The Science of Yoga: The Risks and the Rewards (5 page)

I began examining the yogic literature with a sense of wariness. Long ago, while working at the University of Wisconsin on a study of respiratory physiology, I came across a flat contradiction to one of modern yoga’s central tenets—that fast breathing floods the body and brain with revitalizing oxygen. In contrast, a textbook I was reading at the time said the pace of human respiration “can drop to one-half or rise to over one hundred times normal without appreciably influencing the amount of blood oxygenated.” I see now that, in 1975, I underlined that passage quite heavily.

Unfortunately, my survey lived up to my low expectations. Some books and authors shone brightly. (See Further Reading for a list.) But on the whole, I found the literature dull with dreaminess, assertions with no references, and a surprising number of obvious untruths. I wanted tips for tracking down good science but instead got a muddle. The writing, old and new, turned out to run toward the curiously dogmatic and, at best, to contain only a smattering of science. Much of it was similar to what Richard Feynman, a founder of modern physics, disparaged as cargo-cult science—that is, material that appears scientific but lacks factual integrity.

By contrast, my plunge into the scientific literature left me heartened. Federal officials at the National Institutes of Health in Bethesda, Maryland, run a wonderful electronic library of global medical reports known as PubMed, short for Public Medicine. It showed that scientists had written nearly one thousand papers related to yoga—the number rising in the early 1970s and soaring in recent years, with reports added every few days. The studies ranged from the flaky and superficial to the probing and rigorous. The authors included researchers at Princeton and Duke, Harvard and Columbia. Moreover,
the field had gone global. Scientists in Sweden and Hong Kong were publishing serious papers.

But the closer I looked, the more I judged this body of information to be rather limited. Some general topics had been covered fairly well—for instance, how yoga can relax and heal. But many others were ignored, and much of the published science turned out to be superficial. For instance, studies for the approval of a new drug can require the participation of hundreds or even thousands of human subjects, the large numbers increasing the reliability of the findings. In contrast, many yoga investigations had fewer than a dozen participants. Some featured just one individual.

The superficiality turned out to have fairly obvious roots. Research on yoga was often a hobby or a sideline. It had no big corporate sponsors (there being no hope of discoveries that could lead to expensive pills or medical devices) and relatively little financial support from governments. Federal centers tend to specialize in advanced kinds of esoteric research as well as pressing issues of public health, with their investigations typically carried out at institutes and universities. In short, modern science seemed to care little.

The exception turned out to be areas where yoga intersected other disciplines or made bold claims strongly at odds with the conventional wisdom. Such crossroads proved to be scientifically rich. For instance, scientists interested in sports medicine and exercise physiology had lavished attention on yoga’s fitness claims. So, too, physicians had zeroed in on yoga’s reputation for safety.

The limitations of the current literature sent me casting a wide net, and I immediately made a big catch. It was a very old book—
A Treatise on the Yoga Philosophy
—written by a young Indian doctor and published in 1851 in Benares (now known as Varanasi), the ancient city on the Ganges that marks the spiritual heart of Hinduism. It came to my attention because a few Western scholars had referred to it in passing.

I got lucky and found that Google Books had recently scanned Harvard’s copy into its electronic archive, so I was able to download the whole thing in a flash. Its language was archaic. But the author had addressed the science of yoga with great skill, illuminating an important aspect of respiratory physiology that many authorities still get wrong today.

The book surprised me because I had been told that Indian research on yoga—though pioneering—was
typically of poor quality. But I kept finding gems. A curious scientist, often working in India or born in India and doing research abroad, would address some riddle of yoga and make important finds. It happened not only with respiratory physiology but psychology, cardiology, endocrinology, and neurology. The scientists often acted with rigor, going against the day’s tide.

Intrigued, I traveled to India to learn more about these early investigators and eventually came to see them as a kind of intellectual vanguard. Their reports tended to predate the electronic archives of PubMed, making them all but invisible to modern researchers. But their findings turned out to be central to the field’s development.

As I widened my research, I had the great good fortune to sit at the feet of Mel Robin, a veteran yoga teacher and star of yoga science. Mel had worked at Bell Telephone Laboratories (the birthplace of the transistor, the heart of computer chips) for nearly three decades before turning to an investigation of yoga. His labor of love produced two massive books totaling nearly two thousand pages. What Mel did uniquely was roam far beyond the literature of yoga to show how the general discoveries of modern science bear on the discipline. His example encouraged the kind of independent thinking I had begun at the University of Wisconsin.

Over the years, the widening of my research brought me into contact not only with Mel but a wonderful variety of scientists, healers, yogis, medical doctors, mystics, federal officials, and other students of what science tells us about yoga. If science is the spine of this book, they are the flesh and blood.

My focus is practical. In places, the book touches on topics of Eastern spirituality—meditation and mindfulness, liberation and enlightenment—but makes no effort to explore them. Rather, it zeroes in relentlessly on what science tells us about postural yoga. I mean no disrespect to the Hindu religion or spiritual traditions that embrace the big picture. But if this book succeeds, it does so because it limits itself to a poorly known body of reductionist findings. Even so, I should note that I view the scientific process as limited and unable to answer the most important questions in life, as does any true believer. The epilogue explores what may lie beyond.

In the end, my examination revealed not only a wealth of findings but a remarkable lack of
knowledge among yogis, gurus, and practitioners about the reports and investigations. This is pure speculation. But I’d be surprised if the community knows a hundredth or even a thousandth of what scientists have learned over a century and a half.

This book tells that story. In essence, it offers an impartial evaluation of an important social phenomenon that began to stir millennia ago. And if I may, it is the first to do so.

I have structured this book to start with issues of common interest and to end with topics that are less familiar. That flow, it turns out, parallels the development of scientific interest over the decades. So the book has a loose chronological organization.

The portrait of yoga that emerges is quite different in important respects from the usual claims. In some cases, the news is better.

For instance, a number of teachers credit yoga with powers of sexual renewal. The science not only confirms that claim but shows how specific poses can act as aphrodisiacs that produce surges of sex hormones and brain waves indistinguishable from those of lovers. More generally, recent clinical studies give substance to the idea that yoga can improve the sex lives of men and women, documenting how new practitioners report not only enhanced feelings of pleasure and satisfaction but emotional closeness with partners.

The health benefits also turn out to be considerable. While many gurus and how-to books praise yoga as a path to ultimate well-being, their descriptions are typically vague. Science nails the issue.

For example, recent studies indicate that yoga releases natural substances in the brain that act as strong antidepressants, suggesting great promise for the enhancement of personal health. Globally, depression cripples more than one hundred million people. Every year, its hopelessness results in nearly a million suicides.

Amy Weintraub, a major figure in this book, recounts how yoga saved her life by cutting through clouds of despondency.

But if some findings uplift, others contradict the onslaught of bold claims and proffered cures.

Take body weight—a topic of enormous sensitivity for anyone trying to look good. For decades, teachers of yoga have hailed the discipline as a great way to shed pounds. But it turns out that yoga works so well at reducing the body’
s metabolic rate that—all things being equal—people who take up the practice will burn fewer calories, prompting them to gain weight and deposit new layers of fat. And for better or worse, scientists have found that the individuals most skilled at lowering their metabolisms are women. Of course, other aspects of yoga
do
fight pounds successfully. The discipline builds body awareness and its calming influence can help reduce stress eating. Most yoga teachers are lithe, not lumpy. But when yoga succeeds at weight control, the scientific evidence suggests that it does so in spite of—not because of—its basic impact on the human metabolism.

That’s one of yoga’s dirty little secrets. It turns out there are plenty of others, some quite significant.

Yoga has produced waves of injuries. Take strokes, which arise when clogged vessels divert blood from the brain. Doctors have found that certain poses can result in brain damage that turns practitioners into cripples with drooping eyelids and unresponsive limbs.

Darker still, some authorities warn of madness. As Carl Jung put it, advanced yoga can “let loose a flood of sufferings of which no sane person ever dreamed.” Many yoga books cite Jung approvingly but always seem to miss that quote. Even so, it represented his considered opinion after two decades of study and reflection.

Overall, the risks and benefits turned out to be far greater than anything I ever imagined. Yoga can kill and maim—or save your life and make you feel like a god. That’s quite a range. In comparison, it makes most other sports and exercises seem like child’s play.

My research has prompted me to change my own routine. I have deemphasized or dropped certain poses, added others, and in general now handle yoga with much greater care. I hope you benefit, too.

I see this book as similar to informed consent—the information that the subjects of medical experiments and novel treatments are given to make sure they understand the stakes, pro and con.

To me, the benefits unquestionably outweigh the risks. The discipline on balance does more good than harm. Still, yoga makes sense only if done intelligently so as to limit the degree of personal danger. I’m convinced that even modest precautions will avert waves of pain, remorse, grief, and disability.

The heroes of this book are the hundreds of scientists and physicians who toiled inconspicuously over the decades to uncover the truth despite the obstcenter1es of scarce funding and institutional apathy. Their early inquiries not only began the process of illuminating yoga but, as it turns out, produced a remarkable side effect. They helped transform the nature of the discipline.

Yoga at the start was an obscure cult steeped in magic and eroticism. At the end, it fixated on health and fitness.

To my surprise, it turned out that science played an important role in the modernization. As investigators began to show how the ostensible wonders of yoga had natural explanations, the discipline worked hard to reinvent itself. A new generation of gurus downplayed the rapturous and the miraculous for a focus on material well-being. In essence, they turned yoga on its head by elevating the physical over the spiritual, helping create the secular discipline now practiced around the globe.

The first chapter details this upheaval. The tale is important not only for revealing the origins of the health agenda but for introducing main characters and themes. For instance, it turns out that a number of yoga miracles—if demonstrably untrue—nonetheless involve major alterations of physiology that can produce a wealth of real benefits. They can lift moods. They can fight heart disease. The newest research indicates that they may even slow the body’s biological clock.

Not that science has all the answers.

To the contrary, the investigation of the discipline began in response to an astonishing spectcenter1e nearly two centuries ago that still poses a number of fundamental questions today.

The science of yoga does more than reveal secrets. It can also shed light on real mysteries.

R
anjit Singh was an ugly little man who liked to surround himself with beautiful women. In childhood, smallpox had taken his left eye and pitted his face. He was unlettered. But Singh built an empire through force of character, uniting the warring tribes of western India. He became maharajah of the Punjab and amassed great wealth, including the Koh-i-Noor, at the time the world’s largest diamond. He could be generous. Though a Sikh, he gave a Hindu temple a ton of gold. Singh was a military genius and a humane despot. Most of all, he knew men.

In 1837, Singh learned that a wandering yogi had approached the court to propose live burial as a demonstration of his spiritual powers. The king agreed to sponsor the entombment but undertook a number of precautions. The holy man would be interred in a small building near the palace. In preparation, Singh had three of its four doorways sealed with bricks and mortar, turning the open structure into something resembling a jail—or, less optimistically, a crypt.

Military officers, as well as European doctors, watched as the yogi arranged himself into a sitting posture. It was most likely a Full Lotus, with legs crisscrossed and feet atop the thighs. One observer likened the pose to that of “a Hindoo idol.” Attendants then wrapped the yogi in white linen and placed him inside a wooden box. It rested in a shallow pit below the building’s floor. No dirt was applied because the yogi had expressed concern about ants attacking his body. The maharajah’s men did, however, secure the box with lock and key. They then padlocked the door at the building’s entrance and erected a mud wall to seal off the improvised cell from the outside world.