If a lie is repeated often, it is said, people will eventually believe it. It is also said that people with simple thinking more readily believe bigger lies. Small lies, interspersed here and there, in speeches, lectures, sermons, media bytes, news reports, columns, research papers, can coalesce into a big lie. If the state and the media keep suppressing the truth, that big lie then perpetuates and stays. This is precisely the case with modern day yoga. Lies, small ones here and there, crafted carefully and sprinkled gently, have now grown into such a big lie that any one hardly questions it.

How ironical indeed! The very first limb or step of Ashtanga Yoga, codified in the much trumpeted Yoga Sutras of Patanjali, is Yama (vows). Satya or truthfulness is the second of the five vows. But that TRUTH is the biggest casualty in the modern fanfare around yoga.

These statements are from two articles published in the Journal of Association of Physicians of India:

The science of yoga is an ancient one. It is a rich heritage of our culture. Several older books make a mention of the usefulness of yoga in the treatment of certain diseases and preservation of health in normal individuals. …Apart from its spiritual philosophy, yoga has been utilized as a therapeutic tool to achieve positive health…[Sahay BK, 2000]

Yoga has been applied in the field of therapeutics in modern times. Yoga has given the patient hope to reduce medication and slow the progress of disease.[Singh S, 2004]

No references have been cited in the articles for these statements.

But the facts are to the contrary:

The oldest and greatest contribution to the world from India – it is not.

The greatest contribution from Hinduism – it is not.

Way of life – it is not.

Has helped Indians with health and vitality for millennia – no

Helps to treat and cure all ailments, even the ones that cannot be cured by modern medicine – not at all.

I had written in January 2009 [Do We Need Yoga] about the available evidence for the efficacy of yoga in treating human diseases. On the occasion of International Yoga Day, let’s revisit the same and look at fresh evidence, if any.

All the available evidence as of now, and the systematic reviews and meta-analyses, indicate clearly that YOGA DOES NOT CURE or PREVENT, or significantly alleviate, ANY ailment, that affects humans. Read EVERY SECTION BELOW, CAREFULLY, BETWEEN THE LINES. It will be clear that even the most sympathetic voices for yoga DO NOT endorse it as a stand-alone treatment for any human illness.

The Origins of the Great Lie:

Yoga was never a part of Indian systems of medicine. Indian medical texts such as Charaka Samhita or Ashtanga Hrudaya do not mention yoga as a method of prevention or treatment of any disease.

The credit for entwining the so called yoga with health and fitness must go to Manibhai Haribhai Desai, also known as Shri Yogendra (1897-1989), and Jagannath Ganesh Gune, also known as Swami Kuvalayananda (1883-1966). Both these were students of Paramahamsa Shree Madhavadasji Maharaj of Malsar, Gujarat. While Shri Yogendra established the Yoga Institute at Santa Cruz, Bombay in 1918, Kuvalayananda founded the Kaivalyadhama at Lonavla in 1924. Both these centres initiated the studies on yoga and health, and since then, many other institutions, in India and abroad, have conducted thousands of such studies, many of them small, and some randomised and controlled. Since 1935 the Kaivalyadhama has published most of its research in its own publication, the Yoga-Mimamsa journal. Several other journals, mainly those devoted to complimentary and alternative medicine, and a few mainstream medical journals, have also published papers on studies related to yoga. Now a PubMed search for yoga returns more than 3000 citations.

Yet, after 100 years of studies that churned out more than 3000 papers, the proponents of ‘yoga therapy have failed to find any conclusive evidence for the efficacy of yoga in treating any illness. They have not even been successful in standardizing the so called yoga therapy.

According to Verrastro [Verrastro G, 2014], although yoga has been deemed effective for treating conditions from hypertension to epilepsy, many claims are poorly substantiated. Most of these studies are small, short, uncontrolled, non-blinded, with many methodological flaws and high risk of bias. And in most of the studies, details of adverse events and injuries are also not mentioned. Moreover, yoga practices used in the interventions vary markedly, making comparison of results difficult. Interventions have ranged from a single 1-hour session to weekly sessions over several months to inpatient treatment that included many lifestyle modifications. Some studies required subjects to practice physically demanding asanas, while others focused on pranayama or practices similar to guided relaxation.[Verrastro G, 2014]

A bibliometric analysis of the characteristics of randomized controlled trials (RCTs) of yoga [Cramer H et al, BMC CAM, 2014] included a total of 366 papers published over forty years, between 1975 and 2014, reporting 312 RCTs from 23 different countries with 22,548 participants. The analysis found that most trials were relatively small in size and failed to explore even common medical conditions frequently. More than 40 different yoga styles were used in the analyzed RCTs; whilst most trials included yoga postures and breathing, yoga meditation and philosophy were less often used (that means, not much of “yoga”). The median study sample size was 59 (range 8–410). Two hundred sixty-four RCTs (84.6%) were conducted with adults, 105 (33.7%) with older adults and 31 (9.9%) with children. Eighty-four RCTs (26.9%) were conducted with healthy participants. Other trials enrolled patients with one of 63 varied medical conditions; the most common being breast cancer (17 RCTs, 5.4%), depression (14 RCTs, 4.5%), asthma (14 RCTs, 4.5%) and type 2 diabetes mellitus (13 RCTs, 4.2%). Whilst 119 RCTs (38.1%) did not define the style of yoga used, 35 RCTs (11.2%) used Hatha yoga and 30 RCTs (9.6%) yoga breathing. The remaining 128 RCTs (41.0%) used 46 varied yoga styles, with a median intervention length of 9 weeks (range 1 day to 1 year). Two hundred and forty-four RCTs (78.2%) used yoga postures, 232 RCTs (74.4%) used breath control, 153 RCTs (49.0%) used meditation and 32 RCTs (10.3%) used philosophy lectures. One hundred and seventy-four RCTs (55.6%) compared yoga with no specific treatment; 21 varied control interventions were used in the remaining RCTs. The authors of this analysis concluded that the available research evidence is sparse for most conditions, and more research is clearly needed. Besides primary research, up-to-date systematic reviews and meta-analyses are needed at least for the most commonly studied conditions in order to evaluate the level of evidence and strength of recommendation for or against the use of yoga in each condition.[Cramer H et al, BMC CAM, 2014]

Some systematic reviews and meta analysis, including the Cochrane reviews, of the studies on yoga are also now available. But none of them provide any conclusive evidence for the efficacy of yoga in the treatment of any human illness, mental or physical.

A systematic review of published research on meditation, done by the University of Alberta Evidence-based Practice Center, requested and funded by the National Center for Complementary and Alternative Medicine (NCCAM) and published in June 2007, found the body of evidence to be inadequate to arrive at any conclusions. [Ospina MB, 2007] The review identified five broad categories of meditation practices (Mantra meditation, Mindfulness meditation, Yoga, Tai Chi, and QiGong). Characterization of the universal or supplemental components of meditation practices was precluded by the theoretical and terminological heterogeneity among practices. Evidence on the state of research in meditation practices was provided in 813 predominantly poor-quality studies. The three most studied conditions were hypertension, other cardiovascular diseases, and substance abuse. The review concluded that many uncertainties surround the practice of meditation, scientific research on meditation practices does not appear to have a common theoretical perspective and is characterized by poor methodological quality and, therefore firm conclusions on the effects of meditation practices in healthcare cannot be drawn based on the available evidence. The review suggested that future research on meditation practices must be more rigorous in the design and execution of studies and in the analysis and reporting of results. [Ospina MB, 2007]

Another review, published in 2013, titled Yoga as a Therapeutic Intervention for Adults with Acute and Chronic Health Conditions [McCall MC, 2013], identified 2202 titles, of which 41 full-text articles were assessed for eligibility and 26 systematic reviews satisfied inclusion criteria. Thirteen systematic reviews included quantitative data and six papers included meta-analysis. Sixteen different types of health conditions were included. Eleven reviews showed tendency towards positive effects of yoga intervention, 15 reviews reported unclear results, and no reviews reported adverse effects of yoga. The authors concluded that although yoga appeared most effective for reducing symptoms in anxiety, depression, and pain, the quality of supporting evidence was low and that significant heterogeneity and variability in reporting interventions by type of yoga, settings, and population characteristics limited the generalizability of results.[McCall MC, 2013]

Another review by Verrastro also found inconsistent or limited-quality patient-oriented evidence for yoga as treatment for chronic back pain, depression, and anxiety.[Verrastro G, 2014]

Yet another review by Büssing A et al(2012) concluded thus: collectively, the available reviews suggest a number of areas where yoga may well be beneficial, but more research is required for virtually all of them to firmly establish such benefits; the heterogeneity among interventions and conditions studied has hampered the use of meta-analysis as an appropriate tool for summarizing the current literature; although there are some meta-analyses which indicate beneficial effects of yoga interventions, and there are several randomized clinical trials (RCT’s) of relatively high quality indicating beneficial effects of yoga for pain-associated disability and mental health….yoga cannot yet be a proven stand-alone, curative treatment; larger-scale and more rigorous research with higher methodological quality and adequate control interventions is highly encouraged. [Büssing A et al, 2012]

Now let us turn to individual diseases and conditions:

It is repeatedly and loudly being claimed that the so called yoga offers excellent solutions for all the modern, life style related diseases. But where is the evidence?

Cardiovascular Disease:

A systematic review of 37 RCTs and meta-analysis of 32 studies on the effectiveness of yoga in modifying risk factors for cardiovascular disease and metabolic syndrome [Chu P, 2014] concluded that there is promising evidence of yoga on improving cardio-metabolic health, but that the findings are limited by small trial sample sizes, heterogeneity, and moderate quality of RCTs. The review also found no significant difference between yoga and exercise.[Chu P, 2014]

A Cochrane review of studies on yoga for the primary prevention of cardiovascular disease [Hartley L, 2014] identified 11 trials (800 participants) and two ongoing studies, with different styles and duration of yoga. Most of studies were at risk of performance bias, with inadequate details reported in many of them to judge the risk of selection bias. No study reported cardiovascular mortality, all-cause mortality or non-fatal events, and most studies were small and short-term. Adverse events, occurrence of type 2 diabetes and costs were not reported in any of the included studies. There was substantial heterogeneity between studies making it impossible to combine studies statistically for systolic blood pressure and total cholesterol. Quality of life was measured in three trials but the results were inconclusive. The authors concluded that there is some evidence that yoga has favourable effects on diastolic blood pressure, HDL cholesterol and triglycerides, and uncertain effects on LDL cholesterol, but this limited evidence comes from small, short-term, low-quality studies and these results should be considered as exploratory and interpreted with caution. [Hartley L, 2014]

Another Cochrane review of yoga for secondary prevention of coronary heart disease [Kwong JSW, 2015] found no eligible RCTs that met the inclusion criteria of the review and thus the authors were unable to perform a meta-analysis. The authors concluded that the effectiveness of yoga for secondary prevention in CHD remains uncertain and that large RCTs of high quality are needed. [Kwong JSW, 2015]

A systematic review and meta-analysis on the effects of yoga on cardiovascular disease risk factors [Cramer H, Int J Cardiol. 2014] included 44 RCTs with a total of 3168 participants. It found the risk of bias to be high or unclear for most RCTs. The authors concluded that the meta-analysis revealed evidence for clinically important effects of yoga on most biological cardiovascular disease risk factors and recommended that yoga can be considered as an ancillary intervention for the general population and for patients with increased risk of cardiovascular disease, despite methodological drawbacks of the included studies.

Hypertension:

A systematic review and meta-analysis on the effectiveness of yoga for hypertension [Hagins M, 2013] included 17 studies, all of which had unclear or high risk of bias. Yoga had a modest but significant effect on systolic blood pressure(SBP) (-4.17 mmHg) and diastolic blood pressure(DBP) (-3.62 mmHg) (That’s right, yoga reduces SBP by 4mmHg and DBP by 3.6mm Hg and that is significant!). Subgroup analyses demonstrated significant reductions in blood pressure for interventions incorporating 3 basic elements of yoga practice (postures, meditation, and breathing) (SBP: -8.17 mmHg; DBP: -6.14 mmHg) but not for more limited yoga interventions; and for yoga compared to no treatment (SBP: -7.96 mmHg) but not for exercise or other types of treatment. The authors concluded that yoga can be preliminarily recommended as an effective intervention for reducing blood pressure, but additional rigorous controlled trials are warranted to further investigate the potential benefits of yoga. [Hagins M, 2013]

Another systematic review of yoga for essential hypertension included 6 studies involving 386 patients. The authors concluded that there is some encouraging evidence of yoga for lowering SBP and DBP, however, due to low methodological quality of these identified trials, a definite conclusion about the efficacy and safety of yoga on essential hypertension cannot be drawn from this review, and therefore, further thorough investigation, large-scale, proper study designed, randomized trials of yoga for hypertension will be required to justify the reported effects.[Wang J, 2013]

Yet another systematic review and meta-analysis of yoga for hypertension included seven RCTs with a total of 452 patients. Compared with usual care, very low-quality evidence was found for effects of yoga on systolic (6 RCTs, n = 278; mean difference (MD) = -9.65 mm Hg) and diastolic blood pressure (6 RCTs, n = 278; MD = -7.22 mm Hg). Subgroup analyses revealed effects for RCTs that included hypertensive patients but not for RCTs that included both hypertensive and prehypertensive patients, as well as for RCTs that allowed antihypertensive comedication but not for those that did not. More adverse events occurred during yoga than during usual care. Compared with exercise, no evidence was found for effects of yoga on systolic or diastolic blood pressure. The authors concluded that larger studies are required to confirm the emerging but low-quality evidence that yoga may be a useful adjunct intervention in the management of hypertension.[ Cramer H, Am J Hypertens. 2014]

Heart Failure:

A meta-analysis on the effects of yoga in patients with chronic heart failure included two studies, (total: 30 yoga and 29 control patients) and concluded that larger RCTs are required to further investigate the effects of yoga in patients with CHF.[Gomes-Neto M, 2014]

Heart rate variability:

A systematic review and meta-analysis of RCTs on yoga for heart rate variability included 14 trials of which only two were of acceptable methodological quality. Ten RCTs reported favourable effects of yoga on various domains of HRV, whereas nine of them failed to do so. One RCT did not report between-group comparisons. The meta-analysis of two trials did not show favourable effects of yoga compared to usual care and provided no convincing evidence for the effectiveness of yoga in modulating HRV in patients or healthy subjects.[Posadzki P, 2015]

Stroke:

A Review of yoga as an ancillary treatment for neurological and psychiatric disorders included 7 RCTs of yoga in patients with neurological disorders and 13 RCTs of yoga in patients with psychiatric disorders. The authors concluded that although the results are encouraging, additional RCTs are needed to critically define the benefits of yoga for both neurological and psychiatric disorders.[Meyer HB, 2012]

Another systematic review of yoga in stroke rehabilitation included 5 RCTs and concluded that modifications to different yoga practices make comparison between studies difficult, a lack of controlled studies precludes any firm conclusions on efficacy and recommended further research to evaluate these specific practices and their suitability in stroke rehabilitation.[Lazaridou A, 2013]

Two other reviews also concluded that there were flaws and inadequacies in the study designs, making it impossible to draw any conclusions, and recommended further research to validate the effects of yoga.[Lynton H, 2007; Mishra SK, 2012]

Diabetes Mellitus:

A systematic review of yoga practice for the management of type II diabetes mellitus in adults [Aljasir B, 2010] included five trials with a total of 362 patients. The mean number of participants was 72 (range 21 to 154). Overall trial quality was poor; two trials were graded B (moderate risk of bias) and three studies were graded C (high risk of bias). The authors concluded that no definitive recommendations could be made for physicians to encourage their patients to practice yoga. The important recommendation that was drawn from the review was the need for well-designed large randomised clinical trials to assess the effectiveness of yoga on type II diabetes.[Aljasir B, 2010]

A clinical review of complementary and alternative medicine therapies for diabetes [Birdee GS, 2010] concluded that the exercise intensity of yoga and tai chi has been categorized as low- to moderate-intensity; in controlled clinical trials, neither yoga nor tai chi has consistently demonstrated significant long-term improvements in glycemic control or A1C and overall, the quality of published research for mind-body interventions for patients with diabetes is poor, and more rigorous study is necessary.[Birdee GS, 2010]

Obesity:

Although Yoga is being promoted as a very useful tool against obesity, hardly any studies support this claim. There are also no systematic reviews or meta-analysis available. [Cramer H et al, BMC CAM, 2014] A review of yoga in the management of overweight and obesity admits that in contrast to data on comorbid conditions, data are more limited with regard to weight reduction and maintenance. Authors of this review write that studies on yoga and weight loss are challenged by small sample sizes, short durations, and lack of control groups, and that there is little consistency in terms of duration of formal group yoga practice sessions, duration of informal practices at home, and frequency of both. Yet, the same authors go on to assert that yoga appears promising as a way to assist with behavioral change, weight loss, and maintenance![ Bernstein AM, 2014]

Cancers:

Many studies have been done on the usefulness of yoga in the management of patients with cancers.

A meta-analysis aimed to determine the effects of yoga on psychological health, quality of life, and physical health of patients with cancer [Lin KY, 2011] included 10 studies and concluded that due to the mixed and low to fair quality and small number of studies conducted, the findings are preliminary and limited and should be confirmed through higher-quality, randomized controlled trials.

A Cochrane review on yoga in addition to standard care for patients with haematological malignancies included a single trial with 39 participants and concluded that there are not enough data to say how effective yoga is in the management of haematological malignancies, and therefore, the role of yoga for haematological malignancies remains unclear, and further large, high-quality randomised controlled trials are needed. [Felbel S, 2014]

Another systematic review and meta-analysis on yoga for breast cancer patients and survivors included 12 RCTs with a total of 742 participants. Evidence was found for short-term effects on global health-related quality of life and spiritual well-being; these effects were, however, only present in studies with unclear or high risk of selection bias. Short-term effects on psychological health also were found. Subgroup analyses revealed evidence of efficacy only for yoga during active cancer treatment but not after completion of active treatment. The authors concluded that the systematic review found evidence for short-term effects of yoga in improving psychological health in breast cancer patients, but the short-term effects on health-related quality of life could not be clearly distinguished from bias.[Cramer H, BMC Cancer 2012]

Mental Health:

Another domain wherein the benefits of yoga are claimed is mental health. Many psychiatrists have started recommending yoga in the treatment of a variety of psychiatric disorders. Even institutes of excellence such as the National Institute of Mental Health and Neurociences, Bangaluru, have opened Yoga Therapy Centres.

The NIMHANS web site has this information on its Yoga Centre: The National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India, being a pioneer institute for psychiatric and neurological services, has been conducting research in yoga since the early 1970’s. Considering the popularity of yoga, it was thought essential to establish an Advanced Yoga Therapy Centre in specialized fields of Medicine. Thus, the Advanced Centre for Yoga- Mental health and Neurosciences, a facility funded by the Ministry of Health, Govt. of India, was established at NIMHANS, Bangalore in November 2007. This centre was dedicated to Yoga promotion, training and research. The Advanced Centre provided service for patients and their caregivers suffering from psychiatric and neurological conditions, and also carried out pioneering research into the use of Yoga in neuropsychiatric conditions… NIMHANS has now established the Integrated Centre for Yoga to carry on the work of the Advanced Centre. [Advanced Centre for Yoga at http://nimhans.ac.in/nimhans/advanced-centre-yoga] So, a premier institute of evidence based medicine such as NIMHANS deems it appropriate to open a Yoga Center, considering the popularity of Yoga!



But where is the evidence for the benefits of yoga in the treatment of psychiatric illness?

A systematic review of yoga for neuropsychiatric disorders included 16 of the 124 trails that met rigorous criteria. It found Grade B evidence (sparse high grade data or substantial amount of low grade data) for a potential acute benefit in depression (four RCTs), for schizophrenia as an adjunct to pharmacotherapy (three RCTs), and in children with ADHD (two RCTs), and Grade C evidence (low grade data without the volume) in sleep complaints (three RCTs). RCTs in cognitive disorders and eating disorders yielded conflicting results. The authors concluded that biomarker and neuroimaging studies, those comparing yoga with standard pharmaco- and psychotherapies, and studies of long-term efficacy are needed to fully translate the promise of yoga for enhancing mental health.[Balasubramaniam M, 2013]

Another review of yoga in neuro-psychiatry concluded that the available research is limited by small sample size, few randomized studies, inadequate control, diversely modified yoga practices, limited assessments and lack of safety data that preclude any firm conclusions on efficacy of yoga on the various psychiatric and neurological disorders. The authors advocated requirement of more research to decisively assess the validity of applying yoga as a mainstream therapeutic treatment for neuro-psychiatric disorders.[ Anand KS, 2014]

Anxiety:

A Cochrane review on meditation therapy for anxiety disorders included two RCTs of moderate quality that used active control comparisons. The overall dropout rate in both studies was high (33-44%). Neither study reported on adverse effects of meditation. The authors concluded that the small number of studies included in the review do not permit any conclusions to be drawn on the effectiveness of meditation therapy for anxiety disorders and suggested that more trials are needed. [Krisanaprakornkit T, 2006]

Yet another review of CAM for anxious patients concluded that only few controlled studies evaluated yoga for anxiety disorders, and all have significant methodologic limitations and/or poor methodology reporting; the diagnostic conditions treated and both yoga interventions and control conditions varied; there is little information regarding safety or contraindications of yoga; the reported attrition rates were high in most studies, which may raise concerns about patient motivation and compliance.[Antonacci DJ et al, 2010]

Depression:

A systematic review and meta-analysis of yoga for depression included 12 RCTs with 619 participants. There was moderate evidence for short-term effects of yoga compared to usual care and limited evidence compared to relaxation and aerobic exercise. Limited evidence was found for short-term effects of yoga on anxiety compared to relaxation. Due to the paucity and heterogeneity of the RCTs, no meta-analyses on long-term effects were possible. No RCT reported safety data. [Cramer H, Depression and Anxiety 2013]

Schizophrenia:

A systematic review and meta-analysis of yoga for schizophrenia included five RCTs with a total of 337 patients. No evidence was found for short-term effects of yoga compared to usual care on positive symptoms, moderate evidence was found for short-term effects on quality of life compared to usual care and these effects were only present in studies with high risk of bias. No evidence was found for short-term effects on social function. Comparing yoga to exercise, no evidence was found for short-term effects on positive symptoms, negative symptoms, quality of life, or social function. The authors concluded that the systematic review found only moderate evidence for short-term effects of yoga on quality of life, and as these effects were not clearly distinguishable from bias and safety of the intervention was unclear, no recommendation could be made regarding yoga as a routine intervention for schizophrenia patients.[Cramer H, BMC Psychiatry 2013]

Menopausal Symptoms:

A systematic review and meta-analysis of RCTs on the effectiveness of yoga for menopausal symptoms included 5 RCTs with 582 participants in the qualitative review, and 4 RCTs with 545 participants in the meta-analysis. There was moderate evidence for short-term effects on psychological symptoms, but no evidence was found for total menopausal symptoms, somatic symptoms, vasomotor symptoms, or urogenital symptoms. Authors recommended more rigorous research to underpin these results, and recommended yoga as a preliminary, additional intervention for women who suffer from psychological complaints associated with menopause.[ Cramer H, EBCAM 2012]

Multiple Sclerosis:

A systematic review and meta-analysis of studies on yoga for multiple sclerosis included 7 RCTs with a total of 670 patients. Evidence for short-term effects of yoga compared to usual care were found for fatigue and mood, but not for health-related quality of life, muscle function, or cognitive function. The effects on fatigue and mood were not robust against bias. No short-term or longer term effects of yoga compared to exercise were found. The authors concluded that since no methodological sound evidence was found, no recommendation could be made regarding yoga as a routine intervention for patients with multiple sclerosis.[ Cramer H, PLoS ONE, 2014]

Epilepsy:

A Cochrane review of yoga for epilepsy included two unblinded trials with a total of 50 people. Although yoga showed possible beneficial effects, no reliable conclusions could be drawn regarding the efficacy of yoga as a treatment for uncontrolled epilepsy, in view of methodological deficiencies such as limited number of studies, limited number of participants randomised to yoga, lack of blinding and limited data on quality-of-life outcome. Authors recommended further high-quality research is needed to fully evaluate the efficacy of yoga for refractory epilepsy.[ Panebianco M, 2015]

Back Ache:

Yoga has been studied extensively in the treatment of back ache and some systematic reviews have found it to have some benefits.

A systematic review and meta-analysis of yoga for low back pain included 10 RCTs with a total of 967 chronic low back pain patients. Eight studies had low risk of bias. There was strong evidence for short-term effects on pain, back-specific disability, and global improvement. There was strong evidence for a long-term effect on pain and moderate evidence for a long-term effect on back-specific disability. There was no evidence for either short-term or long-term effects on health-related quality of life. The authors concluded that yoga can be recommended as an additional therapy to chronic low back pain patients.[Cramer H, Clin J Pain. 2013]

Rheumatic Diseases:

A systematic review of yoga for rheumatic diseases included 8 RCTs with a total of 559 subjects. In two RCTs on fibromyalgia syndrome, there was very low evidence for effects on pain and low evidence for effects on disability. In three RCTs on osteoarthritis, there was very low evidence for effects on pain and disability. Based on two RCTs, very low evidence was found for effects on pain in rheumatoid arthritis. No evidence for effects on pain was found in one RCT on carpal tunnel syndrome. No RCT explicitly reported safety data. The authors concluded that only weak recommendations could be made for the ancillary use of yoga in the management of FM syndrome, OA and RA.[Cramer H, Rheumatology (Oxford). 2013]

Fibromyalgia:

A systematic review and meta-analysis of RCTs on the efficacy and safety of meditative movement therapies such as Qigong, Tai Chi and Yoga in fibromyalgia syndrome included 7 studies with 362 subjects. Yoga had short-term beneficial effects on some key domains of FMS, and the authors recommended that there is a need for high-quality studies with larger sample sizes to confirm the results.[Langhorst J, 2013]

Carpal Tunnel Syndrome:

A Cochrane review of non-surgical treatment (other than steroid injection) for carpal tunnel syndrome included one trial of yoga involving 51 people and yoga significantly reduced pain after eight weeks compared with wrist splinting. The authors concluded that more trials are needed to compare treatments and ascertain the duration of benefit.[O’Connor D, 2003]

Fatigue:

A meta-analysis on the effects of yoga interventions on fatigue included 19 clinical studies with a total of 948 patients suffering from cancer, multiple sclerosis, dialysis, chronic pancreatitis, fibromyalgia, asthma, or nothing. Overall, the effects of yoga interventions on fatigue were only small, particularly in cancer patients and the authors concluded that the meta-analysis was not able to define the powerful effect of yoga on patients suffering from fatigue.[Boehm K, 2012]

Chronic Obstructive Pulmonary Disease:

A Cochrane review of breathing exercises for chronic obstructive pulmonary disease included 16 studies, of which two were of yoga, with a total of 74 patients. All types of breathing exercises over four to 15 weeks improved functional exercise capacity in people with COPD compared to no intervention; however, there were no consistent effects on dyspnoea or health-related quality of life. The authors concluded that the treatment effects for patient-reported outcomes may have been overestimated owing to lack of blinding and that these data do not suggest a widespread role for breathing exercises in the comprehensive management of people with COPD.[Holland AE, 2012]

Asthma:

A systematic review of RCTs for yoga for asthma included 6 RCTs and one NRCT. Their methodological quality was mostly poor. Three RCTs and one NRCT suggested that yoga leads to a significantly greater reduction in spirometric measures, airway hyperresponsivity, dose of histamine needed to provoke a 20% reduction in forced expiratory volume in the first second, weekly number of asthma attacks, and need for drug treatment. Three RCTs showed no positive effects compared to various control interventions. According to the authors, the belief that yoga alleviates asthma is not supported by sound evidence and further, more rigorous trials are warranted.[Posadzki P, 2011]

Yet another systematic review of RCTs for yoga for asthma included 14 RCTs with 824 patients. No effect was robust against all potential sources of bias and the authors concluded that yoga cannot be considered a routine intervention for asthmatic patients at this point.[Cramer H, Ann Allergy Asthma Immunol.2014]

Conditions affecting veterans:

A review of yoga interventions for conditions affecting veterans concluded that yoga can improve functional outcomes in patients with nonspecific chronic low back pain, but the existing evidence was found to be less clear about the effectiveness and safety of yoga for the other conditions of interest, and also that the quality of the primary studies was generally poor. The authors found few or no trials that evaluated the effectiveness and safety of yoga for prevention of falls, PTSD, or insomnia.[Coeytaux RR, 2014]

Stress and Memory:

Another review on the effects of yoga on stress response and memory concluded that due to the shortage of empirical evidence, along with several shared methodological limitations, further investigation is still needed to fully determine the efficacy of yoga as a beneficial mind-body therapy for decreasing both perceived and physiological stress-response, improving memory, and preventing stress and age-related hippocampal volume loss.[Longstreth H, 2014]

A review of the studies on the effect of meditation on cognitive functions in context of aging and neurodegenerative diseases found the conclusions of these studies to be limited by their methodological flaws and differences of various types of meditation techniques.[Marciniak R, 2014]

Children and Adolescents:

Yoga is being promoted in schools and colleges with a claim that it helps to improve physical as well as mental health of children and adolescents and that it helps to improve their concentration and memory. But where is the evidence?

A review of yoga for children and young people’s mental health and well-being that quite strongly suggests that yoga could provide tools for children and young people to remain centered or regain focus, so they may cope with the stress and challenges they experience in their everyday lives, goes on to conclude that there are gaps in the research pertaining to the relationship between various yoga techniques/practices and mental health benefit and that there is also a lack of empirical evidence evaluating the correlation between specific yoga practices and developmental milestones among young people.[Hagen I, 2014]

A systematic review of the literature on the therapeutic effects of yoga for children, published in 2008, concluded that larger clinical trials, including specific measures of quality of life were necessary to provide definitive evidence.[Galantino ML, 2008]

ADHD:

A Cochrane review of meditation therapies for attention-deficit/hyperactivity disorder (ADHD) included 4 studies, two of mantra meditation and two of yoga. Design limitations caused high risk of bias across the studies and only one out of four studies provided data appropriate for analysis. There was no statistically significant difference between the meditation therapy group and the drug therapy group on the teacher rating ADHD scale and in the distraction test. The authors concluded that as a result of the limited number of included studies, the small sample sizes and the high risk of bias, they were unable to draw any conclusions regarding the effectiveness of meditation therapy for ADHD.[Krisanaprakornkit T, 2010]

Another review of yoga in the treatment of children with ADHD concluded that at present the small number of available investigations renders it impossible to draw any conclusions regarding the effectiveness of yoga for ADHD in children and that large, well-controlled, randomized trials are needed in order to establish the potential value of yoga as a single treatment or adjunct to standard ADHD therapies.[Lange KM, 2014]

Safety of Yoga:

And yoga, as is being promoted today, is not safe either. Anand KS and Rohit Verma caution thus: Although yoga is suggested to be relatively safe and well tolerated, there are risks of overstretching, strains, fractures and dehydration. It can worsen glaucoma as the inverted asanas increase the intraocular pressure by raising episcleral venous pressure and choroidal volume due to vascular enlargement. Inverted postures pose the risk of a sudden drop in blood pressure, which can induce a stroke or heart attack particularly in susceptible individuals. Bikram yoga, which is practiced in very hot temperatures, is likely risky for patients with multiple sclerosis. It must be noted that majority of RCTs have not reported any safety data on yoga.[Anand KS, 2014]

Another review by Cramer et al also cautions that yoga should be practiced carefully under the guidance of a qualified instructor. Beginners should avoid extreme practices such as headstand, lotus position and forceful breathing. Individuals with medical preconditions should work with their physician and yoga teacher to appropriately adapt postures; patients with glaucoma should avoid inversions and patients with compromised bone should avoid forceful yoga practices.[Cramer H, PLoS One. 2013] [Also see Broad WJ. How Yoga Can Wreck Your Body. The New York Times Jan. 5, 2012]

So, where is the evidence for the claim that yoga can cure or prevent any ailment? Where is the Satya in the practice of Yoga?

(Edited on 21st June 2014 to include the sections on Children and Adolescents, Safety of Yoga and the References.)

References:

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