09/10/2012 04:59 pm ET Updated Nov 10, 2012

The 'Science' of Yoga Marches On: Are Yogis Even Listening?

Publication last spring of William Broad's The Science of Yoga: The Risks and Rewards provoked a storm of controversy among American yogis. Partly it was the air of sensationalism that surrounded some of Broad's highly-charged claims: first, that yoga could cause serious, even life-threatening injuries, and second, that the entire yogic enterprise had begun as a Hindu "sex cult."

But the real source of dismay, perhaps, was that yoga, which has flourished in the Obama years as something of a pop-culture "wild child," was finally being observed and evaluated by the outside world. And not just by adults, but by research scientists to boot. Could this newfangled grassroots movement -- which can morph into a girl-power rave party at the drop of a yoga mat -- actually survive "serious" scrutiny?

Broad suggested that it might, but only if yoga were to shed its deep-seated narcissism and penchant for celebrity glitz and begin repositioning itself as part of the mainstream "wellness" movement. How? By establishing more professional teacher training programs with stricter licensing standards, for one. That would help reduce the incidence of injury and might allow fledgling yogis to treat a wider range of health problems more credibly. And second, by subjecting yoga's far-flung health benefit claims -- some of them dubious on their face -- to more rigorous scientific testing and validation.

Needless to say, for a movement that seems to harbor -- no, pride itself on -- a zealous disrespect for "Western" medicine and that also defiantly resists government intrusion into its internal affairs -- however unseemly those affairs may be -- Broad's sobering and decidedly adult-sounding message didn't exactly catch fire.

Which is why -- sadly, perhaps -- the latest scientific research work of the National Institute of Health's National Center for Complementary and Alternative Medicine (NCCAM) is likely to produce yet another round of shrugs -- or, depending on the media fall-out, another caustic and contemptuous backlash.

The Center, with its annual budget of $107 million, isn't exactly the scientific or medical mainstream. But it does appear to be following in Broad's footsteps by setting out a formal -- and some would say, rather traditional -- experimental research agenda for yoga. It's subjecting yoga -- and the millions of human bodies practicing its asana postures -- to advanced muscular-skeletal tests (with wires and electrodes, the whole nine yards), but it's doing it with a degree of impartial care and integrity that's unusual -- even incorporating highly-trained yoga instructors directly into the research process.

The test results, so far, are mixed. One NCCAM study supervised by Dr. Karen Sherman of the Group Health Clinic in Seattle found that yoga could provide some relief from lower back pain, a widespread ailment that has resisted conventional therapies. But NCCAM also found that yoga's impact was modest, and that other treatments including spinal manipulation, a hands-on massage technique, were equally effective. (In fact, NCCAM's collection of "recommended practices" for lower back pain doesn't actually list yoga.)

Other NCCAM-funded research by Dr. George Salem at the University of Southern California found an even more surprising result: Many yoga postures aren't working on the joints and muscle groups that yoga teachers typically claim; and worse, in some cases they are adding, not relieving, stress, at least to the physical body.

Take the vaunted "Warrior Pose" sequence. It's one of the most popular and widely practiced asana series -- often touted as a means of instilling balance control. But Salem's tests found that another asana, "Tree Pose," was actually far more useful for this purpose. In his training program at USC, Salem recommends downplaying the Warrior sequence and eliminating or modifying the Sun Salutation and Downward-Facing Dog, two other poses at the heart of contemporary yoga practice.

NCCAM's researchers have also begun to inventory other ailments that yoga marketers and teachers consistently claim the practice will provide relief for -- and have found several popular claims wanting. Asthma? The Internet is filled with short instructional videos claiming that yoga's deep-breathing techniques will widen bronchial tubes and make asthma attacks less likely. But according to NCCAM, there is no sound evidence to support that claim.

And arthritis? Even Broad, citing the work of immunologist Kevin J. Tracy and Indian scientist Shirley Telles has endorsed the view that yoga can surely help with degenerative bone diseases like osteoporosis that afflict millions of older people especially. But Salem, who's launched a research program entitled "Yoga Empowers Seniors," disputes that view -- as does a recent review of the scientific literature on yoga and arthritis, which finds that the current evidence of a positive yoga benefit is inconclusive, citing severe methodological weaknesses in study design.

What does yoga actually help with? Despite their skepticism, NCCAM researchers clearly expect to document yoga's positive health benefits over time. But much as Broad did in his book, they are cautioning that far less is actually known -- and even less has been conclusively proven -- about how yoga actually helps when it does, and that anecdotal evidence alone, even from satisfied yoga customers, isn't statistically representative, and can't be treated as scientifically valid.

Even in the best cases, some benefits attributed to yoga may not even be unique to yoga. For example, in a number of recent studies, researchers have compared yoga's impact with that of other non-traditional treatment modalities, including simple stretching exercises. While yoga provided a positive benefit, the other techniques did just as well, casting doubts on yoga's perpetual claim to therapeutic uniqueness as a mind-body healing system.

Past studies have also shown that non-yogic meditation techniques such as TM and qigong can have just as much therapeutic value as yoga does for depression or substance abuse -- with less potential for physical injury.

So far, the work of NCCAM hasn't attracted much media attention. But expect all that to change as more and more studies come online, and the research begins to challenge -- as well as support -- other long-standing yoga health claims. Many critics are likely to take issue with NCCAM's experimental research methods which, thus far at least, seem to replicate the industry's over-emphasis on yoga's physical or postural aspects, downplaying its potential psychological and spiritual benefits.

Still, with the yoga industry continuing to suffer fall-out from the John Friend Anusara sex scandal and from bizarre developments like the Lululemon murders, there are worse things than a government "stamp of approval." Over time, a stronger scientific imprimatur could bring the popular practice more mainstream credibility, allowing it to tap a portion of the almost $2 trillion U.S. wellness market -- tantamount to striking gold.

And in the short term, yoga will surely gain a measure of protection -- and added visibility -- by being brought under the roof of a much wider range of "alternative" treatment modalities, including acupuncture, massage, and Pilates.

But can American yogis voluntarily step down from their Olympian heights and agree, in effect, to be just one of the gang? They may not have much choice if they expect to survive -- and in the end, exploit -- the onward march of science.

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