Yoga, an ancient tradition that originated approximately 5,000 years ago in Central Asia, is a complete system of mental and physical practices for health and well-being. Predominantly practiced within the philosophical context of Ayurvedic medicine in India, yoga as a mind-body therapy is now also increasingly popular in the West, practiced by approximately 15 million individuals. With 13.8 million cancer survivors estimated in the US in 2010, many cancer patients and survivors undoubtedly are practitioners of yoga. As noted in national survey data on cancaer survivors in the United States, yoga practice has continued to increase, especially among females, with more than 800,000 survivors (5%) reporting its use in 2007.[1,2] As a practice that aims to unite body, mind, and spirit, yoga is a system of learning that includes eight "limbs" or aspects, the most common being the asanas (postures), pranayama (controlled breathing techniques), and dhyana (meditation).
Yoga is much more than the practice of exercises and breathing, however, as it is viewed as a "tradition of lifestyle, health, and spirituality," with practices integrated into daily life to create balance, health, and harmony. The other limbs on the metaphorical yoga tree include focus on individual and universal ethics (niyama and yama), control of the senses (pratyahara), concentration (dharana), and bliss (samadhi). As stated by Patanjali, the renowned yoga teacher and author of the Yoga Sutras (a philosophy of yoga composed between 200 BC and 300 AD), "Yoga is the cessation of compulsive functions of the mind so the seeker can stand in the true essence of their nature."
Asanas (pronounced AAH_sanas) include simple to complex body postures, and are noted to exceed 800,000 variations in the ancient yogic literature, although only about 84 are used in current-day practices. Postures are coordinated with the flow of breathing to promote stretching and balancing, and are held for 5–20 breaths. Variations in yoga breathing exercises include, but are not limited to:
• slow, deep abdominal breaths with extended exhalation;
• sustained breath holds;
• alternate nostril breathing; and
• rapid abdominal breathing.
These breathing exercises are thought to influence the sympathetic nervous system and metabolic activity. Meditation practices vary, often using mantras (repeated recital of phrases) and practices to quiet the thoughts in the mind. As yoga moved to the West, it gained recognition by the National Center of Complementary and Alternative Medicine (NCCAM) as a mind-body therapy that can be practiced in a guided group setting and/or as an individual self-care activity for wellness, symptom management, and overall health promotion.[4–6] Yoga practices also vary widely depending upon the lineage that is being taught; they may range on a continuum from very quiet and still practices of meditation only (Yoga-Nidra) to more intense forms that may include continuous and powerful movements (Ashtanga or power yoga) and practice in a heated room (Bikram or hot yoga).
Also noted over the past two decades is the emergence of yoga therapy as a distinct therapeutic discipline, defined as "the process of empowering individuals to progress toward improved health and well-being through the application of the philosophy and practice of yoga." The International Association of Yoga Therapists (IAYT) continues to strive for a clear and functional definition of yoga therapy, high educational and practice standards, increased public recognition, and strong research documenting effectiveness. In addition, a call to address health insurance reimbursement for yoga has been made, with recent significant and cutting-edge changes noted in federal-level Medicare coverage for yoga practice among people with heart disease.[8,9]
HOW IS YOGA CURRENTLY USED IN CANCER CARE?
Based on National Health Interview Survey data, the number of individuals in the US who practice yoga has increased from 4% to 5% over a 5-year period, which means more than 800,000 cancer survivors are now going to the mat across the US.[2,10] Ranked as the sixth most common CAM therapy in the US cancer survivor population of 13.8 million, yoga is the third most common practice, followed by deep breathing exercises (14%) and meditation (9.7%). This trend of increasing CAM use is anticipated to continue, affecting the nature of healthcare for years to come. As a result, oncology nurses and other healthcare providers will continue to encounter an increasing number of CAM users in their patient population, many of whom will seek yoga as a way to address health concerns.
Bothersome and frequently occurring symptoms such as insomnia and depression significantly predict the use of yoga among cancer survivors, with odds of use influenced by gender. Female cancer survivors are much more likely to do yoga, with symptoms such as depression increasing use among males. Preliminary research on yoga for chemotherapy-induced nausea and vomiting has indicated potential benefits. Yoga is also commonly used for chronic conditions such as low back pain,[12–14] arthritis, migraine headaches, irritable bowel syndrome, insomnia, stress, anxiety, and depression.[18–20] Thus, given the increasing use of yoga as patients seek to manage symptoms and promote well-being, it is important to understand the types of yoga that patients are seeking, the preparation and credentials of yoga teachers, and potential benefits and risks.
Many different styles of yoga are offered throughout the community and at integrative medicine (IM) centers, with variation related to teacher preparation, credentialing, and availability. Numerous yoga training programs exist within the US and abroad, and include Viniyoga, Yoga Nidra, Ashtanga, Kundalini, Iyengar, and others. Yoga Alliance® currently offers credentialing designated as RYT-250 and RYT-500, indicating that the practitioner is a Registered Yoga Teacher who has completed the number of hours specified. Much variation exists in yoga class availability across diverse communities, however, and study is needed to determine access for individuals with chronic illness.
Research is being conducted by the National Cancer Institute’s Office of Cancer Complementary and Alternative Medicine (OCCAM), to determine the scope of services at IM centers across the United States (personal communication, Isis Mikhael, MD, MPH, DrPH, Research Development and Support Program Director at OCCAM, National Cancer Institute, May 2010). Of importance, however, is the appropriate fit of the class to individual needs, as well as the experience of the teacher in yoga practice to address health concerns. This will help to ensure that a particular yoga regimen has therapeutic value, while maximizing safety and positive outcomes for all individuals.
Yoga is frequently offered along with a diverse array of CAM therapies such as massage, guided imagery, hypnosis, naturopathy, and acupuncture at IM and cancer centers across the country. More information about these centers is available at the Consortium of Academic Health Centers for Integrative Medicine (CAHCIM) website. In addition, other community-based cancer support organizations often provide free yoga classes (eg, Gilda’s Club Support Community).
Private community-based yoga studios also offer yoga classes for specific health conditions (such as cancer, back pain, weight loss, eating disorders, etc) and specialized health-related education and training. This enhances the recognition of, and attention to, the unique needs of cancer patients and survivors. Further study is still needed, however, to determine the extent to which CAM practices such as yoga are made available to those affected by cancer, as well as educational yoga training programs addressing their needs.
WHAT IS THE EVIDENCE ON YOGA AND CANCER?
Although yoga has been practiced for thousands of years to enhance physical and psychological well being, research into yoga has only been conducted for the past several decades. Studies examining use of specific CAM practices are now more frequently noted in the literature, with varied findings depending on the practice studied. The emerging literature on yoga during the cancer experience, most often conducted with breast cancer patients, provides support for feasibility and effectiveness of yoga practice for improvements in insomnia, mood, and overall quality of life, although more clinical trials are needed.[21,22] Benefits of yoga interventions include enhanced respiration; improved appetite and bowel habits; increased sense of peace and tranquility; fewer cancer- and treatment-related symptoms; and improved sleep quality, mood, and cancer-related distress.[23–30] An initial pilot study with non–small-cell lung cancer patients (stage I–IIIa) indicates that yoga improves overall mood and emotional functioning, and that practice was possible without increasing dyspnea in this population with respiratory compromise. In a small study (N = 20), Ulger and Yagli noted that yoga helped to promote relaxation and reduced stress among patients undergoing treatment for breast cancer, hence improving quality of life. Similar findings were noted among breast cancer patients undergoing radiotherapy, with a significant improvement in positive affect, emotional and cognitive function, anxiety, and depression.[32–34] In breast cancer patients, reduction in hot flashes and menopausal symptoms, as well as reduced fatigue, has also been reported. Preliminary research has also documented yoga as a feasible and beneficial option for children with cancer, although further study is needed. Research evidence is also noted for the primary and secondary prevention of ischemic heart disease with yoga practice, and effectiveness during postinfarction rehabilitation. This is of clinical relevance to the cancer population, which is predominantly older and affected by concurrent comorbidities including heart disease and hypertension, and who may be under treatment with potentially cardiotoxic chemotherapy (eg, doxorubicin).
Data also reveal that female cancer survivors (6.4%) are significantly more likely to do yoga than their male counterparts (1.2%). Female cancer patients were found to be 13.5 times more likely to practice yoga than male patients. Doing yoga was also significantly related to symptoms among both genders, with noted increases among males who experienced depression. In addition, the number of symptoms and concurrent comorbidities reported by cancer survivors is significantly greater than that among individuals without cancer (P < .001). As previously noted, and as extensively documented in the literature, symptom burden remains a significant predictor of CAM use among cancer survivors, including practices such as yoga. This is important to consider given the emerging research evidence supporting yoga for low back pain, heart disease, diabetes, and other chronic conditions.[3,12,38]
How yoga affects the human body, mind, and spirit is a complex question. It is widely accepted that yoga practices influence the central nervous system, resulting in a downregulation of the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic nervous system (SNS), thereby decreasing the stress response. Research has documented that yoga decreases salivary cortisol, blood glucose, plasma renin, epinephrine and norepinephrine, and inflammation markers, such as C-reactive protein and proinflammatory cytokines.[39–41] In addtion, yoga practice decreases heart rate and blood pressure, inceases heart rate variability, and increases levels of serum IgA, natural killer cells, and GABA.[39,42–44] Ross and Thomas also conclude that "yoga may be as effective as or better than exercise at improving a variety of health outcome measures."
Research often yields mixed findings, however, indicating the need for further study to determine the effectiveness of yoga interventions for cancer survivors. Of particular importance is the variation that exists across studies in the operational definition of a yoga intervention, use of appropriate control groups, and sample sizes. Not only are numerous styles (lineages/traditions) of yoga practiced across the US and around the world, but different components of yoga practice (classes, home practice, etc) are also included in research designs. In addition, it is important to identify what may be termed a dosing effect, that is, how much yoga practice is needed (how often and how long) to produce desired outcomes and specific health benefits. For example, variation in the extent of yoga practice is noted throughout the research literature, with yoga interventions ranging from 4–14 weeks and including classes that vary from 30–90 minutes. Studies by complementary medicine researchers are underway to address the dosing factor. Further investigation also is needed to determine effects of yoga among diverse populations. Little is known about yoga in the pediatric population, for example, although emerging data are promising.[13,37,45]
In sum, data on yoga benefits vary, supporting the urgent need for further study with strong methodological designs, larger sample sizes, and adequate controls. Currently there is strong evidence of positive outcomes of yoga for asthma and hypertension; good evidence to support yoga benefits for those with other chronic conditions such as arthritis, depression, cardiovascular disease, and mental illness; and emerging data to suggest that yoga should be considered for fatigue, diabetes, pain, and insomnia (Natural Standard Database).
WHAT ARE THE POTENTIAL RISKS?
As with any physical practice that involves movement and positioning, yoga postures carry the risk of injury if performed inappropriately or too vigorously by individuals who are unprepared or limited in any way. In particular, one needs to be conditioned for the more rigorous, aerobic, and intense forms of yoga that have been developed recently in the West, such as Bikram, Vinyasa, and Ashtanga yoga. In addition, yoga practice must be tailored to the needs, abilities, and limitations of individuals compromised by specific illnesses, changes caused by the aging process, and developmental concerns. As yoga has become more popular among the elderly, specific concerns such as hypertension, osteoporosis, arthritis, respiratory compromise, and cardiac disease need to be addressed, and yoga classes must be tailored to avoid exacerbation of symptoms, risk of falls, and injury.
Potential risks of yoga practice also include overstretching, lower back strain, and knee, wrist, or shoulder injuries from improper positioning and extended length of the pose. Specific case studies of lateral collateral ligament injury and epiphyseal tibia separation associated with yoga have been discussed in the literature, although reports are sparse.[47,48] Neck injuries can occur with inverted postures such as the shoulderstand and headstand, which are also contraindicated for individuals with hypertension and glaucoma. Progressive optic neuropathy, vision loss, and changes in intraocular pressure have occurred with practice of the headstand (Sirsasana) posture, an advanced posture that is only done in high-level classes by experienced practitioners.[49–52]
Gary Kraftsow, Director of the American Viniyoga Institute (AVI), recommends that proper preparation should precede any asana that may be risky for the joints, and that these should occur at the end of a yoga class, followed by simple counterposes to neutralize the body. Prevention of injury is essential and rests upon the awareness and skill of the yoga teacher, and recognition of limitations by participants. In particular, in recommending yoga programs for cancer patients who are actively undergoing treatment, it is important to take into consideration the potential for treatment side effects such as nausea and vomiting, dizziness, and fatigue. An astute, credentialed teacher will closely observe and monitor participants, providing chairs and props when needed, therefore nurses should inform patients how to select classes and practitioners.
WHAT’S THE BOTTOM-LINE MESSAGE?
To various degrees, data support the positive effects of yoga for asthma, hypertension, anxiety, depression, cardiovascular disease, and overall quality of life, all of which are concerns of patients with cancer and cancer survivors. Although much is known, further research is needed to fully understand the physiological and psychological effects of yoga on the human body, mind, and spirit, and how this ultimately influences the health and well-being of individuals with cancer. It is important to note that the global yoga community is actively involved in methodologically sound research to determine efficacy and effectiveness of yoga for management of a wide range of symptoms and conditions, and to improve one’s overall well-being. The ancient wisdom of yogic tradition, long-standing history of its use across the world, anecdotal reports of enhanced well-being, and the strength of the emerging data yield support for yoga practice. It is, in essence, a practice that can be used safely with guidance and respect for its tradition, resulting in positive outcomes.
As nurses, we should recognize the potential value for patients and caregivers, including ourselves, and incorporate yogic principles into our holistic integrated plan of care. We should aim to educate and guide those patients who seek to incorporate yoga into their self-management plan of care, during the cancer treatment process and throughout the survivorship period. It is our responsibility to be informed, to understand the evidence base for yoga, and to appreciate its strengths and limitations in order to guide patients toward safe and appropriate practice. We have the vital resources at our fingertips. We can direct patients to IM centers, learn about processes for yoga certification, guide our patients to skilled yoga teachers, and enable appropriately selected patients to benefit from the yoga tradition.