Health and therapeutic benefits of Shatkarma: A narrative review of Scientific studies

Abstract

Shatkarma, also known as Shatkriya are a set of six yogic cleansing techniques described in the Hatha Yoga texts. Several health benefits of these procedures are indicated in the traditional texts of Yoga. However, there is no comprehensive literature about the scientific evidence on Shatkriya. Hence, we searched in PubMed, PubMed Central and Google Scholar databases to review relevant articles in English. The search yielded a total 723 references, published from 1976 to April 2020. Based on the inclusion and exclusion criteria, 37 articles were included in this review. We found scientific studies on four out of six cleansing techniques. The limited evidence on Shatkriya suggests positive effects on various physiological and clinical domains. The practice of dhauti was found to enhance respiratory functions and was useful in digestive disorders. Nasal cleansing, neti was particularly found beneficial in managing the rhinosinusitis in age groups ranging from children to adults. Although trataka practice was found to enhance cognition and bring a state of relaxation, but there was no evidence supporting its role in eye disorders. Kapalabhati practice appears to have a beneficial role in the activation of sympathetic nervous system, enhance cognition, and improve overall metabolism. Further large-scale clinical trials with robust designs are warranted to evaluate the effects of Shatkriya in health and disease.

Full text

Review Article
Health and therapeutic benefits of Shatkarma: A narrative review of
scientific studies
P.S. Swathi
*
, B.R. Raghavendra, Apar Avinash Saoji
Division of Yoga and Life Sciences, Swami Vivekananda Yoga Anusandhana Samsthana (S-VYASA), 19, Eknath Bhavan, Gavipuram Circle, KG Nagar,
Bengaluru, 560019, India
article info
Article history:
Received 7 May 2020
Received in revised form
20 October 2020
Accepted 24 November 2020
Available online xxx
Keywords:
Shatkarma
Shatkriya
Yoga
Yogic cleansing technique
Physiological effects
abstract
Shatkarma, also known as Shatkriya are a set of six yogic cleansing techniques described in the Hatha
Yog a texts. Several health benefits of these procedures are indicated in the traditional texts of Yoga.
However, there is no comprehensive literature about the scientific evidence on Shatkriya. Hence, we
searched in PubMed, PubMed Central and Google Scholar databases to review relevant articles in English.
The search yielded a total 723 references, published from 1976 to April 2020. Based on the inclusion and
exclusion criteria, 37 articles were included in this review. We found scientific studies on four out of six
cleansing techniques. The limited evidence on Shatkriya suggests positive effects on various physiological
and clinical domains. The practice of dhauti was found to enhance respiratory functions and was useful in
digestive disorders. Nasal cleansing, neti was particularly found beneficial in managing the rhinosinusitis
in age groups ranging from children to adults. Although trataka practice was found to enhance cognition
and bring a state of relaxation, but there was no evidence supporting its role in eye disorders. Kapalabhati
practice appears to have a beneficial role in the activation of sympathetic nervous system, enhance
cognition, and improve overall metabolism. Further large-scale clinical trials with robust designs are
warranted to evaluate the effects of Shatkriya in health and disease.
©2020 The Authors. Published by Elsevier B.V. on behalf of Institute of Transdisciplinary Health Sciences
and Technology and World Ayurveda Foundation. This is an open access article under the CC BY-NC-ND
license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
1. Introduction
Cleansing practices are part of most indegenous health systems,
be it Yoga, Naturopathy, Ayurveda, or Chinese Medicine. In Yoga, six
cleansing practices are described in the Hatha Yoga tradition, which
are known to balance the constitution of an individual. These six
cleansing practices in Yoga are known as Shatkarma or Shatkriya,
which are said to promote health and well-being by purifying the
whole body. Hatha Yoga Pradipika (ch: 2, v. 21 and 22) of Swat-
marama recommends the practice Shatkriya prior to practice of
pranayama (yogic breath regulation). The Shatkriya techniques
include dhauti (internal cleansing), basti (yogic enema), neti (nasal
cleansing), trataka (concentrated gazing), nauli (abdominal
massaging) and kapalabhati (frontal sinus cleansing) [1]. Although
several health benefits of Shatkriya are narrated in HathaYoga texts,
there is a lack of comprehensive literature on scientific studies in
the subject matter. Thus, the current review was undertaken to
summarize the scientific evidence on the physiological and thera-
peutic effects of the Shatkriya.
1.1. Traditional references for Shatkriya
There are four major texts of Hatha Yoga tradition viz. Hatha
Yoga Pradipika,Gheranda Samhita,Shiva Samhita and Hathar-
atnavali. Among them Gheranda samhita and Hatha Yoga Pradipika
describe the purification of the body, with reference to six variants
of the cleansing procedures [1,2]. Gheranda Samhita has an elabo-
rate description of the sub-types and benefits of the Shatkriya.
Hatharatnavali, which is the latest among the Hatha Yoga texts,
narrates eight variants of cleansing techniques [3]. However, the six
cleansing techniques described in the Hatha Yoga Pradipika of
Swami Swatmarama are most popular among the Yoga practi-
tioners. The main objective of Shatkriya is to balance the three
humours (tridosha) in the body, mucus (kapha), bile (pitta) and
wind (vata)[1].
*Corresponding author.
E-mail: swathisanketh@gmail.com (P.S. Swathi).
Peer review under responsibility of Transdisciplinary University, Bangalore.
Contents lists available at ScienceDirect
Journal of Ayurveda and Integrative Medicine
journal homepage: http://elsevier.com/locate/jaim
https://doi.org/10.1016/j.jaim.2020.11.008
0975-9476/©2020 The Authors. Published by Elsevier B.V. on behalf of Institute of Transdisciplinary Health Sciences and Technology and World Ayurveda Foundation. This is
an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Journal of Ayurveda and Integrative Medicine xxx (xxxx) xxx
Please cite this article as: P.S. Swathi, B.R. Raghavendra and A.A. Saoji, Health and therapeutic benefits of Shatkarma: A narrative review of
scientific studies, J Ayurveda Integr Med, https://doi.org/10.1016/j.jaim.2020.11.008

Though there are a few similarities in the cleansing procedures
described in Yoga and Ayurveda (such as basti and vamana dhauti),
the yogic cleansing methods are unique for multiple reasons. The
yogic cleansing is done by the practitioner himself under the
guidance of Yoga teacher and without administration of any
medicine.
2. Methodology
A comprehensive literature search in PubMed, PubMed Central,
and Google Scholar databases was carried out for the keywords
“shatkriya,shatkarma,dhauti. yogic stomach wash, basti, yogic
enema, neti, yogic nasal cleansing, nasal irrigation, trataka, yogic
visual concentration, nauli, yogic abdominal massage, kapalabhati,
yogic frontal sinus cleansing, high frequency Yoga breathing”. The
search yielded a total number of 665 references from the year 1976
till April 2020 for the above-mentioned keywords. Experimental
and quasi-experimental studies and case reports in English, with
yogic cleansing techniques as an intervention were included in the
review. The studies that had combination of Yoga practices were
excluded. After applying the inclusion and exclusion criteria and
removing the duplicates, a total of 37 studies were selected for the
final review. The studies are presented based on the cleansing
techniques.
3. Summary of scientific evidence on yogic cleansing
techniques
3.1. Dhauti
A literal meaning of dhauti is internal cleansing. Four major
forms of dhauti kriya as described in the Gheranda Samhita viz. antar
(internal), danta (teeth), hrid (cardiac) and moola shodhana (puri-
fication of the anus) [1,2]. The most popular forms of dhauti include
vamana dhauti, also known as kunjala kriya,vastra dhauti and
shankha prakshalana.Kunjala kriya includes drinking warm saline
water and voluntarily inducing vomiting to clear the contents of
stomach. In vastra dhauti, the practitioner swallows a soft cotton
cloth of about 2 m length and 4 cm width and removes the same.
The practice of shankha prakshalana includes drinking warm saline
water and passing it in the bowels by inducing peristalsis through
certain postures [1]. It aids in reducing ailments of the digestive
system like constipation, biliousness, indigestion, chronic gastritis,
reflux acts. It even helps to reduce accessory organ ailments of
digestive systems like torpid liver, sluggish pancreas, urinary
elimination, renal complaints, and dyspeptic condition. Indirectly it
strengthens the heart and respiratory systems like cough, asthma,
tonsillitis and teeth problems. It even benefits in arthritis, diabetes,
and loosening of weight [4].
3.1.1. Effects of dhauti on respiratory system
A study was conducted to assess the effect of kunjala kriya on the
pulmonary functions in healthy volunteers. The authors found the
practice to play a role in enhancing pulmonary functions along with
increased vagal tone. These findings were based on the increase in
slow vital capacity, forced inspiratory volume along with a reduc-
tion in expiratory reserve volume and respiratory rate. The findings
also indicate a possible increase in endurance of the respiratory
muscles, decreased airway resistance, better emptying of lungs,
which may play a role in restrictive lung disorders [5].
3.1.2. Effect of dhauti on bowel health
A recent randomized controlled study done on 60 healthy in-
dividuals, demonstrated beneficial effects of laghu shankha prak-
shalana in bowel health. Thirty volunteers who received the
intervention once in a week for 4 weeks demonstrated better scores
in the Cleveland clinic constipation scale. The control group
showed no significant change during the follow-up period [6].
3.1.3. Effect of dhauti in chronic low back pain
A self as controlled study was conducted in 40 in-patients,
randomly assigned to receive laghu shankha prakshalana and back
pain yogic special technique on specific days. Assessments were
performed before and immediately after the sessions. Pain and
disability were assessed using Oswestry disability index, state
anxiety using the state subscale of Spieldberger’s state and trait
anxiety inventory, spinal flexibility, and straight leg raising tests
using Leighton type goniometer and caliper type goniometer
respectively. Both Yoga sessions were found to beneficial to the
patients, but the magnitude of change was higher following the
laghu shankha prakshalana session. Thus, laghu shankha prak-
shalana practice was found to reduce pain, disability, anxiety, and
help to increase in flexibility [7].
3.1.4. A complication of dhauti
Practice of dhauti is generally considered safe when it is done
under the guidance of a teacher. One case study was found to report
the adverse effect of dhauti during the literature review. A case of
dental erosion diagnosed using the Tooth Wear Index was reported
by Meshramkar and Patil (2007) which they had attributed to the
regular practice of kunjala kriya for 12 years [8].
Thus, from the limited evidence available on dhauti kriya, it was
found useful as a therapeutic modality in the management of res-
piratory and digestive disorders. The practice should be done under
the guidance of a trained teacher, which may help to avoid possible
complications. Further large-scale clinical trials are required to
establish the usefulness of dhauti as therapeutic modality. We have
summarized the studies on dhauti in Table 1.
3.2. Neti (yogic nasal cleansing)
The practice of Neti is advised in Hatha Yoga to clean the nasal
passage. In classical reference of Hatha Yoga Pradipka only sutra neti
is explained however in general four variations of Neti practiced,
which includes jala (water), sutra (thread), dugdha (milk), and
ghritha (ghee) [1,9]. The most popular forms of Neti practice are jala
and sutra neti.InJala neti, saline warm water is passed from one
nostril to another using a specially designed pot. The classical
practice of sutra neti involves inserting a thread in the nostril and
removing it from the mouth. In modern times instead of thread, a
sterile catheter is used. Neti removes mucus from nostrils, sinuses
which helps to allow the air easily without obstruction. This help in
reducing allergic rhinitis, tonsillitis and to prevent cough, cold and
tension headache due to eye strain.
3.2.1. Use of Neti for rhino-sinusitis
A study done on 150 subjects with chronic sinusitis assigned
them in 3 treatment groups: nasal irrigation with a bulb syringe or
jala neti,orreflexology massage. The follow-up duration was for 2
weeks. All three groups demonstrated improvement in rhinosinu-
sitis outcome measures [10]. More than 70 percent of the partici-
pants wanted to continue practicing nasal irrigation even after
completion of the study. The study also depicted that the im-
provements in the symptoms were better in male population.
Smokers in the study did not show improvement in the symptoms.
Sinusitis is a common problem among children. Shoseyov et al.
(1998) conducted a double blind RCT to illustrate the efficacy of
normal water verses jala neti in children with chronic sinusitis. The
outcome measures used were cough, nasal secretion and radio-
logical assessment tools. They found significant improvements in
P.S. Swathi, B.R. Raghavendra and A.A. Saoji Journal of Ayurveda and Integrative Medicine xxx (xxxx) xxx
2

four-weeks in the group which used jala neti, when compared to
normal saline. The effects were sustained for a follow-up period of
one month after the conclusion of the trial [11].
A case series was conducted to report effects of jala neti in 10
cases of sinusitis among children (age range: 3e9 years). The au-
thors found improvement in the disease-related Quality of life and
in symptom management [12].
An early study assessed the inflammatory markers in thirty
symptomatic patients with active perennial allergic rhinitis. The
three interventions compared were nasal heated water particles at
43 degrees C for 20 min, heated molecular water vapor at 41

C for
20 min, and simple jala neti at 39

C solution for 15 min at weekly
intervals. Nasal washes were done before and immediately after the
treatments, at 30 min, 2 h, 4 h, 6 h. Inflammatory mediators such as
histamine, prostaglandin D2, leukotriene C4 concentrations were
assessed using a competitive radioimmunoassay. Inflammatory
mediators in nasal secretions decreased substantially after jala neti.
It reduced histamine for a period of 6 h, after a single 15 min
treatment, illustrating the beneficial effect of jala neti in reducing
allergic response and inflammation [13].
A study (SNIFS Trial) assessing the efficacy of self-management
tools for recurrent sinusitis compared jala neti with steam inhala-
tion. The investigators of the study followed 32 participants for a
period of six months. They concluded both interventions were
acceptable to the patients, but jala neti was found to be effective in
symptom management [14]. A large scale RCT involving 871 par-
ticipants indicated that jala neti being better in managing symp-
toms of rhino-sinusitis and being acceptable to participants than
steam inhalation [15].
A randomized control trial with seventy-six subjects followed
patients with sinusits for a period of six months. The investigators
found improved quality of life, reduced symptoms, and need for
medications in patients who performed jala neti daily for six-
months [16].
3.2.2. Neti for post-irradiation rhinosinusitis in nasopharyngeal
carcinoma
Sinusitis and nasopharyngeal irritation are common following
radiotherapy for nasopharyngeal carcinoma. A five-year follow-up
study demonstrated that long term nasal irrigation helped in
improving quality of life (QoL) of patients affected with nasopha-
ryngeal carcinoma within a one year of intervention there was a
relief in nasal symptoms [17]. Similar observation of improved
quality of life and reduced symptoms were observed in a trial
involving 107 nasopharyngeal carcinoma patients after irradiation.
The follow-up duration for the study was six months [18].
3.2.3. Complication of Sutra neti
There was a case of 67 year old man presenting with change of
voice, loss of sensation of smell, nose blockage and mouth
breathing after regular practice of Sutra neti. He had to undergo a
controlled ablation for release of the nostrils. The investigators
suggested to avoid vigorous practice of sutra neti [19].
Thus, Neti, being one of the easiest cleansing procedures in Yoga,
plays advantageous role in management of rhino-sinusitis. A case
study also indicates beneficial effect of sutra neti on obstructive
sleep apnea and snoring. The results indicate that the traditional
explanation from Hatha Yoga Pradipika stating neti can help to cure
disease above the throat appear to be supported with scientific
evidence. The evidence based effects of neti kriya are summarized
in Table 2.
3.3. Trataka (yogic visual concentration)
The practice of trataka involves concentrated gazing on a small
object (usually a candle flame). The classical explanation of the
practice involves gazing at an object without blinking the eyes, till
tears roll out. The technique is said to reduce the eye disorders and
to reduce the laziness [1]. The scientific studies on Trataka used
cognitive functions and vision as their outcome measures.
3.3.1. Effect of trataka on attention and cognition
A self as control study assessed effect of trataka on critical
flicker fusion (CFF). CFF is defined as the frequency at which a
flickering stimulus perceived to be continuous. Thirty subjects
were recruited for the study who were conditioned for the prac-
tice through five sessions on different days before the
commencement of assessments. Subjects were assessed individ-
ually for CFF immediately before and after the trataka or control
sessions. The trataka session involved eye exercise followed by
gazing at the candle flame whereas control session had only eye
exercise. The CFF was assessed with increasing and decreasing
frequencies. The trataka group shown a significant increase in CFF,
and there was a nonsignificant reduction in CFF following the
control session [21].
Another study with similar sample size (n ¼30) and design
evaluated the cognitive performance using the adult version of the
Stroop-color-word test. The results indicated improvement in
Table 1
Evidence summary on Dhauti.
Author Sample size Study type and Duration of
Intervention
Variables studied Findings
Kiran et al., 2019 [6] 60 (Experimental ¼30,
Control ¼30)
RCT
Once a week for 4 weeks for study
group &control group did not
receive intervention
Cleveland Clinic Constipation
Score
Four sessions of laghu shanka
prakshalana reduced constipation
score
Balakrishnan et al., 2018 [5] 18 (Experienced ¼9,
naïve ¼9)
Comparative Study between
naïve and experienced
practitioners.
Single session
Slow &forced vital capacity,
Inspiratory &expiratory reserve
volume, Respiratory rate &tidal
volume
Improved respiratory functions
were observed after Kunjal kriya
practice.
Haldavenkar et al., 2014 [7] 40 Self as control study
Single sessions of laghu shanka
prakshalana and back pain
specific yoga techniques were
compared after 3 days of training
Pain &disability, state anxiety,
spine flexibility and straight leg
raising
A single session of Laghu shanka
prakshalana was found better
than back pain specific yoga
session in reducing disability,
anxiety &improved spine
flexibility in patients with chronic
low back
Meshramkar et al., 2007 [8] 1 Single case report Tooth wear index of Smith &
Knight
The regular practice of kunjal
kriya for a prolonged time led to
dental erosion
P.S. Swathi, B.R. Raghavendra and A.A. Saoji Journal of Ayurveda and Integrative Medicine xxx (xxxx) xxx
3

selective attention, response inhibition, cognitive flexibility
following trataka session [22].
A randomized controlled trial done in elderly population evalu-
ated the effect of trataka on cognitive function. There was improve-
ment in the performance in the cognitive tasks such as digitspan, six-
letter cancellation test, and tail making test following a 26-day
intervention compared to the baseline. This study indicates a
possible role of trataka in preventing cognitive decline in elderly [23].
3.3.2. Effect of trataka in autonomic functions
A study assessed the immediate effect of trataka on heart rate
variability (HRV) and breathing rate following two sessions on two
different days. The investigators found an increased in vagal tone
following trataka depicted by a decrease in heart rate and breath
rate, low frequency component of HRV and increase in high fre-
quency component. No changes were observed following the con-
trol session [24].
3.3.3. Clinical trials on trataka and eye disorders
A study assessing outcomes of ametropia and presbyopia
compared the effects of two forms of eye exercises viz. Bates
method and trataka. The investigators reported subjective im-
provements in the vision without any change in objective assess-
ment tools following both forms of eye exercises [25,26]. Table 3
illustrates the studies on trataka. Although, traditional texts quote
trataka can be used to treat eye disorders, but not many studies
have evaluated the role of trataka in eye disorders. The limited
evidence does not support role of trataka in eye disorders, thus
there is scope for further scientific evaluation in the subject area
The studies also demonstrat enhanced cognitive functions and
autonomic relaxation immediately following the practice. Thus,
there is a need to explore long term effects of trataka in physio-
logical and clinical settings.
3.4. Kapalabhati (yogic frontal brain cleansing)
Kapalabhati is a combination of two syllables, kapala means
forehead and bhati means shining. The practice of kapalabhati
involves breathing out at a rapid pace (~1e2Hz)byflapping the
abdomen. Classical texts indicate beneficial role of Kapalabhati in
respiratory disorders [1] It is also known as high frequency Yoga
breathing due to the nature of practice. Generally the practice of
Table 2
Evidence summary of Neti.
Author Sample size Study type and duration of
Intervention
Variables studied Findings
Tiwana et al., 2019 [19] 1 Single case report Nasal endoscopy Vigorous practice of sutra neti
led to velopharyngeal stenosis
requiring surgical intervention.
Leydon et al., 2017 [14] 32 Qualitative semi-structured
interview study
Six months
Medication score, symptom
checklist
Neti was found better than
steam inhalation in reducing
symptoms of rhinosinusitis.
Little et al., 2016 [15] 871 (Usual care ¼210, Nasal
irrigation ¼219, Steam
inhalation ¼232,
Combined ¼210)
RCT
Six months
Rhinosinusitis Disability Index
(RSDI)
Neti was found better than
steam inhalation in reducing
symptoms of rhinosinusitis.
Lin et al., 2015 [12] 10 Pre and Post study
Daily for one month of nasal
irrigation
Sinus &Nasal Quality of Life
survey, Overall Nasal Quality of
Life
Neti helped to reduce chronic
nasal symptoms and improved
quality of life
Luo et al., 2014 [17] 1134 (GroupA ¼Nasal irrigator,
Group B ¼homemade nasal
irrigation connector combined
with enemator, Group C used
nasal sprayer)
Follow up study
Five years
Sinus &Nasal Quality of Life
survey
Long term use of neti helped in
improvement of quality of life
in nasal sinusitis patients
Liang et al., 2008 [18] 107 (Nasal irrigation ¼44, Non
irrigation ¼63)
RCT
Once daily upto six months of
nasal irrigation
Questionnaire and radiological
assessment of rhinosinusitis
The 6 months of follow up study
of neti after radiotherapy, neti
seems to improve the quality of
life and symptoms.
Rabago et al., 2002 [16] 76 (Experimental ¼52,
Control ¼24)
RCT
Daily hypertonic saline nasal
irrigation upto six months and
control group didn’t receive
intervention
Medical outcome survey short
form, Rhinosinusitis Disability
Index, Single- Item- Sinus
Symptom Severity assessment
Neti helped in reduction of
symptoms and medication,
even improved in quality of life
in sinusitis patients.
Heatley et al., 2001 [10] 150 (Nasal irrigation with bulb
syringe ¼43, nasal irrigation
with irrigation pot ¼39, &
reflexology massage ¼46)
RCT
Each group underwent 2 weeks
of intervention
Rhinosinusitis outcome
measures, Daily medication use
Neti was found equally effective
for the management of
rhinosinusitis, when compared
with reflexology massage and
nasal irrigation using bulb
syringe.
Shoseyov et al., 1998 [11] 30 (Hypertonic saline ¼15,
Normal saline ¼15)
Randomized double blind study
Four weeks of hypertonic saline
and nasal saline
Radiology score &nasal
secretion, cough or postnasal
drip for rhinosinusitis
There was significant reduction
in nasal secretions, cough &
postnasal drip in hypertonic
solution group than neti group
Georgitis; 1994 [13] 30 Self as control study Nasal secretions - histamine,
prostaglandin D2, leukotriene
C4
Neti and large particle water
vapour reduced nasal
histamines &leukotriene C4
indicative of reduced nasal
inflammation.
Ramalingam and
Smith; 1990 [20]
1 Single case report Self-assessment of symptoms Practice of sutra neti helped
person to reduce snoring and
obstructive sleep apnea
P.S. Swathi, B.R. Raghavendra and A.A. Saoji Journal of Ayurveda and Integrative Medicine xxx (xxxx) xxx
4

Kapalabhati is done prior to practice of pranayama (yogic
breathing practices). Some masters categorize the practice of
kapalabhati as one of the pranayama itself. However, the practice
is classified as one of the Shatkriya as per the traditional Yo ga
texts [27].
3.4.1. Effect of kapalabhati on metabolism
One of the earliest studies on kapalabhati showed a decrease in
blood urea with an increase in creatinine and tyrosine following
one minute of practice in twelve healthy subjects. These changes
were attributed to a possible promotion of decarboxylation and
oxidation [28].
3.4.2. Effect of kapalabhati on respiratory and cardiovascular
changes
Stancak and colleagues conducted a group of experiments to
determine physiological changes associated with kapalabhati as
early as in 1991. Their experiments demonstrated reduction in
baroreflex sensitivity and vagal tone, associated with increase in
blood pressure and heart rate following kapalabhati. They could
also demonstrate slower brain waves in the EEG topography which
were attributed to the subjective relaxation in the participants
[29e31].
Series of studies were conducted by Telles et al. on the effects of
kapalabhati. They found kapalabhati improves cognitive perfor-
mance and attention assessed through event related potentials
[32], associated with decreased anxiety [33]. Similar positive out-
comes were found with motor performance [34] and finger dex-
terity [35] and spatial and working memory tasks [36] following
Kapalabhati. They also observed sympathetic arousal [37,38], and
metabolic activation [39], during kapalabhati however, the practice
does not cause increase in the prefrontal cerebral circulation [40].
A study conducted on effect of kapalabhati on cognitive func-
tions demonstrated improvements in the cognitive tasks [41].
Transcranial doppler was used to assess the cerebral blood flow
changes during practice of kapalabhati. There was a reduction noted
in the end diastolic velocity and mean flow velocity indicating a
decrease in cerebral blood flow. Such change could be due to
reduction of partial pressure of CO2 during the practice which in-
volves breathing at a high frequency [42].
An RCT performed on 60 mild to moderate asthma patients
demonstrated 10 min of practice of kapalabhati can enhance the
forced vital capacity, forced expiratory volume in one second and
their ratio. These finding indicate a possible role of kapalabhati in
management of bronchial asthma [43].
3.4.3. The complication of kapalabhati
A case report presented a 29-year-old healthy woman, who
developed the spontaneous pneumothorax caused due to extreme
practice of kapalabhati. The investigators attributed such compli-
cation to pushing the practice to physiological extreme limits [44].
Thus, the studies on kapalabhati illustrate the beneficial effects
of the technique in enhancing cognitive and respiratory functions
and leading to a state of physiological arousal. Such changes can be
used in clinical situations such as bronchial asthma. However, one
should be careful not to strain while performing the practice of
kapalabhati, which may also lead to complications. The evidence
summary on kapalabhati is summarized in Table 4.
3.5. Basti (yogic enema)
There are two forms of Basti described in Hatha Yoga,jala (wa-
ter) and sthala (dry). Both basti practices involve the cleansing of
the colon. Swami Swatmarama considers the practice of basti
beneficial for balancing tridosha and dhatus and to purify mind and
senses [1]. According to sage Gherenda,basti reduces the disorders
of vata and is beneficial in urinary and digestive problems. It is also
known to improve digestion [2].
Table 3
Evidence summary of Trataka.
Author &Year Sample size Study type and duration of
Intervention
Variables studied Findings
Tiwari et al., 2018 [26]48
(Trataka yoga
kriya ¼24, Eye
exercise ¼24)
Comparative study
Eight weeks of either trataka or
eye exercise group
Snellen’s Chart Trataka and eye exercise did not
show any significant changes in
refractive errors
Raghavendra and Singh;
2016 [22]
30 Self as control study
After 15 days of orientation
programme in trataka,
immediate effect of 25 min
assessed for trataka &control
session
Stroop colour-word test Improvement in selective
attention, cognitive flexibility,
and response inhibition was
found following trataka session
Talwadkar et al., 2014 [23]60
(Trataka group ¼36,
control group ¼24)
RCT
One month (26 days) of trataka
or control group
Digit span test, six letter
cancellation test, trail making
test
Trataka session in elderly
population shown significant
increase in cognitive levels
compare to control group
Raghavendra and
Ramamurthy; 2014 [24]
30 Self as control study
After 15 days of orientation
programme in trataka,
immediate effect of 25 min
assessed for trataka &control
session
Heart rate variability (HRV) &
respiration rate
Trataka group shown decrease
in heart rate, breath rate, low
frequency component of HRV
and increase in high frequency
component of HRV
Gopinathan et al., 2012 [25]66
(Eye exercise ¼32,
trataka yoga kriya ¼34)
RCT
Once daily for three weeks of
eye exercise or trataka
Signs and symptoms of
presbyopia, retinoscopy,
autorefractometer, keratometer
Both Trataka and eye exercise
improve subjective signs and
symptoms, but no change in
both groups on objective
assessments
Mallick and Kulkarni; 2010
[21]
30 Self as control study
Five practice session of trataka
(30 min) introduced before the
immediate assessment.
Critical Flicker fusion After the practice of trataka
there was a significant increase
in critical flicker fusion
compare to eye exercise group
P.S. Swathi, B.R. Raghavendra and A.A. Saoji Journal of Ayurveda and Integrative Medicine xxx (xxxx) xxx
5

Table 4
Evidence summary of Kapalabhati.
Author &Year Sample size Study type and duration of
Intervention
Variables studied Findings
Gupta et al., 2019 [36] 15 Repeated measures study
Single session of 18 min assessed
for kapalabhati and breath
awareness on two separate days
and control group were sitting at
ease
Corsi block-tapping task Improvement in memory scores
following breath awareness,
kapalabhati did not show any
significant changes
Telles et al., 2019 [33] 61 Repeated measures study
Single session of 18 min assessed
for kapalabhati and breath
awareness on two separate days
and control group were sitting at
ease
Six letter cancelation task &
Spielberger’s State Trait Anxiety
Inventory eS
Kapalabhati practice increased
attention with reduction in
anxiety levels
Nivethitha et al., 2018 [42] 18 Repeated measures study
Single session on three- different
yogic techniques were performed
for different duration
Cerebrovascular haemodynamic
changes using Transcranial
doppler
During practice of 1 min of
kapalabhati, decreased cerebral
blood flow was noted
Raghavendra
et al., 2016 [43]
60 (Kapalabhati ¼30
and Deep
breathing ¼30)
RCT
Single session of 10 min for each
group
Pulmonary functions using
Spirometry
Practice of kapalabhati enhanced
forced vital capacity, forced
expiratory volume and thier ratio
in asthma patients
Telles et al., 2016 [40] 40 (Experimental ¼20,
and Control ¼20)
Two group-controlled trial
Single session of 18 min assessed
for kapalabhati and breath
awareness on two separate days
and control group were sitting at
ease
Haemodynamic changes -
functional near-infrared
spectroscopy
Practice of kapalabhati does not
cause increase in the prefrontal
cerebral circulation
Telles et al., 2015 [39] 67 (Experimental ¼47,
and Control ¼20)
RCT
Single session of 18 min assessed
for kapalabhati and breath
awareness on two separate days
and control group were sitting at
ease
Metabolic &ventilatory changes -
open circuit oxygen consumption
analyser
Metabolic activation was
observed after the practice of
kapalabhati
Telles et al., 2014 [34] 50 Repeated measures study
Single session of 15 min assessed
for kapalabhati and breath
awareness on two separate days
Hand grip strength and Motor
speed
Breath awareness and kapalabhati
improved arm &finger tapping,
kapalabhati alone enhanced hand
grip strength
Balaram; 2013 [41] 36 Repeated measures study
Comparison made between
Single sessions of kapalabhati for
1 and 5-min on two separate days
Six letter cancellation task and
digit letter substitution task
The practice of kapalabhati did
not show any significant changes
in performance in the six-letter
cancellation task and digit letter
substitution task
Telles et al., 2012 [35] 94 (Kapalabhati ¼47,
breath awareness ¼47)
RCT
Single session of 10 min
kapalabhati and breath awareness
for same period
Finger Dexterity and Visual
discrimination
Improvement in finger dexterity
and visual discrimination
following kapalabhati when
compared to breath awareness
Telles et al., 2011 [38] 38 Self as Control Study
Single session of 15 min of
kapalabhati and breath awareness
on alternate days
Heart rate variability The practice of kapalabhati shown
a reduction in parasympathetic
modulation and increased
sympathetic arousal
Joshi et al., 2009 [32]30(Kapalabhati ¼15,
and breath
awareness ¼15)
Comparative study
Single session of 1 min for each
group
Cognition &attention - P300
event-related potentials
Kapalabhati and breath
awareness, both practices shown
improvement in selective
attention assessed through P300
Jhonson et al., 2004 [44] 1 Single case report Chest radiograph The case of spontaneous
pneumothorax was reported after
the practice of kapalabhati
Raghuraj et al., 1998 [37] 12 Self as Control Study
Single session
Heart rate variability Kapalabhati practice shown an
increase in low frequency power,
LF/HF ratio and a decrease in high
frequency power signifying
increased sympathetic activity
Stanc
ak et al., 1991 [31] 17 Pre-Post Study
Single session of 5 min of
kapalabhati
Cardiovascular and respiratory
changes
The practice of kapalabhati shown
a reduction in baroreflex
sensitivity and vagal tone,
associated with an increase in
blood pressure and heart rate.
Stanc
ak et al., 1991 [30] 11 Pre-Post Study
Single session of 20 min of
kapalabhati
Electrical activity of the brain -
EEG topography
During the practice of kapalabhati
initial 10 min, there was an
increase in alpha and beta waves,
in the last 15 min, there was an
increase in theta waves and
maintained during the resting
period after kapalabhati.
P.S. Swathi, B.R. Raghavendra and A.A. Saoji Journal of Ayurveda and Integrative Medicine xxx (xxxx) xxx
6

3.6. Nauli (yogic abdominal massaging)
Nauli is a practice of contracting and isolating the rectus
abdominis muscle and churning the abdominal muscles. There are
three variations based on the position of isolation of the muscles,
namely dakshina nauli (right), vama nauli (left), madhyama (center).
This practice is said to strengthen the secretion of gastric juice
including endocrine and exocrine functions of the pancreas [1,9].
Since the practices of basti and nauli are considered to be an
advance practice, we could not find any scientific study on the
practice of nauli during our literature review.
4. Conclusion
The practice of shatkriya or shatkarma is recommended in the
Hathayoga tradition. Studies exploring the effects of four out of six
cleansing procedures were found in physiological as well as clinical
settings. No studies were available on basti and nauli which could
be due to the difficult nature of the practice. The practice of dhauti
was found to enhance respiratory functions and was useful in
digestive disorders. Nasal cleansing, neti was particularly found
beneficial in managing the rhinosinusitis in age groups ranging
from children to adults. Although trataka practice was found to
enhance cognition and bring a state of relaxation, but there was no
evidence supporting its role in eye disorders. Kapalabhati was the
most studies among the Shatkriya practices. The ranges of studies
on kapalabhati included assessing the neurocognitive assessments,
autonomic, and metabolic activity. The practice appears to have a
beneficial role in the activation of sympathetic nervous system,
enhances cognition, and improves overall metabolism. It was also
found to enhance the respiratory functions in patients with asthma.
Single case reports (one each) were also found for practices of
dhauti, neti and kapalabhati and it was attributed to pushing the
body to the physiological extreme.
This literature review was limited to online free databases only
and due to the keywords chosen. Although we tried, including a
variety of key-words related to shatkriya, there may have been
studies that were missed in the current review because of exclusion
through the keywords and databases.
The beneficial role of shatkriyas narrated in both traditional texts
and evident from the small body of empirical work warrants
further rigorous scientific exploration. From the available literature,
we found the practice of yogic cleansing technique safe, when
practiced under the guidance of a trained teacher and has a po-
tential role in health and disease.
Sources of Funding
None.
Conflict of interest
None.
References
[1] Muktibodhananda S. Hatha yoga Pradipika. Munger: Yoga Publications trust;
1999.
[2] Saraswati SN. Gheranda samhita -: commentary on the yoga teachings of
maharshi Gheranda. Munger: Yoga Publications trust; 2012.
[3] Gharote M, Parimal D. Hatharatnavali (A treatise on Hathayoga of sriniva-
sayogi). Motilal Banarsidass; 2003.
[4] Yogeshwar G. Kunjara - the yogic stomach wash. Ancient Sci Life 1992;12:
261e3.
[5] Balakrishnan R, Nanjundaiah RM, Manjunath NK. Voluntarilyinduced vomiting -
a yoga technique to enhancepulmonary functionsin healthy humans. J Ayurveda
Integr Med 2018;9:213e6. https://doi.org/10.1016/j.jaim.2017.07.001.
[6] Kiran S, Sapkota S, Shetty P, Honnegowda T. Effect of yogic colon cleansing
(laghu sankhaprakshalana kriya) on bowel health in normal individuals. Yoga
Mimamsa 2019;51:26. https://doi.org/10.4103/ym.ym_4_19.
[7] Tekur P, Nagarathna R, Nagendra H, Haldavnekar R. Effect of yogic colon
cleansing (Laghu Sankhaprakshalana Kriya) on pain, spinal flexibility,
disability and state anxiety in chronic low back pain. Int J Yoga 2014;7:111.
https://doi.org/10.4103/0973-6131.133884.
[8] Meshramkar R, Patil SB, Patil NP. A case report of patient practising yoga
leading to dental erosion. Int Dent J 2007;57:184e6. https://doi.org/10.1111/
j.1875-595X.2007.tb00123.x.
[9] Patra S. Physiological effect of kriyas: cleansing techniques. Int J Yoga - Philos
Psychol Parapsychol 2017;5:3. https://doi.org/10.4103/ijny.ijoyppp_31_17.
[10] Heatley DG, McConnell KE, Kille TL, Leverson GE. Nasal irrigation for the
alleviation of sinonasal symptoms. Otolaryngol Head Neck Surg 2001;125:
44e8. https://doi.org/10.1067/mhn.2001.115909.
[11] Shoseyov D, Bibi H, Shai P, Shoseyov N, Shazberg G, Hurvitz H. Treatment with
hypertonic saline versus normal saline nasal wash of pediatric chronic
sinusitis. J Allergy Clin Immunol 1998;101:602e5. https://doi.org/10.1016/
S0091-6749(98)70166-6.
[12] Lin SY, Baugher KM, Brown DJ, Ishman SL. Effects of nasal saline lavage on
pediatric sinusitis symptoms and disease-specific quality of life: a case series
of 10 patients. Ear Nose Throat J 2015;94:E13. https://doi.org/10.1177/
014556131509400212.
[13] Georgitis JW. Nasal hyperthermia and simple irrigation for perennial rhinitis:
changes in inflammatory mediators. Chest 1994;106:1487e92. https://
doi.org/10.1378/chest.106.5.1487.
[14] Leydo n GM, McDermott L, Thomas T, Halls A , Holdstock-B rown B,
Petley S, et al. “Well, it literally stops me from having a life when it’s
really bad”: a nested qualitative interview study of patient views on the
use of self-management treatments for the management of recurrent
sinusitis ( SNIFS trial) . BMJ Open 2017; 7. https://doi.org/10.1136/bmjopen-
2017-017130.
[15] Littl e P, Mullee M, Stu art B, Thomas T, Johnson S, Leydo n G, et al. Effec-
tiveness of steam inhalation and nasal irrigation for chronic or recurrent
sinus symptoms in primary care: a pragmatic randomized controlled trial.
CMAJ (Can Med A ssoc J) 2016;1 88:940e9. https://doi.org /10.1503/
cmaj.160362.
[16] Rabago D, Zgierska A, Mundt M, Barrett B, Bobula J, Maberry R. Efficacy of
daily hypertonic saline nasal irrigation among patients with sinusitis: a ran-
domized controlled trial. J Fam Pract 2002;51:1049e55.
[17] Luo HH, Fu ZC, Cheng HH, Liao SG, Li DS, Cheng LP. Clinical observation and
quality of life in terms of nasal sinusitis after radiotherapy for nasopharyngeal
carcinoma: long-term results from different nasal irrigation techniques. Br J
Radiol 2014;87. https://doi.org/10.1259/bjr.20140043.
[18] Liang K-L, Kao T-C, Lin J-C, Tseng H-C, Su M-C, Hsin C-H, et al. Nasal irrigation
reduces postirradiation rhinosinusitis in patients with nasopharyngeal carci-
noma. Am J Rhinol 2008;22:258e62. https://doi.org/10.2500/ajr.2008.22.3166.
[19] Tiwana H, Virk RS, Gautam V. The ancient practice of sutra neti leading to
velopharyngeal stenosis: case report. J Laryngol Otol 2019;133:730e2.
https://doi.org/10.1017/S0022215119001142.
[20] Ramalingam KK, Smith MCF. Simple treatment for snoring also a means of
prediction of uvulopalatopharyngoplasty success? J Laryngol Otol 1990;104:
428e9. https://doi.org/10.1017/S0022215100158633.
[21] Mallick T, Kulkarni R. The effect of trataka, a yogic visual concentration
practice, on critical flicker fusion. J Alternative Compl Med 2010;16:1265e7.
https://doi.org/10.1089/acm.2010.0012.
Table 4 (continued )
Author &Year Sample size Study type and duration of
Intervention
Variables studied Findings
Stanc
ak et al., 1991 [29] 24 Pre-Post Study
Single session of 15 min of
kapalabhati
Respiratory and cardiovascular
rhythmicity’s
Kapalabhati altered the
respiratory frequency and
increased blood pressure
Desai &Gharote; 1990 [28] 12 Details about the design of the
study are not available
Serum urea, creatinine, and
tyrosine
There was a significant reduction
in blood urea, increase in
creatinine, and tyrosine following
1 min kapalabhati
P.S. Swathi, B.R. Raghavendra and A.A. Saoji Journal of Ayurveda and Integrative Medicine xxx (xxxx) xxx
7

[22] Raghavendra BR, Singh P. Immediate effect of yogic visual concentration on
cognitive performance. J Tradit Complement Med 2016;6:34e6. https://
doi.org/10.1016/j.jtcme.2014.11.030.
[23] Talwadkar S, Jagannathan A, Raghuram N. Effect of trataka on cognitive
functions in the elderly. Int J Yoga 2014;7:96e103. https://doi.org/10.4103/
0973-6131.133872.
[24] Raghavendra B, Ramamurthy V. Changes in heart rate variability following
yogic visual concentration (Trataka). Hear India 2014;2:15. https://doi.org/
10.4103/2321-449X.127975.
[25] Gopinathan G, Dhiman KS, Manjusha R. A clinical study to evaluate the effi-
cacy of Trataka Yoga Kriya and eye exercises (non-pharmacological methods)
in the management of Timira (Ammetropia and Presbyopia). Ayu 2012;33:
543e6. https://doi.org/10.4103/0974-8520.110534.
[26] Tiwari KK, Shaik R, Aparna B, Brundavanam R. A comparative study on the
effects of vintage nonpharmacological techniques in reducing myopia (bates
eye exercise therapy vs. Trataka yoga kriya). Int J Yoga 2018;11:72e6. https://
doi.org/10.4103/ijoy.IJOY_59_16.
[27] Saoji AA, Raghavendra BR, Manjunath NK. Effects of yogic breath regulation: a
narrative review of scientific evidence. J Ayurveda Integr Med 2019;10:50e8.
https://doi.org/10.1016/j.jaim.2017.07.008.
[28] Desai BP, Gharote ML. Effect of Kapalabhati on blood urea, creatinine and
tyrosine. Act Nerv Super (Praha) 1990;32:95e8.
[29] Stanc
ak A, Kuna M, Nov
ak P, Srinivasan MA, Dost
alek C, Vishnudevananda S.
Observations on respiratory and cardiovascular rhythmicities during yogic
high-frequency respiration. Physiol Res 1991;40:345e54.
[30] Stanc
ak A, Kuna M, Srinivasan, Dost
alek C, Vishnudevananda S. Kapalabhati–
yogic cleansing exercise. II. EEG topography analysis. Homeost Health &Dis
1991;33:182e9.
[31] Stanc
ak A, Kuna M, Srinivasan, Vishnudevananda S, Dost
alek C. Kapalabhati–
yogic cleansing exercise. I. Cardiovascular and respiratory changes. Homeost
Health &Dis 1991;33:126e34.
[32] Joshi M, Telles S. A nonrandomized non-naive comparative study of the effects
of kapalabhati and breath awareness on event-related potentials in trained
yoga practitioners. J Alternative Compl Med 2009;15:281e5. https://doi.org/
10.1089/acm.2008.0250.
[33] Telles S, Gupta RK, Gandharva K, Vishwakarma B, Kala N, Balkrishna A. Im-
mediate effect of a yoga breathing practice on attention and anxiety in pre-
teen children. Child (Basel, Switzerland) 2019;6:84. https://doi.org/10.3390/
children6070084.
[34] Telles S, Sharma SK, Yadav A, Singh N, Balkrishna A. Immediate changes in
muscle strength and motor speed following yoga breathing. Indian J Physiol
Pharmacol 2014;58:22e9.
[35] Telles S, Singh N, Balkrishna A. Finger dexterity and visual discrimination
following two yoga breathing practices. Int J Yoga 2012;5:37e41. https://
doi.org/10.4103/0973-6131.91710.
[36] Gupta R, Agnihotri S, Telles S, Balkrishna A. Performance in a Corsi block-
tapping task following high-frequency yoga breathing or breath awareness.
Int J Yoga 2019;12:247. https://doi.org/10.4103/ijoy.ijoy_55_18.
[37] Raghuraj P, Ramakrishnan AG, Nagendra HR, Telles S. Effect of two selected
yogic breathing techniques on heart rate variability. Indian J Physiol Phar-
macol 1998;42:467e72.
[38] Telles S, Singh N, Balkrishna A. Heart rate variability changes during high
frequency yoga breathing and breath awareness. Biopsychosoc Med 2011;5:4.
https://doi.org/10.1186/1751-0759-5-4.
[39] Telles S, Singh N, Balkrishna A. Metabolic and ventilatory changes during and
after high-frequency yoga breathing. Med Sci Monit Basic Res 2015;21:
161e71. https://doi.org/10.12659/MSMBR.894945.
[40] Telles S, Gupta RK, Singh N, Balkrishna A. A functional near-infrared spec-
troscopy study of high-frequency yoga breathing compared to breath
awareness. Med Sci Monit Basic Res 2016;22:58e66. https://doi.org/
10.12659/MSMBR.899516.
[41] Pradhan B. Effect of kapalabhati on performance of six-letter cancellation and
digit letter substitution task in adults. Int J Yoga 2013;6:128e30. https://
doi.org/10.4103/0973-6131.113415.
[42] Nive thitha L, Mooventhan A, Manju nath NK, Bathal a L, Sharma VK. Ce-
rebrovascular hemodynamics during the practice of bhramari pranayama,
kapalbhati and bahir-kumbhaka: an exploratory study. Appl Psychophy-
siol Biofee dback 2018;43 :87e92. https://doi.org/10.1007/s10484-017-
9387-8.
[43] Raghavendra P, Shetty P, Shetty S, Manjunath NK, Saoji AA. Effect of high-
frequency yoga breathing on pulmonary functions in patients with asthma:
a randomized clinical trial. Ann Allergy Asthma Immunol 2016;117:550e1.
https://doi.org/10.1016/j.anai.2016.08.009.
[44] Johnson DB, Tierney MJ, Sadighi PJ. Kapalabhati pranayama: breath of fire or
cause of pneumothorax? A case report. Chest 2004;125:1951e2. https://
doi.org/10.1378/chest.125.5.1951.
P.S. Swathi, B.R. Raghavendra and A.A. Saoji Journal of Ayurveda and Integrative Medicine xxx (xxxx) xxx
8