Slate contributor Brian Palmer recently dubbed yoga “the new prayer: the risk-free, cost-free solution to all of your medical problems.” Scientific evidence to date, contends Palmer, is vastly outpaced by the cultural myth of yoga’s effectiveness, and yoga’s benefits are unlikely to outperform those of exercise. Yet while yoga and prayer have shared origins in spiritual or religious traditions, there are wide-ranging implications should such origins preclude empirical investigation.
For one, the impact of spirituality, religion, and mindfulness on health and wellbeing would remain unstudied; a great loss, as such research frequently indicates beneficial effects. In addition, while many yoga practitioners conceptualize yoga as a spiritual practice, many also perceive it as primarily secular and fitness-based. Such differences in belief may circumscribe or moderate research outcomes. It is unlikely that those who pray share a similar dichotomization.
Palmer raises a number of valid concerns, although none warrant his conclusion that “yoga doesn’t … fit into a clinical trial.” Among them: The heterogeneity of yoga practices are difficult to operationalize and assess. Which components are most effective, and for which medical concerns? In yoga’s defense, this issue applies to most modalities of Complementary and Alternative Medicine (CAM).
Dr. Crystal Park (full disclosure: my mentor) and colleagues are taking the first step towards tackling this concern. Their NCCAM-funded project is developing an instrument that assesses the extent to which various yoga practices, philosophical elements, and other components are featured in yoga interventions. Researchers will then be able to assess whether certain aspects of yoga interventions are more predictive of successful outcomes than other aspects.
Palmer also expresses qualms regarding individual differences in yoga practice. What about those who breathe deeper, hold poses longer, or meditate “better”? Yet similar issues confound exercise intervention research lacking objective measurements, which may assign exercise homework at a particular intensity, only to be confounded by individual differences in metabolism, exertion, errors in self-reporting, or so on.
Likewise, those prescribed homework in a psychotherapy intervention may differ on the extent to which they privately and successfully implement the strategies or techniques. Such issues arise across many forms of intervention research and can be rectified with the use of objective instrumentation, such as ecological momentary assessment and accelerometers.
Most problematic, for Palmer, are the methodological weaknesses characterizing yoga research to date. Most published reviews of yoga’s benefits conclude that the poor quality of trials precludes definitive conclusions regarding yoga’s efficacy, and a surprisingly large number of trials demonstrate null findings (i.e., no effect). When studies do not fit with yoga’s image as cure-all, the mainstream media fails to report them, engendering a highly skewed popular perception of yoga’s benefits. Yet the media has long cherry-picked sexier research findings while ignoring their homelier, non-significant counterparts. Take, for instance, the notoriously changeable media reputation of nutrition, weight loss, and dietary supplement research, due to selective reporting.
While yoga may be no more effective than exercise, as Palmer argues, yoga curricula have been linked to improvements in characteristics related to health and well-being in other studies, including mindfulness, self-compassion, spirituality, and the relaxation response. Such gains are unlikely to result from participation in exercise alone. When these components are combined with (and/or result from) yogic practices, a “whole system” emerges that may synergistically outperform the sum of its parts. Neglecting to assess these components and their additive effects because of yoga’s origins in spirituality would represent a great oversight (and disservice) to science and public health, both of which stand to gain from a better understanding of behaviors that may interweave multiple health benefits in one package.
Nevertheless, Palmer is absolutely correct that yoga’s PR image has vastly outgrown the emerging scientific evidence base. I can understand why, to the staunch empiricist or those wary of CAM, yoga research may at best be viewed as squandering time and resources, at worst threatening the foundations of empiricism itself. After all, yoga’s pop culture friendliness with astrology, new ageism, and magical thinking do little to assist perceptions of its worthiness for scientific study. Yet Palmer’s critiques of yoga research apply equally to CAM and other forms of intervention research, and are addressable with time, funding, and increased methodological rigor.
Perhaps the best inadvertent rebuttal to Palmer’s piece is a recent article published in prestigious medical journal The Lancet, Should Your Patient Be Doing Yoga? Says Shri Mishra of the University of Southern California, “We have not reached a point where we can say there is good scientific evidence that yoga is beneficial. Despite [this], many patients do seem to benefit. There is therefore every reason to continue researching into this area to determine which patients, with which medical conditions, attending which type of yoga class, might profit from its practice.”
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