Ask the Yoga Doc: Problems Besetting Yoga Research

One of my students asked me the other day why the medical establishment seems so slow to recommend yoga, when it is so obvious that yoga is good for a whole host of medical conditions, like chronic back pain, stress, and premenstrual tension, to name but three. The simple answer is that research in yoga is rarely acceptable to Western-trained physicians. I wrote a paper which was published last year in the International Journal of Yoga Therapy on the topic of difficulties in Ayurvedic research, which I entitled: “Square Pegs and Round Holes: Should Evidence-based Medicine Apply to Ayurveda”. Many of the same problems pertain to yoga and yoga therapy research.

The thrust in medicine these days, and for some time now, is to have information based, as much as possible, upon hard evidence, rather than anecdotal data or experiential considerations. Research articles submitted to peer-reviewed journals are routinely rejected, unless they are randomized, controlled, and, preferably, also double-blinded. Of these three requirements, only the first can be achieved in yoga and yoga therapy research. Let’s look at why this is so.

Certainly, a yoga study can be set up wherein candidates fill out questionnaires and can be selected by chance for yoga or not, i.e. randomized. The problem is the “not” part. There is no way to set up viable controls. You either have yoga, or you do not. You cannot have “sham yoga”, although you can compare yoga to other forms of exercise, or to no exercise at all, for that matter. Obviously, you cannot blind or even double-blind such studies. What I mean is that the teacher, and likewise the student, clearly knows whether or not he or she is either teaching or taking a yoga class. 

And this is where investigator and participant bias comes in. Since everyone knows, or assumes, that yoga is good for her, anyone randomized to receive something else will feel disappointed. Yoga teachers assigned to offer something else will be half-hearted about it. A dispirited participant will not yield accurate data.

By contrast, take a study investigating the efficacy of a medication. Here one can easily control enrollees to receive either the study capsule, or a placebo which looks just the same, and it can be done in such a way that neither the person administering the pill, nor the one taking it will know whether it is the study drug or the placebo until the end of the study, when a computer print-out reveals all.

There are other problems in studying yoga as well. Standardization of sequences, length of time poses are held, whether or not scrupulous attention is given to proper foundation and alignment, duration of practices, reliability of accurate home practice, smallish numbers of participants (often with high drop-out rates, especially in the “no-yoga” control groups), multiplicity of teachers, and short length of study time come to mind. Big studies are costly of time and money, and grants to fund such studies are hard to come by; pharmaceutical companies tend to fund the big medical studies, and they are not interested in yoga research, since they have nothing to gain from them.

My advice is to convince your doctor to give yoga a try, and let her see for herself the multitude of benefits. Certainly, the personal experience derived will be anecdotal, and it therefore will fly in the face of evidence-based data. Yet yoga has been around a lot longer than “sound scientific” studies. Medical information has a turnover rate of less than ten years. Take for instance, dietary recommendations for diverticular disease. Not all that long ago, patients with that condition were advised a strict low-residue diet; now it is just the opposite. Consider the theories about best position for newborns to avoid Sudden Infant Death Syndrome; we have turned our babies over and over, almost like rotisseries, and we still don’t know the answer. Yoga, on the other hand, has evolved slowly over centuries, although a recent slew of yoga entrepreneurs have rushed to the marketplace with their “new and improved methodologies, thereby somewhat confusing the issue by suggesting that yoga is good, but some yoga (i.e. theirs) is better than other yoga.

Yoga is more closely akin to art than science; with medicine, increasingly, it is the opposite. This we as teachers know full well. We merely have to keep our students coming back for them to find out the truth: yoga is very good for them. And “them” is just about everybody, as far as I am concerned!