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.
Getting old is not nice – but think of the alternative!
I think it was Woody Allen who said something to that extent. But there is a third way, at least this is waht Tai Chi advocates want us to believe.
Utilizing a hybrid design, this study aimed to test whether both long-term and short-term Tai Chi (TC) training are associated with age-related decline in physical function in healthy older adults.
The authors first conducted cross-sectional comparisons among TC-naïve older adults (n = 60, 64.2 ± 7.7 years), TC-expert older adults (n = 27, 62.8 ± 7.6 years, 24.5 ± 12 years experience), and TC-naïve younger adults (n = 15, 28.7 ± 3.2 years) to inform long-term effects of TC training on physical function, including single leg stance time with eyes closed, grip strength, Timed Up and Go, maximum walking speed, functional reach, and vertical jump for lower-extremity power. There were significant differences among the three groups on all the six tests. For most functional tests, TC-experts performed better than age-matched TC-naïve controls and were statistically indistinguishable from young healthy adult controls. Long-term TC training was associated with higher levels of physical function in older adults, suggesting a potential preventative healthy aging effect.
In the randomized longitudinal trial, TC-naïve subjects were randomized (n = 31 to Tai Chi group, n = 29 to usual care control group) to evaluate the short-term effects of TC over 6 months on all outcomes. TC’s short-term impacts on physical function were small and not statistically significant. The impact of short-term training in healthy adults is less clear.
The authors concluded that both potential longer-term preventive effects and shorter-term restorative effects warrant further research with rigorous, adequately powered controlled clinical trials.
Even though the authors imply that their cross-sectional comparison points to a causal effect, this is clearly not true. For instance, it could easily be that people who are somehow destined to keep fit and agile are the ones who keep up Tai Chi. So, rather than being the result of Tai Chi, the proneness to fitness and agility could be the cause for doing Tai Chi.
The authors laudably were aware of these problems and therefore also did an RCT. Sadly this RCT did not yield significant findings. Essentially this means that eitherTai Chi did not work, or the study was naively inadequate, e.g. too small and too short-term.
Thus the authors finish with the usual statement that MORE RESEARCH IS NEEDED. This might be true, but is a definitive RCT likely?
I don’t think so.
A long time ago I had designed such a definitive study. It needed to be very large considering that many participants might drop out. Crucially, it also had to be long- term, i.e. years, not months.
And what happened to my study?
I never managed to get it funded, mainly because the costs would have been astronomical.
This systematic review aimed to assess the impact of Tai Chi on individuals with essential hypertension and to compare the effects of Tai Chi with other therapies. The researchers conducted a systematic literature search of the Medline, Scholar, Elsevier, Wiley Online Library, Chinese Academic Journal (CNKI) and Wanfang databases from January 2003 to August 2023. Using the methods of the Cochrane Collaboration Handbook, a meta-analysis was conducted to assess the collective impact of Tai Chi exercise in controlling hypertension. The primary outcomes measured included blood pressure and nitric oxide levels.
A total of 32 RCTs were included. The participants consisted of adults with an average age of 57.1 years who had hypertension (mean ± standard deviation systolic blood pressure at 148.2 ± 12.1 mmHg and diastolic blood pressure at 89.2 ± 8.3 mmHg). Individuals who practiced Tai Chi experienced reductions in systolic blood pressure of 10.6 mmHg, diastolic blood pressure of 4.7 mmHg and an increase in nitric oxide levels.
The authors concluded that Tai Chi can be a viable lifestyle intervention for managing hypertension. Greater promotion of Tai Chi by medical professionals could extend these benefits to a larger patient population.
Tai Chi allegedly incorporates principles rooted in the Yin and Yang theory, Chinese medicine meridians and breathing techniques, and creates a unique form of exercise characterized by its inward focus, continuous flow, the balance of strength and gentleness, and alternation between fast and slow movements. What sets Tai Chi apart from other forms of excercise is the requirement for mindful guidance during practice. This aspect may, according to the authors, be the reason why Tai Chi also outperforms general aerobic exercise in managing hypertension.
I can well imagine that any form of relaxation reduces blood pressure. What I find hard to believe is that Tai Chi is better than any other relaxing SCAMs. The 32 RCTs included in this new review fail to impress me because they are all from China, and – as we have often mentioned before – studies from China are to be taken with a pinch of salt.
Yet, the subject is important enough, in my view, to merit a few rigorous trials conducted by independent researchers. Until such data are available, I think, I prefer to rely on our own systematic review which conculded that the evidence for tai chi in reducing blood pressure … is limited. Whether tai chi has benefits over exercise is still unclear. The number of trials and the total sample size are too small to draw any firm conclusions.
The American Heart Association has issued a statement outlining research on so-called alternative medicine (SCAM) for heart failure. They found some SCAMs that work, some that don’t work, and some that are harmful.
Alternative therapies that may benefit people with heart failure include:
- Omega-3 polyunsaturated fatty acids (PUFA, fish oil) have the strongest evidence among complementary and alternative agents for clinical benefit in people with heart failure and may be used safely, in moderation, in consultation with their health care team. Omega-3 PUFA is associated with a lower risk of developing heart failure and, for those who already have heart failure, improvements in the heart’s pumping ability. There appears to be a dose-related increase in atrial fibrillation (an irregular heart rhythm), so doses of 4 grams or more should be avoided.
- Yoga and Tai Chi, in addition to standard treatment, may help improve exercise tolerance and quality of life and decrease blood pressure.
Meanwhile, some therapies were found to have harmful effects, such as interactions with common heart failure medications and changes in heart contraction, blood pressure, electrolytes and fluid levels:
- While low blood levels of vitamin D are associated with worse heart failure outcomes, supplementation hasn’t shown benefit and may be harmful when taken with heart failure medications such as digoxin, calcium channel blockers and diuretics.
- The herbal supplement blue cohosh, from the root of a flowering plant found in hardwood forests, might cause a fast heart rate called tachycardia, high blood pressure, chest pain and may increase blood glucose. It may also decrease the effect of medications taken to treat high blood pressure and Type 2 diabetes.
- Lily of the valley, the root, stems and flower of which are used in supplements, has long been used in mild heart failure because it contains active chemicals similar to, but less potent than, the heart failure medicine digoxin. It may be harmful when taken with digoxin by causing very low potassium levels, a condition known as hypokalemia. Lily of the valley also may cause irregular heartbeat, confusion and tiredness.
Other therapies have been shown as ineffective based on current data, or have mixed findings, highlighting the importance of patients having a discussion with a health care professional about any non-prescribed treatments:
- Routine thiamine supplementation isn’t shown to be effective for heart failure treatment unless someone has this specific nutrient deficiency.
- Research on alcohol varies, with some data showing that drinking low-to-moderate amounts (1 to 2 drinks per day) is associated with preventing heart failure, while habitual drinking or intake of higher amounts is toxic to the heart muscle and known to contribute to heart failure.
- There are mixed findings about vitamin E. It may have some benefit in reducing the risk of heart failure with preserved ejection fraction, a type of heart failure in which the left ventricle is unable to properly fill with blood between heartbeats. However, it has also been associated with an increased risk of hospitalization in people with heart failure.
- Co-Q10, or coenzyme Q10, is an antioxidant found in small amounts in organ meats, oily fish and soybean oil, and commonly taken as a dietary supplement. Small studies show it may help improve heart failure class, symptoms and quality of life, however, it may interact with blood pressure lowering and anti-clotting medicines. Larger trials are needed to better understand its effects.
- Hawthorn, a flowering shrub, has been shown in some studies to increase exercise tolerance and improve heart failure symptoms such as fatigue. Yet it also has the potential to worsen heart failure, and there is conflicting research about whether it interacts with digoxin.
“Overall, more quality research and well-powered randomized controlled trials are needed to better understand the risks and benefits of complementary and alternative medicine therapies for people with heart failure,” said Chow. “This scientific statement provides critical information to health care professionals who treat people with heart failure and may be used as a resource for consumers about the potential benefit and harm associated with complementary and alternative medicine products.”
No doubt, this assessment is a laudable attempt to inform patients responsibly. Personally, I am always a bit skeptical about such broad statements. SCAM encompasses some 400 different therapies, and I doubt that these can all be assessed in one single overview.
It is not difficult to find SCAMs that seem to have not been considered. Take this systematic review, for instance. It included 24 RCTs (n = 1314 participants) of 9 different mind-body interventions (MBI) types: Tai Chi (n = 7), yoga (n = 4), relaxation (n = 4), meditation (n = 2), acupuncture (n = 2), biofeedback (n = 2), stress management (n = 1), Pilates (n = 1), and reflexology (n = 1). Most (n = 22, 95.8%) reported small-to-moderate improvements in quality of life (14/14 studies), exercise capacity (8/9 studies), depression (5/5 studies), anxiety and fatigue (4/4 studies), blood pressure (3/5 studies), heart rate (5/6 studies), heart rate variability (7/9 studies), and B-type natriuretic peptide (3/4 studies). Studies ranged from 4 minutes to 26 weeks and group sizes ranged from 8 to 65 patients per study arm.
The authors concluded that, although wide variability exists in the types and delivery, RCTs of MBIs have demonstrated small-to-moderate positive effects on HF patients’ objective and subjective outcomes. Future research should examine the mechanisms by which different MBIs exert their effects.
Or take this systematic review of 38 RCTs of oral TCM remedies. The majority of the included trials were assessed to be of high clinical heterogeneity and poor methodological quality. The main results of the meta-analysis showed improvement in total MLHFQ score when oral Chinese herbal medicine plus conventional medical treatment (CMT) compared with CMT with or without placebo [MD = -5.71 (-7.07, -4.36), p < 0.01].
The authors concluded that there is some encouraging evidence of oral Chinese herbal medicine combined with CMT for the improvement of QoL in CHF patients. However, the evidence remains weak due to the small sample size, high clinical heterogeneity, and poor methodological quality of the included trials. Further, large sample size and well-designed trials are needed.
Don’t get me wrong: I am not saying that TCM remedies are a viable option – in fact, I very much doubt it – but I am saying that attempts to provide comprehensive overviews of all SCAMs are problematic, and that incomplete overviews are just that: incomplete.
Tai chi is a meditative exercise therapy based on Traditional Chinese Medicine. On this blog, we have repeatedly discussed this so-called alternative medicine (SCAM). It involves meditative movements rooted in both Traditional Chinese Medicine and the martial arts. Tai chi was originally aimed at enhancing mental and physical health; today it has become a popular alternative therapy.
This systematic review assessed the efficiency of tai chi (TC) in different populations’ cognitive function improvement. Randomized controlled trials (RCTs) published from the beginning of coverage through October 17, 2020 in English and Chinese were retrieved from many indexing databases. Selected studies were graded according to the Cochrane Handbook for Systematic Reviews of Intervention 5.1.0. The outcome measures of cognitive function due to traditional TC intervention were obtained. Meta-analysis was conducted by using RevMan 5.4 software. We follow the PRISMA 2020 guidelines.
Thirty-three RCTs, with a total of 1808 participants, were included. The results showed that TC can progress global cognition when assessed in middle-aged as well as elderly patients suffering from cognitive and executive function impairment. The findings are as follows:
- Montreal Cognitive Assessment Scale: mean difference (MD) = 3.23, 95% CI = 1.88-4.58, p < 0.00001,
- Mini-Mental State Exam: MD = 3.69, 95% CI = 0.31-7.08, p = 0.03,
- Trail Making Test-Part B: MD = -13.69, 95% CI = -21.64 to -5.74, p = 0.0007.
The memory function of older adults assessed by the Wechsler Memory Scale was as follows: MD = 23.32, 95% CI = 17.93-28.71, p < 0.00001. The executive function of college students evaluated by E-prime software through the Flanker test was as follows: MD = -16.32, 95% CI = -22.71 to -9.94, p < 0.00001.
The authors concluded that TC might have a positive effect on the improvement of cognitive function in middle-aged and elderly people with cognitive impairment as well as older adults and college students.
These days, I easily get irritated with such conclusions. That TC might improve cognitive function is obvious. If not, there would be no reason to do a review! But does it?
This paper does not provide an answer. All it shows is that TC trials are of lousy quality and that the observed effects might well be due not to TC itself by to non-specific effects.
This overview was aimed at critically appraising the best available systematic review (SR) evidence on the health
effects of Tai Chi. Nine databases (English and Chinese languages) were searched for SRs of controlled clinical trials of Tai Chi interventions published between Jan-2010 and Dec-2020 in any language. Excluded were primary studies and meta-analyses that combined Tai Chi with other interventions. To minimize overlap, effect estimates were extracted from the most recent, comprehensive, highest quality SR for each population, condition, and outcome. SR quality was appraised using AMSTAR 2 and effect estimates with GRADE.
Of the 210 included SRs, 193 only included randomized controlled trials, one only included non-randomized
studies of interventions, and 16 included both. The most common conditions were neurological (18.6%), falls/balance (14.7%), cardiovascular (14.7%), musculoskeletal (11.0%), cancer (7.1%) and diabetes mellitus (6.7%). Except for stroke, no evidence for disease prevention was found, instead, proxy-outcomes/risks factors were evaluated. 114 effect estimates were extracted from 37 SRs (2 high quality, 6 moderate, 18 low, and 11 critically low), representing 59,306 adults. Compared to active and/or inactive controls, a clinically important benefit from Tai Chi was reported for 66 effect estimates; 53 reported an equivalent or marginal benefit, and 6 had an equivalent risk of adverse events. Eight effect estimates (7.0%) were graded as high certainty evidence, 43 (37.7%) moderate, 36 (31.6%) low, and 27 (23.7%) very low. This was due to concerns with risk of bias in 92 (80.7%) effect estimates, imprecision in 43 (37.7%), inconsistency in 37 (32.5%), and publication bias in 3 (2.6%). SR quality was limited by the search strategies, language bias, inadequate consideration of clinical, methodological, and statistical heterogeneity, poor reporting standards, and/or no registered protocol.
The authors concluded that the findings suggest Tai Chi has multisystem effects with physical, psychological, and quality of life benefits for a wide range of conditions, including individuals with multiple health problems. Clinically important benefits were most consistently reported for Parkinson’s disease, falls risk, knee osteoarthritis, low back pain, cardiovascular diseases including hypertension, and stroke. Notwithstanding, for most conditions, higher quality primary studies and SRs are required.
The authors start the discussion section by stating: This critical overview comprehensively identified SRs of Tai Chi published in English, Chinese and Korean languages that evaluated the effectiveness and safety of Tai Chi for health promotion, and disease prevention and management.
I must say that I do not find the overview all that ,critical’. The authors admit that the primary studies often lacked scientific rigor. Yet they draw firm positive conclusions from the data. I think that this is wrong.
Most of the authors of this overview come from Chinese institutions dedicated to promoting TCM. Yet there is no declaration that this fact might constitute a conflict of interest.
I also miss critical comments on two important questions:
- Are the positive effects of Tai chi superior to conventional treatments of the respective conditions?
- Are the effects of Tai chi really due to the treatment per see or might they be largely caused by context effects (which, considering the nature of the therapy, might be substantial)?
Tai chi is a form of exercise that combines deep breathing and relaxation with meditative, slow movements. Originally developed as a martial art in 13th-century China, tai chi is now practised around the world as a health-promoting exercise. Despite its popularity, its therapeutic value is not clear.
This randomized, assessor-blinded trial examined the therapeutic efficacy of tai chi for the management of central obesity. A total of 543 participants with central obesity were randomly assigned in a 1:1:1 ratio to:
- a control group with no exercise intervention (n = 181),
- conventional exercise consisting of aerobic exercise and strength training (EX group) (n = 181),
- a tai chi group (TC group) (n = 181). Interventions lasted 12 weeks.
Outcomes were assessed at baseline, week 12, and week 38. The primary outcome was waist circumference (WC). Secondary outcomes were body weight; body mass index; high-density lipoprotein cholesterol (HDL-C), triglyceride, and fasting plasma glucose levels; blood pressure; and incidence of remission of central obesity.
The adjusted mean difference in WC from baseline to week 12 in the control group was 0.8 cm (95% CI, -4.1 to 5.7 cm). Both intervention groups showed reductions in WC relative to control (adjusted mean differences: TC group vs. control, -1.8 cm [CI, -2.3 to -1.4 cm]; P < 0.001; EX group vs. control: -1.3 cm [CI, -1.8 to -0.9 cm]; P < 0.001); both intervention groups also showed reductions in body weight (P < 0.05) and attenuation of the decrease in HDL-C level relative to the control group. The favorable changes in WC and body weight were maintained in both the TC and EX groups, whereas the beneficial effect on HDL-C was only maintained in the TC group at week 38.
The authors concluded that Tai chi is an effective approach to reduce WC in adults with central obesity aged 50 years or older.
This is a decent trial with an odd conclusion: it is not just the Tai chi intervention but both types of exercise that yield significantly positive effects on the primary outcome measure. So, why did the authors not conclude exercise is an effective approach to reduce WC in adults with central obesity aged 50 years or older?
Could it be that such a conclusion would have meant stating the obvious?
Traditional Chinese Medicine (TCM) is a term created by Mao lumping together various modalities in an attempt to pretend that healthcare in the People’s Republic of China (PRC) was being provided despite the most severe shortages of conventional doctors, drugs and facilities. Since then, TCM seems to have conquered the West, and, in the PRC, the supply of conventional medicine has hugely increased. Today therefore, TCM and conventional medicine peacefully co-exist side by side in the PRC on an equal footing.
At least this is what we are being told – but is it true?
I have visited the PRC twice. The first time, in 1980, I was the doctor of a university football team playing several games in the PRC, including one against their national team. The second time, in 1991, I co-chaired a scientific meeting in Shanghai. On both occasions, I was invited to visit TCM facilities and discuss with colleagues issues related to TCM in the PRC. All the official discussions were monitored by official ‘minders’, and therefore fee speech and an uninhibited exchange of ideas are not truly how I would describe them. Yet, on both visits, there were occasions when the ‘minders’ were absent and a more liberal discussion could ensue. Whenever this was the case, I did not at all get the impression that TCM and conventional medicine were peacefully co-existing. The impression that I did get was that their co-existence resembled more a ‘shot-gun marriage’.
During my time running the SCAM research unit at Exeter, I had the opportunity to welcome several visiting researchers from the PRC. This experience seemed to confirm my impression that TCM in the PRC was less than free. As an example, I might cite one acupuncture project I was once working on with a scientist from the PRC. When it was nearing its conclusion and I mentioned that we should now think about writing it up to publish the findings, my Chinese colleague said that being a co-author was unfortunately not an option. Knowing how important publications in Western journals are for researchers from the PRC, I was most surprised by this revelation. The reason, it turned out, was that our findings failed to be favourable for TCM. My friend explained that such a paper would not advance but hinder an academic career, once back in the PRC.
Suspecting that the notion of a peaceful co-existence of TCM and conventional medicine in the PRC was far from true, I have always been puzzled how the myth could survive for so many years. Now, finally, it seems to crumble. This is from a recent journalistic article entitled ‘Chinese Activists Protest the Use of Traditional Treatments – They Want Medical Science’ which states that thousands of science activists in the PRC protest that the state neglects its duty to treat its citizens with evidence-based medicine (here is the scientific article this is based on):
Over a number of years, Chinese researcher Qiaoyan Zhu, who has been affiliated with the University of Copenhagen’s Department of Communication, has collected data on the many thousand science activists in China through observations in Internet forums, on social media and during physical meetings. She has also interviewed hundreds of activists. Together with Professor Maja Horst, who has specialized in research communication, she has analyzed the many data on the activists and their protests in an article that has just been published in the journal Public Understanding of Science:
“The activists are better educated and wealthier than the average Chinese population, and a large majority of them keep up-to-date with scientific developments. The protests do not reflect a broad popular movement, but the activists make an impact with their communication at several different levels,” Maja Horst explained and added: “Many of them are protesting individually by writing directly to family, friends and colleagues who have been treated with – and in some cases taken ill from – Traditional Chinese Medicine. Some have also hung posters in hospitals and other official institutions to draw attention to the dangers of traditional treatments. But most of the activism takes place online, on social media and blogs.
Activists operating in a regime like the Chinese are obviously not given the same leeway as activists in an open democratic society — there are limits to what the authorities are willing to accept in the public sphere in particular. However, there is still ample opportunity to organize and plan actions online.
“In addition to smaller groups and individual activists that have profiles on social media, larger online groups are also being formed, in some cases gaining a high degree of visibility. The card game with 52 criticisms about Traditional Chinese Medicine that a group of activists produced in 37,000 copies and distributed to family, friends and local poker clubs is a good example. Poker is a highly popular pastime in rural China so the critical deck of cards is a creative way of reaching a large audience,” Maja Horst said.
Maja Horst and Qiaoyan Zhu have also found examples of more direct action methods, where local activist groups contact school authorities to complain that traditional Chinese medicine is part of the syllabus in schools. Or that activists help patients refuse treatment if they are offered treatment with Traditional Chinese Medicine.
I am relieved to see that, even in a system like the PRC, sound science and compelling evidence cannot be suppressed forever. It has taken a mighty long time, and the process may only be in its infancy. But there is hope – perhaps even hope that the TCM enthusiasts outside the PRC might realise that much of what came out of China has led them up the garden path!?
Alternative practitioners practise highly diverse therapies. They seem to have nothing in common – except perhaps that ALL of them are allegedly stimulating our self-healing powers (and except that most proponents are latently or openly against vaccinations). And it is through these self-healing powers that the treatments in question cure anything and become a true panacea. When questioned what these incredible powers really are, most practitioners would (somewhat vaguely) name the immune system as the responsible mechanism. With this post, I intend to provide a short summary of the evidence on this issue:
Acupuncture: no good evidence to show stimulation of self-healing powers.
Aromatherapy: no good evidence to show stimulation of self-healing powers.
Bioresonance: no good evidence to show stimulation of self-healing powers.
Chiropractic: no good evidence to show stimulation of self-healing powers.
Detox: no good evidence to show stimulation of self-healing powers.
Energy healing: no good evidence to show stimulation of self-healing powers.
Feldenkrais: no good evidence to show stimulation of self-healing powers.
Gua sha: no good evidence to show stimulation of self-healing powers.
Herbal medicine: no good evidence to show stimulation of self-healing powers.
Homeopathy: no good evidence to show stimulation of self-healing powers.
Macrobiotics: no good evidence to show stimulation of self-healing powers.
Naturopathy: no good evidence to show stimulation of self-healing powers.
Osteopathy: no good evidence to show stimulation of self-healing powers.
Power bands: no good evidence to show stimulation of self-healing powers.
Reiki: no good evidence to show stimulation of self-healing powers.
Reflexology: no good evidence to show stimulation of self-healing powers.
Shiatsu: no good evidence to show stimulation of self-healing powers.
Tai chi: no good evidence to show stimulation of self-healing powers.
TCM: no good evidence to show stimulation of self-healing powers.
Vibrational therapy: no good evidence to show stimulation of self-healing powers.
Vaccinations: very good evidence to show stimulation of self-healing powers.
As I have stated repeatedly, I am constantly on the look-out for positive news about alternative medicine. Usually, I find plenty – but when I scrutinise it, it tends to crumble in the type of misleading report that I often write about on this blog. Truly good research in alternative medicine is hard to find, and results that are based on rigorous science and show a positive finding are a bit like gold-dust.
But hold on, today I have something!
This systematic review was aimed at determining whether physical exercise is effective in improving cognitive function in the over 50s. The authors evaluated all randomised controlled trials of physical exercise interventions in community-dwelling adults older than 50 years with an outcome measure of cognitive function.
39 studies were included in the systematic review. Analysis of 333 dependent effect sizes from 36 studies showed that physical exercise improved cognitive function. Interventions of aerobic exercise, resistance training, multicomponent training and tai chi, all had significant point estimates. When exercise prescription was examined, a duration of 45–60 min per session and at least moderate intensity, were associated with benefits to cognition. The results of the meta-analysis were consistent and independent of the cognitive domain tested or the cognitive status of the participants.
The authors concluded that physical exercise improved cognitive function in the over 50s, regardless of the cognitive status of participants. To improve cognitive function, this meta-analysis provides clinicians with evidence to recommend that patients obtain both aerobic and resistance exercise of at least moderate intensity on as many days of the week as feasible, in line with current exercise guidelines.
But this is not alternative medicine, I hear you say.
You are right, mostly, it isn’t. There were a few RCTs of tai chi and yoga, but the majority was of conventional exercise. Moreover, most of these ‘alternative’ RCTs were less convincing than the conventional RCTs; here is one of the former category:
Community-dwelling older adults (N = 118; mean age = 62.0) were randomized to one of two groups: a Hatha yoga intervention or a stretching-strengthening control. Both groups participated in hour-long exercise classes 3×/week over the 8-week study period. All participants completed established tests of executive function including the task switching paradigm, n-back and running memory span at baseline and follow-up. Analysis of covariances showed significantly shorter reaction times on the mixed and repeat task switching trials (partial η(2) = .04, p < .05) for the Hatha yoga group. Higher accuracy was recorded on the single trials (partial η(2) = .05, p < .05), the 2-back condition of the n-back (partial η(2) = .08, p < .001), and partial recall scores (partial η(2) = .06, p < .01) of running span task.
I just wanted to be generous and felt the need to report a positive result. I guess, this just shows how devoid of rigorous research generating a positive finding alternative medicine really is.
Of course, there are many readers of this blog who are convinced that their pet therapy is supported by excellent evidence. For them, I have this challenge: if you think you have good evidence for an alternative therapy, show it to me (send it to me via the ‘contact’ option of this blog or post the link as a comment below). Please note that any evidence I would consider analysing in some detail (writing a full blog post about it) would need to be recent, peer-reviewed and rigorous.