A
search of yoga science returns over a
hundred million results on Google. Yet, a 2014 scoping review of yoga
intervention components and study quality by Elwy and colleagues concluded that
yoga is less than scientific and highlighted the inadequate reporting and
methodologic limitations of current yoga intervention research. What is getting
in the way of yoga becoming an evidence-based practice?
To
start with, yoga resists definition. Yoga can be postures, meditation,
breathing techniques, paying attention, or all of the aforementioned, to name a
few possibilities. Yoga is difficult to pinpoint because it is an ever-evolving
practice that changes based on the times in which and by whom it is practiced
and taught. Further, the most effective yoga interventions are individualized,
which “makes it incompatible with gold standard double-blind research studies
from the get-go,” says Carol Horton, Ph.D., author and co-editor of two books
on contemporary North American yoga.
Formal
yoga research needs to start "paying careful attention to the duration,
frequency, dose, location of yoga, additional emphases of yoga, instructor
training, home practice description, and the potential sources of bias that can
result in low-quality yoga intervention studies," conclude Elwy and
colleagues. Yet, moving yoga towards an evidence-based practice is not and
should not be the same as medicalizing yoga, which largely misses the point of
yoga, says Doug Keller, distinguished professor in the Master of Science in
Yoga Therapy program at the Maryland University of Integrative Health. He adds
that researchers will have to be clear and specific about what aspects and
practices they choose to study, and remain cognizant that this is a selective
choice, and cannot necessarily be generalized into conclusions about yoga
itself.
That's
why Laura Schmalzl, Ph.D., from the Division of Behavioral Medicine at the
University of San Diego School of Medicine, prefers the term "yoga-based
practices" (YBP) in her research rather than the all-encompassing “yoga.”
"We need to be pragmatic and operationalize the different aspects of YBP in
order to study, measure, and understand the physiological, neurological, and
psychological mechanisms that underlie their effects. The aim of formal yoga
research should not be to prove that YBP work but to investigate how they work, so that they can be more
efficiently applied to different populations," says Schmalzl.
The
yoga industry has seen a proliferation of styles, studios, and yoga lifestyle
products and services that are relentlessly marketed to consumers in “a
confusing mess of proprietary claims reflexively attributed and accepted as
yogic wisdom and privileged insight”, says Keller. The sheer variety of yogic
practices, styles, and approaches also complicates researchers’ task in how
best to define a consistent intervention that is comparable across studies.
The Yoga
Journal’s 2012 Yoga in America survey shows that modern practitioners mostly
seem to consume yoga to improve flexibility (78.3%) as well as for general
conditioning (62.2%), stress relief (59.6%), and overall health (58.5%). However,
there is a significant minority that practices yoga to improve mental health
(36.7%) and for spiritual development (31.7%). People seem to be turning to
yoga in a quest for pain relief, self-improvement and self-care, and better
functioning on both physical and metaphysical levels.
This
begs the question: do academic researchers on yoga really know how to study
yoga in ways that are directly relevant to practitioners? “We don't even
understand the science of stretching thoroughly yet, let alone the precise nature
of the brain-body connection,” notes Horton. By understanding what yoga is good
for, the field can work to create the conditions in which more can share in its
benefits. Schmalzl agrees that yoga research is in its infancy, and that
current scientific studies do not yet have enough direct applications in
practical terms for yoga practitioners. Equally, she says, researchers,
teachers, and practitioners need to learn to talk to each other so that studies
are more relevant to practitioners’ concerns, and to ensure that scientific
findings make it into yoga teacher training curricula.
Yoga
and allopathic medicine should neither be in competition, nor try to co-opt
each other. The answer lies in the middle where yoga and medicine complement and
communicate with each other. To quote Carl Sagan, “Absence of evidence is not
evidence of absence.” Yoga is experientially valuable to people who practice
it. But to become truly modern and to remain a relevant modality, yoga needs to
take evidence seriously.
Sources:
Elwy,
A. R., Groessl, E. J., Eisen, S. V., Riley, K. E., Maiya, M., Lee, J. P.,
Sarkin, A., & Park, C. L. (2014). A Systematic Scoping Review of Yoga
Intervention Components and Study Quality. American
Journal of Preventive Magazine, 47(2),
220–232. Cited from http://www.ajpmonline.org/article/S0749-3797%2814%2900151-2/fulltext
Yoga
Journal (2012). Yoga in America. Yoga
Journal Magazine. Cited from personal copy.
