More than 15 million people are believed to be practicing yoga in America today, and a great many of them are doing so with the encouragement of a doctor or therapist to improve their overall health.
As interest in yoga continues to expand, scientists are beginning to refine their methods for accurately gauging the health benefits of the millennia-old practice.
Crystal Park, a professor of psychology in the College of Liberal Arts and Sciences who is affiliated with UConn’s Center for Health, Intervention and Prevention (CHIP), is leading a national team of researchers in developing a standardized assessment tool that can be used to measure and compare different yoga therapies.
The research is being supported by a $1.5 million grant from the National Institutes of Health National Center for Complementary and Alternative Medicine or NCCAM.
“A lot is happening in the yoga world right now,” says Park, a yogi who has been regularly practicing yoga for six years. “But one thing the National Center for Complementary and Alternative Medicine is concerned about is whether the studies are being done well, and there is no good way right now for researchers to compare the interventions they are doing.”
Park is the principal investigator for the five-year study. Collaborators include A. Rani Elwy and Susan Eisen from Boston University’s School of Public Health; Dr. Chris Streeter from Boston University’s School of Medicine; and Erik Groessl, director of the University of California, San Diego’s Health Services Research Center. UConn psychology graduate student Kristen Riley and several UConn undergraduates will assist Park in gathering the research data.
The research will include literature reviews, surveys, focus groups, direct observations, and personal interviews with yoga teachers and practitioners in an attempt to break down, measure, and ultimately better understand how different forms of yoga therapy may improve physical, mental, and spiritual health.
Research studies have shown that yoga can be beneficial for people with many specific health problems, including cardiovascular disease, cancer, arthritis, eating disorders, and chronic pain. Yoga has been known to reduce stress, increase strength and flexibility, and improve concentration and mood.
The problem, Park says, is that it is difficult for researchers to compare the effectiveness of different yoga interventions because yoga practice is, by its nature, so diverse.
“You may read a study in which individuals did yoga for back pain or did yoga for a headache, but was it the same yoga intervention? Probably not,” says Park. “Because yoga interventions can differ dramatically from each other, it is hard to compare yoga across studies. Our project is designed to identify what the different dimensions of yoga interventions are, and then create an instrument that is reliable and valid for researchers to use to describe their interventions.”
The word yoga means “union” in Sanskrit, the language of ancient India where yoga began. It is meant to convey the union of mind, body, and spirit. Yoga is most commonly affiliated with the Sanskrit word “asana,” which refers to the practice of physical postures or poses. Asana is one of eight “limbs” of yoga. Other major limbs of yoga include meditation (dyhana); breathing exercise (pranayama); concentration (dharana); and enlightenment (samadhi).
There are also many different styles of yoga, such as the fast-paced and intense Ashtanga or power yoga; Iyengar yoga, which concentrates on holding poses and proper body alignment; and Bikram or hot yoga, which is practiced in a 95 to 100-degree room and is meant to loosen muscles and cause sweating as a form of cleansing.
So when a study shows that a yoga intervention helped reduce a cancer survivor’s stress, for instance, it is important for researchers to know what caused the reduction. Was it doing yoga poses while concentrating on breathing? Was it the meditation? Was it a more aggressive form of yoga practiced in a warm room? Did individuals feel more relaxed in a group with other cancer survivors or was the intervention most helpful when they took time to reflect on their yoga experience privately at home?
Park says a lack of standardized controls in yoga studies has also presented challenges. If the yoga intervention involves movement, for example, a possible control group might be individuals participating in an African dance class or a bicycling class. But those controls would not control for other aspects of yoga, such as meditation or breath work.
“I think it’s pretty clear that yoga studies show benefits,” Park says. “The problem is there are inadequate controls. Anyone doing an intervention can do better than someone not doing an intervention. It’s just that we’re not sure what aspects of that particular intervention really are helpful. If you do a study and are just looking at people, people in the attention group tend to do better. So it’s really hard to know how much power something like yoga has, and what about the yoga is leading that change. I think this tool, in the end, will be very helpful in answering that question.”
An expert in the psychology of stress and coping, Park has been a member of UConn’s psychology department for the past 12 years. She has published more than 100 peer-reviewed papers and currently serves as associate editor of Psychology & Health. She also is co-editor of the International Journal for the Psychology of Religion and associate editor of Psychology of Religion and Spirituality.