The Latest Yoga Research
People are seeking yoga practice for health benefits, and science is documenting its effectiveness. In the United States, 9.5% of adults—about 21 million people—reported that they practiced yoga as a complementary health approach in 2012 (Clarke et al. 2015). Yoga practitioners noted greater health benefits than adults who tried other complementary health practices. Reasons cited for doing yoga included wanting greater wellness, feeling better emotionally, exercising more, eating better, and cutting back on alcohol and cigarettes. These objectives reveal a relationship between interest in yoga and a desire for healthy lifestyle habits (Stussman et al. 2015).
Ongoing research continues to reveal many associated health benefits. Here’s a snapshot of current research highlights and examples of practical applications.
Yoga Research Highlights
“What’s most exciting to me about research into yoga’s benefits is that there finally isresearch,” says Beth Shaw, founder and president of YogaFit® Training Systems Worldwide in New York City. “For years, no one had or was willing to spend money on studies. Now we know that yoga and meditation truly heal. We ‘knew’ that before, but now, more and more, there’s scientific proof.”
While limited funding remains a challenge, yoga research studies in clinical settings have tripled in the past 10 years (Jeter et al. 2015). Drivers include the need for healthcare professionals to understand yoga’s effects; motivation among yoga community leaders to validate traditional practices; and, for those wanting to manage healthcare costs, an interest in identifying viable preventive self-care, stand-alone therapies, or adjunctive therapies that complement prescription medications.
A consistent definition of yoga is essential in order to discuss research. In a 2014 study, neuroscientist and lead study author Tim Gard, PhD, noted that most yoga research emphasizes the following four categories: ethics, postures, breath regulation and meditation (Gard et al. 2014) (see the sidebar “Yoga From a Traditional and Research Perspective,” for more). For purposes of this article, therefore, we’re not looking at physical fitness benefits, but rather at overall health benefits from integrated practice.
Lack of standardization in yoga research presents a challenge. Studies with less risk of bias include systematic reviews and randomized controlled trials (RCTs). However, yoga styles vary—an analysis of RCTs found 47 different styles (plus 30 yoga breathing techniques) among 312 RCTs (Cramer, Lauche & Dobos 2014). Not all studies identify the style used, and protocols vary in frequency and duration. Many studies include all elements of ethics, postures, breathing exercises and meditation, but that is not true in every case. Moreover, yoga is individualized and integrative, and RCTs focus on uniform treatments and specific endpoints. Therefore, RCT methodology limits the ability to evaluate individualized programs and broader healing outcomes—hallmarks of real-life yoga practice.
Against this backdrop are the following highlighted findings from peer-reviewed studies:
Quality of Life
Yoga practice is associated with health-related quality of life [HRQOL] improvements. In general, practitioners report HRQOL improvements from yoga practice. “The improved sense of well-being [from yoga practice] is exciting because this yields greater program adherence,” says Amanda Frame, DNP, E-RYT 500, master trainer for YogaFit, from Evans, Georgia.
However, particular practice components, such as meditation and postures, are associated with different benefits. In a cross-sectional analysis of 309 healthy adult survey respondents, people who practiced community-based meditation and breathing exercises showed higher scores in mental-health life quality. On the other hand, practitioners with more years of postural practice, particularly in class settings, scored highest on physical aspects of HRQOL (Birdee, Ayala & Wallston 2017). More studies are needed to identify protocols and effects for specific populations, yoga styles and practice settings.
Lower-Back Pain and Arthritis
Yoga may be as effective as physical therapy for chronic lower-back pain [LBP]. The largest yoga and back-pain study to date showed that yoga is as effective for helping people manage mild to moderate chronic back pain as physical therapy is (Saper et al. 2017). Boston Medical Center and Harvard University researchers and colleagues in seven affiliated health centers evaluated 320 subjects for 1 year in a randomized clinical trial. Subjects participated in either a yoga program, physical therapy or health education. Yoga practice included relaxation and meditation, breathing, yoga philosophy, poses and final relaxation. The yoga program was customized for LBP, so the results cannot be generalized to all yoga classes.
Yoga may help people with rheumatoid arthritis (RA) or osteoarthritis (OA). A meta-analysis of 12 clinical trials with a total of 589 participants found that yoga practice helped people with OA reduce pain, stiffness and swelling. However, physical function and psychosocial well-being benefits could not be substantiated, given the diversity of outcome measures. Iyengar and hatha were the most frequently used yoga styles (Cheung, Park & Wyman 2016). The largest study of OA and RA found that yoga practice improved physical pain, general health, vitality, activities of daily living, balance, upper-body strength and mental health. Subjects still enjoyed the benefits 9 months after the program ended (Stephens 2017).
Heart Disease and Diabetes
Yoga may reduce heart disease risks. “I’m very excited about the impact of pranayama on cardiovascular disease and hypertension,” says Ina Stephens, MD, associate professor of pediatrics and co-director of the Medical Yoga Initiative at the University of Virginia Medical Center in Charlottesville, Virginia. Stephens, who is also an RYT 500 and an NASM-certified personal trainer, adds that this is an area with important potential. The American Heart Association says yoga practice, not to meet physical exercise requirements, but rather to increase physical, mental and emotional well-being, can be used to improve heart health as a preventive measure or after a cardiac event (AHA 2013).
Stephens notes that—likely because of yoga’s effect on the autonomic nervous system, emotion regulation and chronic stress—numerous studies have found that practice (among diverse patients) led to improvements in blood pressure, lung capacity, respiratory function, heart rate, circulation and heart rate variability, among other biomarkers. The studies featured different yoga styles and included meditation, breathing, postures and, in some instances, lifestyle modifications, such as adopting a primarily plant-based diet or joining a supportive practice community (Stephens 2017).