebo response.
The lesson to be learned from the past is that, in medicine, even the most obsessive belief, conviction or wishful thinking will eventually have to give way to the scientific evidence. In the case of homeopathy, this process has taken an extraordinary amount of time and effort but, finally, we are almost there and the writing is on the wall for everyone to see.
Two resumes of 30 years of work, research and experience!
And what a difference between them!
Who do you think gets closer to the truth,
Jennifer or I?
Of all the forms of so-called alternative medicine (SCAM), Reiki is amongst the least plausible. It is a form of paranormal or ‘energy healing’ popularised by Japanese Mikao Usui (1865–1926). Reiki is based on the assumptions of Traditional Chinese Medicine and the existence of ‘chi’, the life-force that is assumed to determine our health.
Reiki practitioners believe that, with their hands-on healing method, they can transfer ‘healing energy’ to a patient which, in turn, stimulates the self-healing properties of the body. They assume that the therapeutic effects of this technique are obtained from a ‘universal life energy’ that provides strength, harmony, and balance to the body and mind.
Despite its implausibility, Reiki is used for a very wide range of conditions. Some people are even convinced that it has positive effects on sexuality. But is that really so?
This randomised clinical trial was aimed at finding out. Specifically, its authors wanted to determine the effect of Reiki on sexual function and sexual self-confidence in women with sexual distress*. It was was conducted with women between the ages of 15–49 years who were registered at a family health center in the eastern region of Turkey and had sexual distress.
The sample of the study consisted of 106 women, 53 in the experimental group and 53 in the control group. Women in the experimental group received Reiki once a week for four weeks, while no intervention was applied to those in the control group. Data were collected using the Female Sexual Distress Scale-Revised (FSDS-R), the Arizona Sexual Experiences Scale (ASEX), and the Sexual Self-confidence Scale (SSS).
The levels of sexual distress, sexual function, and sexual self-confidence of women in both groups were similar before the intervention, and the difference between the groups was not statistically significant (p > 0.05). After the Reiki application, the FSDS-R and ASEX mean scores of women in the experimental group significantly decreased, while their SSS mean score significantly increased, and the difference between the groups was statistically significant (p < 0.05).
The authors concluded that Reiki was associated with reduced sexual distress, positive outcomes in sexual functions, and increase sexual self-confidence in women with sexual distress. Healthcare professionals may find Reiki to positively enhance women’s sexuality.
Convinced?
I hope not!
The study has the most obvious of all design flaws: it does not control for a placebo effect, nor the effect of empaty/sympathy received from the therapist, nor the negative impact of learning that you are in the control group and will thus not receive any treatment or attention.
To me, it is obvious that these three factors combined must be able to bring about the observed outcomes. Therefore, I suggest to re-write the conclusions as follows:
The intervention was associated with reduced sexual distress, positive outcomes in sexual functions, and increase sexual self-confidence in women with sexual distress. Considering the biological plausibility of a specific effect of Reiki, the most likely cause for the outcome are non-specific effects of the ritual.
*[Sexual distress refers to persistent, recurrent problems with sexual response, desire, orgasm or pain that distress you or strain your relationship with your partner. Yes, I had to look up the definition of that diagnosis.]
Yes, I often moan about the abundance of poor-quality prevalence surveys that we are confronted with when scanning the literaturee on so-called alternative medicine (SCAM), e.g.:
- The survey mania in so-called alternative medicine prevents progress
- A truly homeopathic survey
- A new survey of CAM-use (or is it a promotion for more nonsense on the NHS?)
- A new chiropractic survey seems to avoid all the potentially embarrassing questions
- Survey-mania in alternative medicine: a fruitless, misleading and counter-productive distraction
Here is another example that recently appeared on my screen and that allows me to explain (yet again) why these surveys are such a waste of space:
The Use of Traditional and Complementary Medicine Among Patients With Multiple Sclerosis in Morocco
Let’s assume the survey is done perfectly (a condition that most are very far from meeting). If the information generated by such a perfect survey were worthwhile, we would also need to consider possible mutations that would be just as relevant:
- We have just over 200 nations (other than Morocco) on the planet.
- I assume there are about 1000 conditions (other than multiple sclerosis) for which SCAM is used.
- There are, I estimate, 100 different definitions of SCAM (other than ‘traditional and complementary medicine’) that all include different modalities.
So, this alone would make 20 000 000 surveys that would be important enough to get published. But that’s not all. The usage and nature of SCAM change fairly quickly. That means we would need these 20 million surveys to be repeated every 2 to 3 years to be up-to-date.
For all this, we would need, I estimate, 200 000 research groups doing the work and about 20 000 SCAM journals to publish their results.
I think we can agree that this would be a nonsensical effort for producing millions of papers reaching dramatic conclusions that read something like this:
Our survey shows that patients suffering from xy living in yz use much SCAM. This level of popularity suggests that SCAM is much appreciated and needs to be made available more widely and free of charge.
I rest my case.
I have been called just about everything during my professional life (not to mention the private one). Yesterday, a new addition arrived: a German psychologist who chose to misunderstand a re-Tweet (or is that re-X these days?), Sebastian Bartoschek, implied I am an anti-Semite.
My re-Tweet quoted without any comment by me a Holocaust survivor stating “The Nazis made me afraid to be a Jew, and the Israelis made me ashamed to be a Jew”.
My re-Tweet was meant to make people reflect critical about the horrendous atrocities that is currently happening in Gaza. However, Bartoschek decided it was anti-semitism and demanded I explain myself. As I had previously had an unpleasantly unproductive encounter over an entirely different matter with him, I did not quite see why I should comply to the wishes of this guy. What followed was a rather ridiculous triade by Bartoschek. It included him alerting DIE WELT that someone who sometimes writes for the paper propagates anti-semitism.
A third party (I don’t know who) must have suggested that this amounts to denunciation. Bartoschek replied: “If asking someone why they share anti-Semitic content is denunciation for you, then so be it.” Eventually he sent me this Tweet:
To EdzardErnst – I’ll wait until 11 a.m. tomorrow, Sunday, for a statement. After that, I’ll write about it without it.
This is why I feel that I am blackmailed. Either I explain what I feel is too obvious to explain, or he will write about the matter in what can be expected to be a defaming way.
Well, I prefer to write about it myself by stating categorically that I am definitely not an anti-semite. What is more, I can prove it. I have since many years published numerous articles (around 30, I guess) that make my position entirely clear; to mention just three:
- The most important paper I ever published
- Killing in the name of healing: the active role of the German medical profession during the Third Reich – PubMed (nih.gov)
- Die grauenhaften Verbrechen des Doktor Karl Brandt – Zeit – derStandard.at › Wissenschaft
So, now it will be great fun to see whether Bartoschek has lost his marbles and what version of the truth he will tell in his own write-up of the story.
WATCH THIS SPACE.
Current interventions for posttraumatic stress disorder (PTSD) are efficacious, yet effectiveness may be limited by adverse effects and high withdrawal rates. Acupuncture is an intervention with some positive preliminary but methodologically flawed data for PTSD. Therefore a new study compared verum acupuncture with sham acupuncture (minimal needling) on clinical and physiological outcomes.
This was a 2-arm, parallel-group, prospective blinded randomized clinical trial hypothesizing superiority of verum to sham acupuncture. The study was conducted at a single outpatient-based site, the Tibor Rubin VA Medical Center in Long Beach, California, with recruitment from April 2018 to May 2022, followed by a 15-week treatment period. Following exclusion for characteristics that are known PTSD treatment confounds, might affect biological assessment, indicate past nonadherence or treatment resistance, or indicate risk of harm, 93 treatment-seeking combat veterans with PTSD aged 18 to 55 years were allocated to group by adaptive randomization and 71 participants completed the intervention protocols.
Verum and sham were provided as 1-hour sessions, twice weekly, and participants were given 15 weeks to complete up to 24 sessions. The primary outcome was pretreatment to posttreatment change in PTSD symptom severity on the Clinician-Administered PTSD Scale-5 (CAPS-5). The secondary outcome was pretreatment to posttreatment change in fear-conditioned extinction, assessed by fear-potentiated startle response. Outcomes were assessed at pretreatment, midtreatment, and posttreatment. General linear models comparing within- and between-group were analyzed in both intention-to-treat (ITT) and treatment-completed models.
A total of 85 male and 8 female veterans (mean [SD] age, 39.2 [8.5] years) were randomized. There was a large treatment effect of verum (Cohen d, 1.17), a moderate effect of sham (d, 0.67), and a moderate between-group effect favoring verum (mean [SD] Δ, 7.1 [11.8]; t90 = 2.87, d, 0.63; P = .005) in the intention-to-treat analysis. The effect pattern was similar in the treatment-completed analysis: verum d, 1.53; sham d, 0.86; between-group mean (SD) Δ, 7.4 (11.7); t69 = 2.64; d, 0.63; P = .01). There was a significant pretreatment to posttreatment reduction of fear-potentiated startle during extinction (ie, better fear extinction) in the verum but not the sham group and a significant correlation (r = 0.31) between symptom reduction and fear extinction. Withdrawal rates were low.
The authors concluded that the acupuncture intervention used in this study was clinically efficacious and favorably affected the psychobiology of PTSD in combat veterans. These data build on extant literature and suggest that clinical implementation of acupuncture for PTSD, along with further research about comparative efficacy, durability, and mechanisms of effects, is warranted.
I am not sure that the authors’ enthusiastic verdict is correct. Its lead author was even quoted stating that his study, which used improved controls, was needed to “definitively” support acupuncture for PTSD. He noted that “acupuncture ought to be considered a potential first-line treatment for PTSD.”
While the study is an improvement on the previous research in this area, it is by no means compelling. My main point of criticism is the nature of the sham acupuncture. Such controls are used to account for placebo effects which, of course, can be considerable in the case of acupuncture.
For this concept to work adequately, the patient and the therapist need to be blinded. In the case of acupuncture, therapist blinding is difficult (but not impossible). In this study, therepists were not blinded. Thus they could have influenced the outcome by verbal and non-verbal clues given to the patient. As acupuncturists inevitably have an interest in the positive result of their study, this effect seems inevitable to me.
More important, however, is the adequate blinding of the patient. In this study, it was attempted by using shallow needling as a sham intervention. Yet, shallow needling can easily distinguished from real acupuncture by the patient. At the very least, patients should be asked what treatment – sham or real – they thought they had received. This did not happen, and we therefore might assume that the effect of patient de-blinding – combined with the confounder described above – was sufficient to bring about the relatively small effect sizes observed by the authors.
One might argue that this does not really matter; all that counts is to alleviate the suffering of the patients, never mind by what mechanism. I think, this would be erroneous. It matters because, if acupuncture itself is ineffective (which I suggest), settling for acupuncture as a first line therapy for PTSD is in nobody’s interest and a disservice to severely suffering patients. It would inhibit meaningful research aimed at finding an optimal therapy (one that works beyond placebo) and be a waste of resources.
A recent post of mine started an interesting discussion about the research of the NCCIH. Richard Rasker made the following comment:
The NCCIH was initially established as the Office for Alternative Medicine (OAM) for mostly the same reason that Edzard’s department at Exeter was founded, i.e. to study alternative modalities, and determine once and for all which ones were effective and which ones weren’t. Unfortunately, OAM and its subsequent incarnations were taken over by SCAM proponents almost right away, with its core mission changed into validating (NOT ‘studying’) SCAM modalities – a small but crucial difference that will all but guarantee that even long-obsolete and totally ineffective quackery will continue to be ‘researched’ and promoted.
So what’s the score now, after more than 30 years and well over 4 billion dollars in taxpayers’ money? How many SCAM modalities have they managed to ‘validate’, i.e. definitively proven to be effective? The answer is: none, for all intents and purposes. Even their research into herbal medicine – one of the most effective (or should I say: least ineffective) SCAMs out there – is best described as woefully lacking. Their list of herbs and plants names just 55 species of plants, and the individual descriptions are mostly to the tune of ‘a lot of research was done, but we can’t say anything definite’.
I think I can contribute meaningfully to this important comment and topic. Several years ago, my Exeter team – together with several other researches – systematically reviewed the NCCIH (formerly NCCAM)-sponsored clinical trials. Specifically, we focussed on 4 different subject areas. Here are the conclusions of our articles reporting the findings:
-
-
- ACUPUNCTURE
-
Seven RCTs had a low risk of bias. Numerous methodological shortcomings were identified. Many NCCAM-funded RCTs of acupuncture have important limitations. These findings might improve future studies of acupuncture and could be considered in the ongoing debate regarding NCCAM-funding. [Focus on Alternative and Complementary Therapies Volume 17(1) March 2012 15–21]
2. HERBAL MEDICINE
This independent assessment revealed a plethora of serious concerns related to NCCAM studies of herbal medicine. [Perfusion 2011; 24: 89-102]
3. ENERGY MEDICINE
In conclusion, the NCCAM-funded RCTs of energy medicine are prime examples of misguided investments into research. In our opinion, NCCAM should not be funding poor-quality studies of implausible practices. The impact of any future studies of energy medicine would be negligible or even detrimental. [Focus on Alternative and Complementary Therapies Volume 16(2) June 2011 106–109 ]
4. CHIROPRACTIC
In conclusion, our review demonstrates that several RCTs of chiropractic have been funded by the NCCAM. It raises numerous concerns in relation to these studies; in particular, it suggests that many of these studies are seriously flawed. [https://www.ncbi.nlm.nih.gov/pubmed/21207089]
The overall conclusion that comes to my mind is this:
The NCCIH has managed to spend more money on SCAM research than any other institution in the world (in the 20 years that I ran the Exeter research unit, we spent around £2 million in total). The NCCIH has wasted precious funds on plenty of dubious studies; arguably, this is unethical. It has misappropriated its role from testing to validating SCAMs. And it has validated none.
PS
As some of the above-cited papers are not easily accessible, I offer to send copies to interested individuals on request.
Yesterday, someone (hopefully) unknown to me (hiding under the pseudonym ‘Queristfrei’) tweeted this rather bizarre comment [in German, my translation]:
This trivialisation of the unjust GDR state, in which people died for political reasons, shows how “lost” the people are who @amardeo, @Skepges, @EdzardErnst and the @Skepges respect and defend. That’s historical fabrication to the power of ten! #GWUP
Normally, I would have discarded the comment as just one of those many irrelevant idiocies posted by cranks that I am constantly exposed to on social media. However, the mention of the GWUP, the German skeptics organisation, links it to the current woke-motivated destruction of the GWUP and thus gives it special significance.
‘Woke’ and the various related terms are in fashion and polute discussions on far too many subjects. To be blunt, I don’t like ‘woke, WOKE, anti-woke, unwoke, wokerati’, etc. – so much so that, for the purpose of this post, I will invent an umbrella term that captures all of these words: ANTI-UNWOKERATI, AUWEI for short (yes, there might be a German root in this abbreviation. I know it is a silly acronym but, in my mind, the subject deserves nothing serious).
As already mentioned, I am anti-AUWEI which means I am as much anti-woke as anti-antiwoke. Or, to put it differently, I feel that the world would be a better place, if ‘woke’ had never become en vogue. Here I have listed (in no particular order) several reasons why I dislike AUWEI:
- AUWEI means different things to different people and is thus a fertile basis for misunderstandings.
- Every Tom, Dick and Harry uses the AUWEI terminology pretending to be an expert without expertise.
- Much of what is said and written in the name of AUWEI is pure bullshit.
- AUWEI has become an ideology.
- Even worse, it is a straight jacket of the mind that makes us pre-judge a subject regardless of the evidence.
- Worse still, it is abused by all the wrong politicians.
- AUWEI serves many as a replacement for evidence.
- Even worse, it often seems to be an alternative to critical thinking.
- Most AUWEI-obsessed people seem to have lost their humor (or never had any).
- AUWEI renders complex issues falsely simple.
- AUWEI inhibits free thought.
- AUWEI inhibits nuances and puts you in one camp or another – black or white.
- AUWEI is unnecessarily devisive.
- AUWEI invites intolerance and unproductive dispute.
Personally, I like to make up my own mind about things; to do this, I want to see the evidence. Once I have understood it, I go where the evidence leads me – not where AUWEI dictates me to go.
There are many AUWEI subjects that do not interest me and perhaps even more that I find outright silly. Personally, I don’t want AUWEI to tell me that I must have an opinion on them or quietly follow that of my AUWEI ‘peers’.
No, really; AUWEI is not for me.
The aim of this systematic review and network meta-analysis was to identify the optimal dose and modality of exercise for treating major depressive disorder, compared with psychotherapy, antidepressants, and control conditions.
The screening, data extraction, coding, and risk of bias assessment were performed independently and in duplicate. Bayesian arm based, multilevel network meta-analyses were performed for the primary analyses. Quality of the evidence for each arm was graded using the confidence in network meta-analysis (CINeMA) online tool. All randomised trials with exercise arms for participants meeting clinical cut-offs for major depression were included.
A total of 218 unique studies with a total of 495 arms and 14 170 participants were included. Compared with active controls (eg, usual care, placebo tablet), moderate reductions in depression were found for
- walking or jogging,
- strength training,
- mixed aerobic exercises,
- and tai chi or qigong.
The effects of exercise were proportional to the intensity prescribed. Strength training and yoga appeared to be the most acceptable modalities. Results appeared robust to publication bias, but only one study met the Cochrane criteria for low risk of bias. As a result, confidence in accordance with CINeMA was low for walking or jogging and very low for other treatments.
The authors concluded that exercise is an effective treatment for depression, with walking or jogging, yoga, and strength training more effective than other exercises, particularly when intense. Yoga and strength training were well tolerated compared with other treatments. Exercise appeared equally effective for people with and without comorbidities and with different baseline levels of depression. To mitigate expectancy effects, future studies could aim to blind participants and staff. These forms of exercise could be considered alongside psychotherapy and antidepressants as core treatments for depression.
As far as I can see, there are two main problems with these findings:
- Because too many of the studies are less than rigorous, the results are not quite as certain as the conclusions would seem to imply.
- Patients suffering from a major depressive disorder are often unable (too fatigued, demotivated, etc.) to do and/or keep up vigorous excerise over any length of time.
What I find furthermore puzzling is that, on the one hand, the results show that – as one might expect – the effects are proportional to the intensity of the excercise but, on the other hand tai chi and qugong which are both distinctly low-intensity turn out to be effective.
Nonetheless, this excellent paper is undoubtedly good news and offers hope for patients who are in desperate need of effective, safe and economical treatments.
These days – 11 years after the closure of my department at Exeter – it is not often that I co-author a peer-reviewed paper. All the more reason, I think, to celebrate when it does happen:
Our review was aimed at determining the effectiveness of meditation, primarily mindfulness-based interventions (MBIs) and transcendental meditation (TM), for the primary and secondary prevention of CVD.
We searched CENTRAL, MEDLINE, Embase, three other databases, and two trials registers on 14 November 2021, together with reference checking, citation searching, and contact with study authors to identify additional studies. We included randomised controlled trials (RCTs) of 12 weeks or more in adults at high risk of CVD and those with established CVD. We explored four comparisons: MBIs versus active comparators (alternative interventions); MBIs versus non-active comparators (no intervention, wait list, usual care); TM versus active comparators; TM versus non-active comparators. We used standard Cochrane methods. Our primary outcomes were CVD clinical events (e.g. cardiovascular mortality), blood pressure, measures of psychological distress and well-being, and adverse events. Secondary outcomes included other CVD risk factors (e.g. blood lipid levels), quality of life, and coping abilities. We used GRADE to assess the certainty of evidence.
We included 81 RCTs (6971 participants), with most studies at unclear risk of bias. MBIs versus active comparators (29 RCTs, 2883 participants) Systolic (SBP) and diastolic (DBP) blood pressure were reported in six trials (388 participants) where heterogeneity was considerable (SBP: MD -6.08 mmHg, 95% CI -12.79 to 0.63, I2 = 88%; DBP: MD -5.18 mmHg, 95% CI -10.65 to 0.29, I2 = 91%; both outcomes based on low-certainty evidence). There was little or no effect of MBIs on anxiety (SMD -0.06 units, 95% CI -0.25 to 0.13; I2 = 0%; 9 trials, 438 participants; moderate-certainty evidence), or depression (SMD 0.08 units, 95% CI -0.08 to 0.24; I2 = 0%; 11 trials, 595 participants; moderate-certainty evidence). Perceived stress was reduced with MBIs (SMD -0.24 units, 95% CI -0.45 to -0.03; I2 = 0%; P = 0.03; 6 trials, 357 participants; moderate-certainty evidence). There was little to no effect on well-being (SMD -0.18 units, 95% CI -0.67 to 0.32; 1 trial, 63 participants; low-certainty evidence). There was little to no effect on smoking cessation (RR 1.45, 95% CI 0.78 to 2.68; I2 = 79%; 6 trials, 1087 participants; low-certainty evidence). None of the trials reported CVD clinical events or adverse events. MBIs versus non-active comparators (38 RCTs, 2905 participants) Clinical events were reported in one trial (110 participants), providing very low-certainty evidence (RR 0.94, 95% CI 0.37 to 2.42). SBP and DBP were reduced in nine trials (379 participants) but heterogeneity was substantial (SBP: MD -6.62 mmHg, 95% CI -13.15 to -0.1, I2 = 87%; DBP: MD -3.35 mmHg, 95% CI -5.86 to -0.85, I2 = 61%; both outcomes based on low-certainty evidence). There was low-certainty evidence of reductions in anxiety (SMD -0.78 units, 95% CI -1.09 to -0.41; I2 = 61%; 9 trials, 533 participants; low-certainty evidence), depression (SMD -0.66 units, 95% CI -0.91 to -0.41; I2 = 67%; 15 trials, 912 participants; low-certainty evidence) and perceived stress (SMD -0.59 units, 95% CI -0.89 to -0.29; I2 = 70%; 11 trials, 708 participants; low-certainty evidence) but heterogeneity was substantial. Well-being increased (SMD 0.5 units, 95% CI 0.09 to 0.91; I2 = 47%; 2 trials, 198 participants; moderate-certainty evidence). There was little to no effect on smoking cessation (RR 1.36, 95% CI 0.86 to 2.13; I2 = 0%; 2 trials, 453 participants; low-certainty evidence). One small study (18 participants) reported two adverse events in the MBI group, which were not regarded as serious by the study investigators (RR 5.0, 95% CI 0.27 to 91.52; low-certainty evidence). No subgroup effects were seen for SBP, DBP, anxiety, depression, or perceived stress by primary and secondary prevention. TM versus active comparators (8 RCTs, 830 participants) Clinical events were reported in one trial (201 participants) based on low-certainty evidence (RR 0.91, 95% CI 0.56 to 1.49). SBP was reduced (MD -2.33 mmHg, 95% CI -3.99 to -0.68; I2 = 2%; 8 trials, 774 participants; moderate-certainty evidence), with an uncertain effect on DBP (MD -1.15 mmHg, 95% CI -2.85 to 0.55; I2 = 53%; low-certainty evidence). There was little or no effect on anxiety (SMD 0.06 units, 95% CI -0.22 to 0.33; I2 = 0%; 3 trials, 200 participants; low-certainty evidence), depression (SMD -0.12 units, 95% CI -0.31 to 0.07; I2 = 0%; 5 trials, 421 participants; moderate-certainty evidence), or perceived stress (SMD 0.04 units, 95% CI -0.49 to 0.57; I2 = 70%; 3 trials, 194 participants; very low-certainty evidence). None of the trials reported adverse events or smoking rates. No subgroup effects were seen for SBP or DBP by primary and secondary prevention. TM versus non-active comparators (2 RCTs, 186 participants) Two trials (139 participants) reported blood pressure, where reductions were seen in SBP (MD -6.34 mmHg, 95% CI -9.86 to -2.81; I2 = 0%; low-certainty evidence) and DBP (MD -5.13 mmHg, 95% CI -9.07 to -1.19; I2 = 18%; very low-certainty evidence). One trial (112 participants) reported anxiety and depression and found reductions in both (anxiety SMD -0.71 units, 95% CI -1.09 to -0.32; depression SMD -0.48 units, 95% CI -0.86 to -0.11; low-certainty evidence). None of the trials reported CVD clinical events, adverse events, or smoking rates.
We concluded that despite the large number of studies included in the review, heterogeneity was substantial for many of the outcomes, which reduced the certainty of our findings. We attempted to address this by presenting four main comparisons of MBIs or TM versus active or inactive comparators, and by subgroup analyses according to primary or secondary prevention, where there were sufficient studies. The majority of studies were small and there was unclear risk of bias for most domains. Overall, we found very little information on the effects of meditation on CVD clinical endpoints, and limited information on blood pressure and psychological outcomes, for people at risk of or with established CVD. This is a very active area of research as shown by the large number of ongoing studies, with some having been completed at the time of writing this review. The status of all ongoing studies will be formally assessed and incorporated in further updates.
Some people will say that meditation is not a form of so-called alternative medicine (SCAM) but rather an aspect of lifestyle used for relaxation and well-being. As such, it should not be scrutinized like a therapy. This might be partly true, but as soon as proper health claims are made for meditation or similar modalities, they do need to be tested like any other therapy, in my view.
As our review demonstrates, meditation and similar treatments are not nearly as well supported by evidence as their proponents try to make us believe. In other words, the often-voiced claims that such therapies are effective for the primary and secondary prevention of cardiovascular disease are largely unfounded.
