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Evidence-Based Complementary and Alternative Medicine
Volume 2012, Article ID 165410, 7pages
doi:10.1155/2012/165410
Review Article
Effects of Yoga on Mental and Physical Health:
A Short Summary of Reviews
Arndt B ¨
ussing,1Andreas Michalsen,2Sat Bir S. Khalsa,3
Shirley Telles,4and Karen J. Sherman5
1Department Quality of Life, Spirituality and Coping, Center of Integrative Medicine, Faculty of Health,
Witten/Herdecke University, 58313 Herdecke, Germany
2Department of Internal and Complementary Medicine, Immanuel Hospital Berlin and Institute of Social Medicine,
Epidemiology & Health Economics, Charit´
e-University Medical Center, 14109 Berlin, Germany
3Division of Sleep Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
4Director of Research, Patanjali Research Foundation, Haridwar 249405, India
5Group Health Research Institute, Group Health Cooperative, Seattle, WA 98101, USA
Correspondence should be addressed to Arndt B¨
ussing, arndt.buessing@uni-wh.de
Received 4 May 2012; Revised 4 July 2012; Accepted 18 July 2012
Academic Editor: Vernon A. Barnes
Copyright © 2012 Arndt B ¨
ussing et al. This is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
This report summarizes the current evidence on the effects of yoga interventions on various components of mental and physical
health, by focussing on the evidence described in review articles. Collectively, these 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. Nevertheless, 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 may well be effective as a supportive adjunct to mitigate some medical conditions, but not yet a proven
stand-alone, curative treatment. Larger-scale and more rigorous research with higher methodological quality and adequate control
interventions is highly encouraged because yoga may have potential to be implemented as a beneficial supportive/adjunct
treatment that is relatively cost-effective, may be practiced at least in part as a self-care behavioral treatment, provides a life-long
behavioural skill, enhances self-efficacy and self-confidence and is often associated with additional positive side effects.
1. Introduction
The conceptual background of yoga has its origins in ancient
Indian philosophy. There are numerous modern schools
or types of yoga (i.e., Iyengar, Viniyoga, Sivananda, etc.),
each having its own distinct emphasis regarding the relative
content of physical postures and exercises (asanas), breathing
techniques (pranayama), deep relaxation, and meditation
practices that cultivate awareness and ultimately more pro-
found states of consciousness. The application of yoga as a
therapeutic intervention, which began early in the twentieth
century, takes advantage of the various psychophysiolog-
ical benefits of the component practices. The physical
exercises (asanas) may increase patient’s physical flexibility,
coordination, and strength, while the breathing practices
and meditation may calm and focus the mind to develop
greater awareness and diminish anxiety [1], and thus result
in higher quality of life. Other beneficial effects might involve
a reduction of distress, blood pressure, and improvements in
resilience, mood, and metabolic regulation [2].
Khalsa stated that a majority of the research on yoga as
a therapeutic intervention was conducted in India and a sig-
nificant fraction of these were published in Indian journals,
some of which are difficult to acquire for Western clinicians
and researchers [3]. In their bibliometric analysis from 2004,
they found that 48% of the enrolled studies were uncon-
trolled, while 40% were randomized clinical trials (RCT),
and 12% non-RCT (N-RCT). Main categories which were
2 Evidence-Based Complementary and Alternative Medicine
addressed were psychiatric, cardiovascular, and respiratory
disorders [3].
Despite a growing body of clinical research studies and
some systematic reviews on the therapeutic effects of yoga,
there is still a lack of solid evidence regarding its clinical rele-
vance for many symptoms and medical conditions. For many
specific indications and conditions, there is inconsistent
evidence with several studies reporting positive effects of
the yoga interventions, but other studies are less conclusive.
In some instances, these discrepancies may result from dif-
ferences between the study populations (e.g., age, gender,
and health status), the details of the yoga interventions, and
follow-up rates.
In this paper, we summarize the current evidence on the
clinical effects of yoga interventions on various components
of mental and physical health. In general, the respective
reviews (Tab le 1) and an Agency for Healthcare Research
and Quality Report (AHRQ) evidence report on “Meditation
Practices for Health,” which cites also studies on yoga [30],
include a heterogeneous set of studies with varying effect
sizes, heterogeneous diagnoses and outcome variables, often
limited methodological quality, small sample sizes, varying
control interventions, different yoga styles, and strongly
divergent duration of interventions.
2.YogaandMentalHealth
2.1. Depression. We found four relevant publications, includ-
ing two reviews on the effects of yoga on depression [4,5],
a description of studies on yogic breathing [6] for depres-
sion, and one “summary” [8]. The reviewing authors have
reported that the studies reviewed showed a large variety of
diagnoses ranging from “major depression or some other
type of diagnosed depression” to “elevated depressive symp-
toms” [5]. Although several randomized controlled trials
(RCTs) reported beneficial effects of yoga interventions for
treating depressive symptoms, the quality and quantity of
the data from these studies appear insufficient to conclude
whether there is substantial clinical justification to consider
yoga as a treatment of depression. Compared to passive con-
trols, the yoga interventions seem to be effective; when com-
pared with active controls, not surprisingly, the effects are less
conclusive [5].Thestudyresultsaresofarnotsufficient in
quantity and quality to determine whether studies with a
focus on the asanas are more effective as compared to stud-
ies with meditation-focussed or pranayama-focussed styles.
Thus, there is a strong need to conduct more conclusive
studies with high methodological quality and larger patient
samples. Whether motivation of depressed patients could be
a problem or not remains to be clarified. There has been an
attempt to explore mechanisms of action and to understand
the complete picture of the effects of yoga in depression look-
ing at electrophysiological markers of attention, and neu-
rotransmitters which were found to change with yoga [7,31].
2.2. Fatigue. We found one systematic review/meta-analysis
evaluating the effects of yoga on fatigue in a variety of med-
ical conditions. The review included 19 RCTs and included
Tab le 1: Systematic reviews for the different domains discussed.
Indications Studies on yoga interventions
Depression
2 reviews [4,5],
1 description of studies on
yogic breathing [6,7],
1 summary [8]
Fatigue 1 systematic review [9]
Anxiety and anxiety disorders
1systematicreview[1],
1 Cochrane review on
meditation therapy [10],
1 description of studies on
yogic breathing [6,7],
1 summary [8]
Stress 1systematicreview[11]
Posttraumatic stress disorder 1 review article [12]
Physical fitness 1 critical review [13]
Sympathetic/parasympathetic
activation 1systematicreview[14]
Cardiovascular endurance 1 review [15]
Blood pressure and hypertension 1 systematic review [14]
Pulmonary function 1 review [15]
Glucose regulation 3systematicreviews
[14,16,17]
Menopausal symptoms 1review[18],
1systematicreview[19]
Musculoskeletal functioning
and pain
3 systematic reviews [20–22],
2 reviews [23,24]
Cancer 2 reviews [25,26],
2 meta-analyses [27,28]
Epilepsy 1 Cochrane review [29]
healthy persons as well as patients with cancer, multiple
sclerosis, dialysis, chronic pancreatitis, fibromyalgia, and
asthma [9]. Overall, a small positive effect with an SMD
of 0.28 [0.24–0.33] was found. This standardized mean
difference (SMD) describes the difference in the group mean
values divided by the respective standard deviation; a value
between 0.3 and 0.5 can be regarded as small, SMD between
0.5 and 0.8 as moderate, and SMD >0.8 as large. For those
studies that included cancer patients (n=10), the treatment
effect of yoga was 0.20 (0.15–0.24); for all other studies that
did not include cancer patients (n=9), the effect was
0.46 (0.24–0.67) [9]. Nevertheless, there are some studies on
cancer-related fatigue which indicate that treatment effects of
yoga could be improved in well-designed future studies.
2.3. Anxiety and Anxiety Disorders. There is one systematic
review examining the effects of yoga on anxiety and anxiety
disorders [1], a Cochrane review on meditation therapy for
anxiety disorders [10] (citing one yoga study [32]), a descrip-
tion of studies on yogic breathing (which are also addressed
in the systematic review) [6], and one summary [8].
Most studies described beneficial effects in favour of the
yoga interventions, particularly when compared with passive
controls (i.e., examination anxiety), but also compared with
active controls such as relaxation response or compared
Evidence-Based Complementary and Alternative Medicine 3
to standard drugs. However, there are currently no meta-
analyses available which would clearly differentiate this
important issue. At least the AHRQ report stated that “yoga
was no better than Mindfulness-based Stress Reduction at
reducing anxiety in patients with cardiovascular diseases”
[30].
2.4. Stress. One systematic review describes the effects of
yoga on stress-associated symptoms. Chong et al. identified 8
controlled trials, 4 of which were randomized, which fulfilled
their selection criteria [11]. Most studies described beneficial
effects of yoga interventions. Although not all studies used
adequate and/or consistent instruments to measure stress,
they nevertheless indicate that yoga may reduce perceived
stress as effective as other active control interventions such
as relaxation, cognitive behavioural therapy, or dance.
Also the AHRQ report stated that “yoga helped reduce
stress” [30]. Here, the two included studies showed a signi-
ficant reduction of stress scores in favour of the yoga group
(SMD =−1.10 [CI: −1.61 to −0.58].
Posttraumatic Stress Disorder. A single review article looked
at the existing research on yoga for posttraumatic stress
disorder (PTSD) [12]. Seven articles were reviewed which
included 8 studies on PTSD following exposure to natural
disasters such as a tsunami and a hurricane (1 RCT, 1 N-
RCT, 3 group study, 2 single-arm studies, 1 cross-sectional
study) and 2 studies on PTSD due to combat and terrorism
(1 RCT, 1 single-arm study). After a natural disaster, yoga
practice was reported to significantly reduce symptoms of
PTSD, self-rated symptoms of stress (fear, anxiety, disturbed
sleep, and sadness) and respiration rate. Similarly, yoga
interventions were able to improve the symptoms of PTSD in
persons with PTSD after exposure to combat and terrorism.
The interventions varied in duration from one week (when
interventions were given on the site) to six months. The
review suggested a possible role of yoga in managing PTSD,
though long-term studies conducted with greater rigor are
needed [12].
3.YogaandPhysicalFitness
3.1. Physical Fitness. Therewasonecriticalreviewwhich
evaluated whether yoga can engender fitness in older adults
[13]. Ten studies with 544 participants (mean age 69.9±6.3)
were included; 5 of these studies were RCTs, and 5 studies had
a single-arm pre/post-design. With respect to physical fitness
and function, the studies reported moderate effect sizes for
gait, balance, body flexibility, body strength, and weight loss
[13]. However, there is still a need for additional research
trials with adequate control interventions (active and spe-
cific) to verify these promising findings.
One may expect that retaining physical fitness and
improving physical functioning can have a positive effect on
functional abilities and self-autonomy in older adults. Fur-
ther studies should address whether or not individuals’ self-
esteem and self-confidence will increase during the courses,
and whether or not regular classes may also improve social
competence and involvement. A problem with studies
enrolling elderly subjects can be compliance with the study
protocol leading to low levels of study completion and long-
term follow-up data. Future studies should investigate the
most appropriate duration of yoga intervention and the most
suitable postures and yoga style for the elderly.
3.2. Sympathetic/Parasympathetic Activation. There were 42
studies on the yoga effects on sympathetic/parasympathetic
activation and cardiovagal function [14], that is, 9 RCTs, 16
non-RCTs, 15 uncontrolled trials, and 2 cross-sectional trials.
Most studies offered“someevidencethatyogapromotesa
reduction in sympathetic activation, enhancement of cardio-
vagal function, and a shift in autonomic nervous system bal-
ance from primarily sympathetic to parasympathetic” [14].
However, some of the studies included in the review showed
less clear-cut or even contrasting, effects. Because most of
these effects are short-term phenomena, more rigorous work
is needed.
Another lacuna is that there are very few studies which
have studied plasma catecholamine levels and most of them
are early studies [33,34].
3.3. Cardiovascular Endurance. Raub’s literature review, which
included 7 controlled studies, reported “significant improve-
ments in overall cardiovascular endurance of young subjects
who were given varying periods of yoga training (months
to years)” [15]. Outcome measures included oxygen con-
sumption, work output, anaerobic threshold, and blood
lactate during exercise testing. As expected, physical fitness
increased in adolescents or young adults (athletes and
untrained individuals) compared to other forms of exercise,
withalongerdurationofyogapracticeresultedinbetter
cardiopulmonary endurance.
4. Yoga and Cardiopulmonary Conditions
4.1. Blood Pressure and Hypertension. Innesetal.reportedon
37 studies investigating the effects of yoga on blood pressure
and hypertension, among them 12 RCTs, 12 nonrandomized
clinical trials, 11 uncontrolled studies, 1 cross-sectional
study, and 1 single yoga session examination. Most reported
a reduction of systolic and/or diastolic pressure. However,
there were several noted potential biases in the studies
reviewed (i.e., confounding by lifestyle or other factors) and
limitations in several of the studies which makes it “difficult
to detect an effect specific to yoga” [14].
Ospina et al.’s AHRQ cites two studies which found
small, insignificant improvements of systolic (weighted mean
difference =−8.10; 95% CI, −16.94 to 0.74) and diastolic
blood pressure (weighted mean difference =−6.09; 95% CI,
−16.83 to 4.64) in favour of yoga when compared to no
treatment [30]. When compared to health education, yoga
interventions resulted only in small and insignificant
improvements of systolic blood pressure (weighted mean
difference =−15.32; 95% CI, −38.77 to 8.14) and diastolic
blood pressure (weighted mean difference =−11.35; 95% CI,
−30.17 to 7.47) [30].
4 Evidence-Based Complementary and Alternative Medicine
4.2. Pulmonary Function. In his descriptive literature review,
Raub also examined studies evaluating yoga’s effects on lung
function in healthy volunteers and patients with chronic
bronchitis and asthma [15]. In healthy volunteers practicing
yoga, there are reported improvements of various parameters
of lung function with breathing control techniques, specific
postures, and/or relaxation techniques [15]. However, these
improvements were “not consistent and depended upon
the length of yoga training, the type of yoga practice used
(e.g., breathing exercises and yoga postures), and the type
of subject” [15]. Raub also cited some studies on patients
with asthma describing improvements in peak expiratory
flow rate, medication use and asthma attack frequency. In a
double-blinded RCT with placebo-control, [35] there were
only a few small and insignificant improvements in lung
function variables. Thus, more rigorous trials are needed to
clarify the value of yoga breathing practices for patients with
asthma.
5. Yoga and Metabolic/Endocrine Conditions
5.1. Glucose Regulation. Three systematic reviews examined
the effects of yoga on risk indices associated with insulin
resistance syndrome [14], risk profiles in adults with type
2 diabetes mellitus [16], and the management of type 2
diabetes mellitus [17]. Innes et al. [14] identified several
studies on the effects of yoga on insulin resistance syndrome-
associated variables, that is, 2 RCTs, 2 non-RCTs, and 8
uncontrolled clinical trials. These studies reported postinter-
vention improvement in various indices in adults. However,
the results varied by population (healthy adults, adults at
cardiovascular disease risk, adults with type 2 diabetes, etc.)
and study design.
Another systematic review by Aljasir et al. [17] addressed
the management of type 2 diabetes mellitus and concluded
that the reviewed trials “suggest favourable effects of yoga on
short-term parameters related to diabetes but not necessarily
for the long-term outcomes.” However, the duration of
treatment in the reviewed studies was variable (ranging from
20 min. session per day to three to five 90min. sessions in
the review of Aljasir et al. [17];3-4hperdayfor8days,2
sessions per day (25–35 min) for 3 months to 40min per day
for 6 months, and 72 4 h sessions during 12 months in the
review by Innes and Vincent [16]).
The AHRQ cites two studies comparing yoga versus
medication which reported a large and significant reduction
of fasting glucose in individuals with type 2 diabetes in one
study, and a smaller but still significant improvement in the
other study [30]. The authors discussed differences in the
study populations, and interventions as possible explanation
for the observed heterogeneity of results.
5.2. Menopausal Symptoms. A single review addressed
menopausal symptoms and analyzed 3 RCT, 1 N-RCT, and 3
uncontrolled clinical trials [18]. Although some studies
reported beneficial effects, “the evidence was insufficient to
suggest that yoga is an effective intervention for menopause”
[18].
A recent systematic review included 5 RCTs, which
addressed effects of yoga on menopausal symptoms, partic-
ularly psychological symptoms, somatic symptoms, vasomo-
tor symptoms, and/or urogenital symptoms [19]. However,
yoga was associated with small effects on psychological
symptoms (SMD =−0.37; 95% CI −0.67 to −0.07; P=
0.02), but no effects on “total menopausal symptoms, soma-
tic symptoms, vasomotor symptoms, or urogenital symp-
toms” [19].
6. Yoga and Musculoskeletal Conditions
6.1. Musculoskeletal Functioning and Pain. There were 3 sys-
tematic reviews [20–22] and 2 other reviews on the effects of
yoga on musculoskeletal function, chronic pain conditions,
and pain-associated disability [23,24]. Two reviews specifi-
cally addressed low back pain [22,24] or arthritis [23], while
the other reviews summarized studies on various chronic
pain conditions, most with a focus on musculoskeletal
conditions and associated disability.
Posadzki et al. [21] included 11 RCTs with variable
methodological quality and found that 10 of 11 studies
reported significantly greater effects in favor of yoga when
compared to “standard care, self care, therapeutic exercises,
relaxing yoga, touch and manipulation, or no intervention.”
A recent meta-analysis on pain intensity/frequency, and
pain-related disability included 5 RCTs with single blinding,
7 RCTs without blinding, and 4 non-RCTs [20]. Reviewed
studies included yoga for the treatment of back pain (6
studies), rheumatoid arthritis (2 studies), headache/migraine
(2 studies), and other indications (i.e., hemodialysis, irritable
bowel syndrome, labor pain, etc.). All of these studies
reported positive effects in favor of the yoga interventions.
There were moderate treatment effects with respect to 5 pain
(SMD =−0.74 [CI: −0.97 to −0.52], P<0.0001), and pain-
related disability (SMD =−0.79 [CI: −1.02 to −0.56], P<
0.0001). Despite some study limitations, there was evidence
that yoga may be useful for several pain-associated disorders.
Thus, well-designed larger scale studies with adequate con-
trols for confounding factors and more thorough statistical
analyses are needed to verify these promising findings.
With respect to chronic back pain, the studies indicate
that yoga was more effective than the control interventions
(including usual care or conventional therapeutic exercises),
albeit some studies showed no between group difference
[22]. Two recent and properly powered trials of yoga for back
pain were published and reported clinically meaningful ben-
efits for yoga over usual medical care from 6- to 12-months
postrandomization [36,37], but not over an intensive
stretching intervention [36].
7. Yoga and Specific Diseases
7.1. Cancer. With respect to cancer, there are 2 reviews
[25,26] and 2 meta-analyses (one with 10 studies [27], and
one “letter to the editor” with 6 studies [28]). According to
the findings of the more comprehensive meta-analysis of Lin
et al., the yoga groups showed improvements in psycholog-
ical health when compared to waitlist or supportive therapy
Evidence-Based Complementary and Alternative Medicine 5
groups, that is, anxiety (8 studies: SMD =−0.76 [−1.34 to
−0.19], P=0.009), depression (8 studies: SMD =−0.95
[−1.55 to −0.36], P=0.002), distress (2 studies: SMD =
−0.4 [−0.67 to −0.14], P=0.003), and stress (5 studies;
SMD =−0.95 [−1.63 to −0.27], P<0.006) [27]. With
respect to overall quality of life, there was just a trend towards
improvement (SMD =−0.29 [−0.58 to 0.001], P=0.06).
To explain the positive outcomes, Smith and Pukall suggested
that complex pathways which may involve relaxation, coping
strategies, acceptance, and self-efficacy [26]. Although Lin
et al. stated that the “findings are preliminary and limited
and should be confirmed through higher-quality, random-
ized controlled trials,” they nevertheless attested “potential
benefit of yoga for people with cancer in improvements of
psychological health” [27]. However, the outcome parame-
ters described in these cancer reviews were also addressed in
the symptom-specific reviews described above.
7.2. Epilepsy. To assess the potential effects of yoga in the
treatment of epilepsy, 1 Cochrane review analyzed 1 RCT and
1 N-RCT [29]. However, the authors were not able to draw
“reliable conclusions” whether yoga may be effective or not.
8. Discussion
These reviews suggest a number of areas where yoga may be
beneficial, but more research is required for virtually all of
them to more definitively establish benefits. However, this
is not surprising given that research studies on yoga as a
therapeutic intervention have been conducted only over the
past 4 decades and are relatively few in number. Typically,
individual studies on yoga for various conditions are small,
poor-quality trials with multiple instances for bias. In addi-
tion, there is substantial heterogeneity in the populations
studied, yoga interventions, duration and frequency of yoga
practice, comparison groups, and outcome measures for
many conditions (e.g., depression and pain). Disentangling
the effects of this heterogeneity to better understand the value
of yoga interventions under various circumstances is chal-
lenging. For many conditions, heterogeneity and poor qual-
ity of the original trials indicated that meta-analyses could
not be appropriately conducted. Nevertheless, some RCTs
of better quality found beneficial effects of yoga on mental
health (see Uebelacker et al.’s critical review [5]). Further
investigations in this area are recommended, particularly
because of the plausibility of the underlying psychophysio-
logical rationale (including the efficacy of frequent physical
exercises, deep breathing practices, mental and physical
relaxation, healthy diet, etc.).
While it is not surprising that physical fitness can be
improved by training, using either yoga or conventional
exercises, it is of interest that in individuals with pain yoga
may have beneficial effects with overall moderate effects sizes.
However, these effects were strong particularly in healthy
individuals, but much weaker in patients with chronic pain
conditions. The beneficial effects might be explained by an
increased physical flexibility, by calming and focusing the
mind to develop greater awareness and diminish anxiety,
reduction of distress, improvement of mood, and so forth.
Because patients may recognize that they are able to be
physically active, even despite of persisting pain symptoms,
they may therefore experience higher self-competence and
self-awareness, which contributes to higher quality of life.
Conceivably, asanas particularly have a positive effect on
fitness and physical flexibility with a secondary effect on
the mental state, while the pranayama practices and relax-
ation/meditation techniques may result in greater awareness,
less stress, and higher well-being and quality of life. However,
this remains to be shown in well-performed future studies.
Because patients are engaged in the yoga practices as
a self-care behavioural treatment, yoga interventions might
well increase self-confidence and self-efficacy. On the other
hand, patients with psychological burdens and/or low moti-
vation (i.e., depression, anxiety, fatigue, etc.) might be less
willing to participate fully in intensive yoga interventions.
Some of these studies found relatively low participation and
high dropout rates in some of the analysed studies. Patient
compliance may be higher with the social support within
group interventions, while private regular practices at home
mightbemoredifficult to perform consistently. These
factors need to be addressed in further studies. Innes et al.
[14] argued that most studies were from India where “yoga
is an integral part of a longstanding cultural and spiritual
tradition.” It is thus unclear whether adherence in Western
patients might be the same. Many of the Indian clinical trials,
which have been conducted in residential settings, not typ-
ically found outside India, include yoga class interventions
5 to 7 days per week, whereas such compliance would not
be possible with patient populations outside India. However,
such practices are unlikely to be continued, at least at such
intensity. If as believed by some yoga practitioners, the inten-
sity of the practice should be greater at the beginning of ther-
apy, such programs would be an excellent way to begin yoga
treatment. In India, there is a gradual shift in the attitude
towards yoga with most urban Indians under the age of 35
believing yoga is a way to keep fit rather than attaching the
same cultural importance to it, which earlier generations did.
For these reasons, cross-cultural studies (which are lacking)
using an identical intervention given to a population in India
and parallel conducted elsewhere would be very useful.
Motivation might be a crucial point. To overcome this,
shorter time interventions might be an option for some
specific indications (i.e., pain and depressive symptoms),
while the cardiovascular and fitness effects might require
long-term practices. In fact, some pain studies suggest that
short-term interventions might be more effective than longer
durations of practice [20]. This would indicate a putative
lack of motivation to be physically active. Indeed, a couple
of reviews noted that data on subject treatment compliance
was not routinely reported in most studies [4,30].
Clearly yoga intervention programs require an active
participation of the individuals as do all behavioral inter-
ventions, and thus adherence might be a crucial point that
limits potentially beneficial effectsofyoga.Itisapparentin
many life style diseases, that patients must change attitudes
and behaviour in order to successfully treat these diseases. A
positive feature of yoga interventions is that they may in fact
6 Evidence-Based Complementary and Alternative Medicine
Tab le 2: Level of action and observed effects of yoga interventions.
Specific effects Unspecific effects
Cognition Contemplative states; Mindfulness; Self-identity;
Self-efficacy; Beliefs; Expectations Control of attentional networks
Emotions Emotional control/regulation Quality of Life
Physiology Vaga l afferent activity; Heart rate/Respiratory; Relaxation
response/Stress reduction Social contacts
Physical body Physical flexibility, Fitness/Endurance Healthy life style
Specific and unspecific effects are often interconnected.
be very supportive for the execution and maintenance of such
lifestyle changes due to the experience of well-being from the
practices which can support regular practice, and from the
changes in mind/body awareness that occur over time with
continued yoga practice, which will in turn support a desire
to adopt and maintain healthy behaviours.
Thus, further studies should identify which patients may
benefit from the interventions, and which aspects of the yoga
interventions (i.e., physical activity and/or meditation and
subsequent life style modification) or which specific yoga
styles were more effective than others. Larger-scale and more
rigorous research is highly encouraged because yoga may
have potential to be implemented as a safe and beneficial
supportive/adjunct treatment that is relatively cost-effective,
may be practiced at least in part as a self-care behavioral
treatment, provides a life-long behavioural skill, enhances
self-efficacy and self-confidence, and is often associated with
additional positive side effects (Tabl e 2).
The degree to which yoga interventions are curative
treatments remains to be determined; currently it is safe to
suggest that yoga can be a beneficial supportive add-on or
adjunct treatment. Jayasinghe stated that one may “conclude
that yoga can be beneficial in the primary and secondary pre-
vention of cardiovascular disease and that it can play a pri-
mary or a complementary role in this regard” [38]. Because
of yoga’s low risk for side effects, when selecting appropriate
postures for the population, and potential for actual positive
side effects, it might be a promising candidate particularly
for cardiac rehabilitation, depending on the patients’ abilities
and willingness to adopt yoga practices with regularity. How-
ever, the meditative and self-reflective (cognitive) aspects
of yoga could be problematic especially for patients with
psychotic or personality disorders. Nevertheless, there is cur-
rently insufficient data on contraindications or side effects
related to yoga practices in patients with psychological dis-
orders.
Taken together, while several reviews suggest positive
benefits of yoga, various methodological limitations (includ-
ing small sample sizes, heterogeneity of controls and inter-
ventions) limit the generalizability of these promising study
findings. It is quite likely that yoga may help to improve
patient self-efficacy, self-competence, physical fitness, and
group support, and may well be effective as a supportive
adjunct to mitigate medical conditions, but not yet as a
proven stand-alone, curative treatment. Confirmatory stud-
ies with higher methodological quality and adequate control
interventions are needed.
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