Medical Research

The medical community generates a great deal of scientific research on the benefits of therapeutic yoga and meditation. We encourage you to explore and learn more from the sample of studies below

Summaries by Katrin L Ramsey, PT, DSc

Yoga for Cancer Survivorship

Littman AJ, Bertram LC, Ceballos R, et al. Randomized controlled pilot trial of yoga in overweight and obese breast cancer survivors: effects on quality of life and anthropometric measures. Support Care Cancer. 2012; 20:267‒77.

This study of n=63 borderline and overweight stage 0-III breast cancer survivors compared a 6 month facility and home based yoga practice group with a wait list control group.  The yoga group participated in a mean of 19.6 facility based classes and a mean of 55.8 home yoga sessions during the study.  The results of the study showed that the waist circumference decreased more among the yoga participants than the control group.  Both groups showed improvement trends in quality of life measures (although there was no statistically significant difference between groups).  The results of this study suggest that yoga may help improve the health of breast cancer survivors by facilitating improved quality of life as well as decreased anthropometric measures.

Bower JE, Garet D, Sternlieb B, et al.  Yoga for persistent fatigue in breast cancer survivors: a randomized controlled clinical trial. Cancer. 2012; 118(15):3766‒75. 

This study involved N=31 stage 0-2 breast cancer survivors reporting significant cancer fatigue (score of 50 or below on the SF-36 vitality scale) after completion of oncology treatment.  It compared 12 week treatment interventions of Iyengar-based yoga versus health education/instruction (control). Yoga participants attendedtwice weekly 90 minute yoga classes with 80% of the yoga participants completing at least 20/24 classes offered.  Health education participants attended once weekly psychologist taught 120 minute classes.  Post study completion, the yoga participants exhibited a significant decrease in fatigue severity and a significant increase in vigor when compared to the health education group.  Both groups exhibited positive changes in depression symptomology and perceived stress.  The results of this study indicate yoga interventions help minimize cancer related fatigue symptomology in breast cancer survivors and helped improve survivorship by minimizing depression and perceived stress levels.

Cohen CH, Warneke C, Fouladi RT, et al. Psychological adjustment and sleep quality in a randomized trial off the effects of a Tibetan yoga intervention in patients with lymphoma. Cancer. 2004; 100(10):2253‒60. 

This study of n=30 lymphoma survivors compared a 7 week duration once weekly Tibetan yoga intervention group with a wait list control group.  Yoga participants exhibited significantly better overall sleep quality, fell asleep faster, used fewer sleep medications and slept longer durations than control group participants.  The results of this study suggest that cancer patients experiencing sleep disturbances might benefit from yoga participation to facilitate improved sleep patterns.

Vadiraja SH, Rao MR, Nagendra RH, et al. Effects of yoga on symptom management in breast cancer patients: a randomized controlled trial. Int J Yoga. 2009; 2(2):73‒9. 

This study of n=88 stage II and III breast cancer survivors compared the effects of an integrated 60 minute yoga program (20-24 sessions over 6 weeks) versus brief supportive therapy (15 minute social worker counseling for 3-4 sessions) upon the distressful side effects associated with oncology diagnosis and radiotherapy treatments.   Yoga participants exhibited decreased psychological distress, decreased physical distress, decreased fatigue, and decreased insomnia after study completion when compared to supportive therapy controls.  Yoga participants additionally exhibited a significant increase in activity levels after the study when compared to supportive therapy controls.  The results of this study suggest that yoga might assist breast cancer survivors in more effectively managing cancer and treatment related symptoms like fatigue, nausea and vomiting, pain, inability to sleep, appetite loss and difficulty breathing.  Effectively managing symptoms may help survivors minimize cancer related fatigue and facilitate improved function via increasing survivor physical activity levels.

Danhauer SC, Mihalko SL, Russell GB, et al. Restorative yoga for women with breast cancer: findings from a randomized pilot study. Psycho-Oncology. 2009 April; 18(4):360‒8. 

This study examined the effects of a restorative yoga program (10 weekly 75 minute classes) upon n=44 breast cancer survivors.  Subjects were divided into yoga or waitlist control groups.  Yoga participants attended a mean of 5.8 classes during study participation.  Yoga participants exhibited greater improvements in mental health, depression, positive affect and spirituality (peace/meaning) than the waitlist control group post study.  The results of this study suggest that restorative yoga improves the emotional and psychological health of breast cancer survivors.

Raghavendra RM, Nagarathna HR, Gopinath KS, et al. Effects an integrated yoga program on chemotherapy induced nausea and emesis in breast cancer patients. Eur J Cancer Care (Eng). 2007; 16:462‒74.

This study of n=62 breast cancer survivors compared the effects of a supervised/home yoga intervention (60 minutes daily) to a supportive intervention while survivors were undergoing active chemotherapy treatment. Yoga participants exhibited a significant decrease in post chemotherapy induced nausea and nausea intensity than the supportive intervention group.  The results of this study suggest that yoga participation might be an effective method to manage chemotherapy induced nausea and vomiting.

Moadel AB, Shah C, Wylie-Rosett J, et al. Randomized controlled trial of yoga among a multiethnic sample of patients: effect upon quality of life. J Clin Oncol. 2007; 25:4387‒95. 

This large n=128 study of stage I-III breast cancer survivors examined the effects of twelve 1.5 hour weekly yoga interventions (based upon Hatha yoga techniques) upon multiple quality of life measures.  Subjects were divided into yoga participants and wait list control groups.  Results indicated that yoga participants exhibited less decline in social well-being than the control group in post study measures.  Although yoga did not improve the social well-being scores of yoga participants, it would appear that yoga participation provides valuable social support for breast cancer survivors.  Yoga participation appears to have a blunting effect upon the oncology treatment side effect of survivor social functioning decline.

Yoga for Treatment of Addictive Disorders

Shaffer HJ, LaSalvia TA, Stein JP: Comparing hatha yoga with dynamic group psychotherapy for enhancing methadone maintenance treatment: a randomized clinical trial. Alt Therapies Health Med. 1997; 3(4):57-66. 

This study involving n=61 male and female substance abusers compared a methadone maintenance treatment program enhanced by traditional group psychotherapy interventions to a methadone maintenance program enhanced by group hatha yoga participation.  Subjects in this study receiving daily methadone treatments participated in either weekly 75 minute sessions of group psychodynamic counseling (verbal)  or group hatha yoga (physical, non-verbal) exercise participation.  Entire study duration was 22 weeks with yoga intervention introduced @ the 15 week study mark (for a total of 7 weeks yoga instruction received by participants).  Primary psychological outcomes measures included the SCL-90 (Symptom Check List) and the ASI (Addiction Severity Index).  Neither group exhibited statistically significant changes in SCL-90 or ASI scores as a result of treatment.  However, BOTH psychodynamic counseling and hatha yoga participant groups exhibited significantly decreased drug use and criminal activities as a result of study participation.  The authors concluded that both yoga and psychodynamic therapy effectively complement a methadone maintenance program for drug addiction.

Yoga for Survivors of Domestic Violence

Franzblau SH, Echevarria S, Smith M, Van Cantfort TE.  A preliminary investigation of the effects of giving testimony and learning yoga breathing techniques in battered women’s feelings of depression. J Interpersonal Violence. 2008; 23: 1800-1808.

This preliminary study was composed of n=40 women self- identified as verbally, emotionally or sexually abused by a male with whom they had been intimate with over the previous 2 years.  Participants were randomly assigned to a testimony group, yogic breathing group, testimony combined with yogic breathing group, or control group.  Treatment interventions occurred over a 4 day time frame.  Yogic breathing interventions were 45 minutes duration and included instruction in extension/reduction of inhalation/exhalation, breath with sound for relaxation, and simple yoga poses incorporated with breathing to facilitate mind/body stillness.  Testimony intervention was also 45 minutes duration and allowed subjects to verbally report their abuse experience in a supportive setting.  Pre and post study data compared BDI-II (depression) score changes among participants.  Results:  the testimony group, the yogic breathing group, and the testimony/yogic breathing group all exhibited significant decreases in BDI-II scores as a result of treatment intervention.  The combination of verbal testimony combined with yogic breathing yielded the most powerful positive influence on depression scores of abused women.

Dale LP, Carroll LE, Galen GC, Schien R, Bliss A, Mattison AM, Neace WP. Yoga practice may buffer the deleterious effects of abuse on women’s self-concept and dysfunctional coping. J Aggression Maltreatment Trauma. 2011; 20:89-101. 

This study of n=51 women utilized a small sample group of highly educated women who were regular yoga participants at a yoga studio.  25% of the study participants reported a medical history that included a mental health diagnosis (depression, anxiety, seasonal affective disorder).  Study participants were divided between a child abuse group and adult abuse group.  The study did not have a control group.  Outcome measures included the YES (Yoga Experience Scale).  The findings of this study suggested that frequent practice of yoga might help women recover from abuse experiences via facilitation of improved coping skills and self-esteem.  Yoga experience (frequent yoga participation) enhanced the amount of positive mental health benefits reported by participants.  

Yoga for Youth with Special Needs

Chaya MS, Nagendra H, Selvam S, Kurpad A, Srinivasin K. Effect of yoga on cognitive abilities in schoolchildren from a socioeconomically disadvantaged background: a randomized controlled study. J Alt Compl Med. 2012; 8(12):1161-1167.

This study in India of n=180healthy socioeconomically disadvantaged children ages seven to nine divided subjects into either a physical activity or yoga intervention group.  Students participated in daily 45 minute sessions of physical activity or yoga for six days/week over a study duration period of 3 months.  Children in both groups exhibited a significant improvement in cognitive function measures of comprehension, arithmetic, vocabulary and object assembly as a result of study participation (measured at both 3 month and 6 month post study completion).  Students that participated in the yoga intervention appeared to exhibit significantly enhanced attention and visuo-spatial abilities post study participation.  The sustained positive effects of yoga participation upon the students observed in this study suggest that yoga interventions might be an effective method to enhance education and promote classroom behavior conducive to learning.

Steiner NJ, Sidhu TK, Pop PG, Frenette EC, Perrin EC. Yoga in an urban school for children with emotional and behavioral disorders: a feasibility study. J Child Fam Stud.; 2013:22:815-826.

This study of n=37 fourth and fifth graders with EBD (emotional and behavioral disorders like anxiety, depression, posttraumatic stress disorder and conduct disorder) occurred in an urban US elementary school setting.  Subjects participated in twice weekly yoga sessions in school for a study duration period of 3.5 months.   Outcomes measures included parental, student and teacher completed questionnaires.  Teacher assessment included BASC-2 (Behavior Assessment Scale for Children) and SKAMP (Swanson, Kotkin, Alger, M-Flynn and Pelham Rating scale).  Results:  Teachers reported that student yoga participants exhibited improved classroom attention and adaptive skills as a result of study involvement.  Educators also observed that yoga participants exhibited decreased depressive symptomology and decreased behavioral problems (aggression, fighting, disruptive actions) as a result of yoga intervention.  Yoga curriculum for children with emotional and behavioral disorders appears to assist in the development of social and emotional well being and health.

Yoga for Employee Health and/or Stress Reduction

Wolever RQ, Bobinet, KJ, McCabe K, Mackenzie ER, Fekete E, Kusnick CA, Baime M. Effective and viable mind-body stress reduction in the workplace: A randomized controlled trial. Journal of Occupational Health Psychology.; 2012:17:246-258

Highly stressed employees are subject to greater health risks, increased cost, and productivity losses than those with normal stress levels. To address this issue in an evidence-based manner, worksite stress management programs must be able to engage individuals as well as capture data on stress, health indices, work productivity, and health care costs. In this randomized controlled pilot, our primary objective was to evaluate the viability and proof of concept for two mind-body workplace stress reduction programs (one therapeutic yoga-based and the other mindfulness-based), in order to set the stage for larger cost-effectiveness trials. A second objective was to evaluate 2 delivery venues of the mindfulness-based intervention (online vs. in-person). Intention-to-treat principles and 2 (pre and post) × 3 (group) repeated-measures analysis of covariance procedures examined group differences over time on perceived stress and secondary measures to clarify which variables to include in future studies: sleep quality, mood, pain levels, work productivity, mindfulness, blood pressure, breathing rate, and heart rate variability (a measure of autonomic balance). Two hundred and thirty-nine employee volunteers were randomized into a therapeutic yoga worksite stress reduction program, 1 of 2 mindfulness-based programs, or a control group that participated only in assessment. Compared with the control group, the mind-body interventions showed significantly greater improvements on perceived stress, sleep quality, and the heart rhythm coherence ratio of heart rate variability. The two delivery venues for the mindfulness program produced basically equivalent results. Both the mindfulness-based and therapeutic yoga programs may provide viable and effective interventions to target high stress levels, sleep quality, and autonomic balance in employees.

Stussman BJ, Black LI, Barnes PM, Clarke TC, Nahin RL. Wellness-related use of common complementary health approaches among adults: United States, 2012. National health statistics reports; no 85. Hyattsville, MD: National Center for Health Statistics. 2015. 

Complementary health approaches include an array of health care systems, therapies, and products with a history of use or origins outside of mainstream medicine. Examples include yoga, chiropractic or osteopathic manipulation, and acupuncture. Previous studies have shown that many individuals use complementary health approaches for disease prevention and to improve health and wellbeing, or to relieve symptoms associated with chronic diseases or the side effects of conventional medicine(s).

The Effect of Yoga on the Brain

Sara W. Lazar, Catherine E. Kerr, Rachel H. Wasserman, Jeremy R. Gray, Douglas N. Greve, Michael T. Treadway, Metta McGarvey, Brian T. Quinn, Jeffery A. Dusek, Herbert Benson, Scott L. Rauch, Christopher I. Moore, and Bruce Fischl. Meditation experience is associated with increased cortical thickness: United States, 2006. 

Brain regions associated with attention, interoception and sensory processing were thicker in meditation participants than matched controls, including the prefrontal cortex and right anterior insula. Between-group differences in prefrontal cortical thickness were most pronounced in older participants, suggesting that meditation might offset age-related cortical thinning. Finally, the thickness of two regions correlated with meditation experience. These data provide the first structural evidence for experience-dependent cortical plasticity associated with meditation practice.

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