Much has changed since physician Dean Ornish included yoga in his groundbreaking protocol for preventing, treating, and reversing heart disease more than three decades ago. Back then, the idea of integrating yoga with modern medicine was seen as far-out.

Today’s picture is very different: As yoga has become an increasingly integral part of 21st-century life, scientists, armed with new tools that allow them to look ever deeper into the body, have been turning their attention to what happens physiologically when we practice yoga—not just asana but also pranayama and meditation. These physicians, neuroscientists, psychologists, and other researchers are uncovering fascinating evidence of how the practice affects us mentally and physically and may help to prevent and assist in the treatment of a number of the most common ailments that jeopardize our vitality and shorten our lives.

Dozens of yoga studies are under way at medical institutions around the country, including Duke, Harvard, and the University of California at San Francisco. Some of the research is funded by the National Institutes of Health. More studies are on the way, thanks in part to the work of researchers at the Institute for Extraordinary Living at the Kripalu Center for Yoga and Health, one of the first US research institutes to focus exclusively on yoga. And in India, scientist Shirley Telles heads up Patanjali Yogpeeth Research Foundation, which is spearheading studies large and small.

While studies of yoga’s impact on health are at an all-time high, experts say that much of the research is still in the early stages. But the quality is improving, says Sat Bir Khalsa, a Harvard neuroscientist who has studied yoga’s health effects for 12 years. It’s likely, he says, that the next decade will teach us even more about what yoga can do for our minds and bodies. In the meantime, the patterns beginning to emerge suggest that what we know about how yoga keeps us well may be just the tip of the iceberg.

1. Pain Reliever

Yoga shows promise as a treatment for relieving certain kinds of chronic pain. When German researchers compared Iyengar Yoga with a self-care exercise program among people with chronic neck pain, they found that yoga reduced pain scores by more than half. Examining yoga’s effects on a different kind of chronic pain, UCLA researchers studied young women suffering from rheumatoid arthritis, an often debilitating autoimmune disorder in which the immune system attacks the lining of the joints. About half of those who took part in a six-week Iyengar Yoga program reported improvements in measures of pain, as well as in anxiety and depression.

2. Yes, You Can!

Kim Innes, a Kundalini Yoga practitioner and a clinical associate professor at the University of Virginia, recently published a study on how yoga may benefit people who have a variety of health risk factors, including being overweight, sedentary, and at risk for type 2 diabetes. Forty-two people who had not practiced yoga within the previous year took part in an eight-week gentle Iyengar Yoga program; at the end of the program, more than 80 percent reported that they felt calmer and had better overall physical functioning. “Yoga is very accessible,” Innes says. “Participants in our trials, even those who thought they ‘could not do yoga,’ noted benefits even after the first session. My belief is that once people are exposed to gentle yoga practice with an experienced yoga therapist, they will likely become hooked very quickly.”

3. Ray of Light

Much attention has been given to yoga’s potential effect on the persistent dark fog of depression. Lisa Uebelacker, a psychologist at Brown University, got interested in examining yoga as a therapy for depression after studying and practicing mindfulness meditation. Because depressed people tend to be prone to rumination, Uebelacker suspected that seated meditation could be difficult for them to embrace. “I thought yoga might be an easier doorway, because of the movement,” she says. “It provides a different focus from worry about the future or regret about the past. It’s an opportunity to focus your attention somewhere else.” In a small study in 2007, UCLA researchers examined how yoga affected people who were clinically depressed and for whom antidepressants provided only partial relief. After eight weeks of practicing Iyengar Yoga three times a week, the patients reported significant decreases in both anxiety and depression. Uebelacker currently has a larger clinical trial under way that she hopes will provide a clearer picture of how yoga helps.

4. Happy Day

It’s taken the development of modern technologies like functional MRI screening to give scientists a glimpse of how yogic practices like asana and meditation affect the brain. “We now have a much deeper understanding of what happens in the brain during meditation,” says Khalsa. “Long-term practitioners see changes in brain structure that correlate with their being less reactive and less emotionally explosive. They don’t suffer to the same degree.” Scientists at the University of Wisconsin have shown that meditation increases the activity of the left prefrontal cortex—the area of the brain that’s associated with positive moods, equanimity, and emotional resilience. In other words, meditating regularly may help you weather life’s ups and downs with greater ease and feel happier in your daily life.

5. Stay Sharp

Asana, pranayama, and meditation all train you to fine-tune your attention, whether by syncing your breathing with movement, focusing on the subtleties of the breath, or letting go of distracting thoughts. Studies have shown that yogic practices such as these can help your brain work better. Recently, University of Illinois researchers found that immediately following a 20-minute hatha yoga session, study participants completed a set of mental challenges both faster and more accurately than they did after a brisk walk or a jog.

Researchers are in the earliest stages of examining whether yogic practices could also help stave off age-related cognitive decline. “The yogic practices that involve meditation would likely be the ones involved, because of the engagement of control of attention,” says Khalsa. Indeed, research has shown that parts of the cerebral cortex—an area of the brain associated with cognitive processing that becomes thinner with age—tend to be thicker in long-term meditators, suggesting that meditation could be a factor in preventing age-related thinning.

6. Maintenance Plan

A 2013 review of 17 clinical trials concluded that a regular yoga practice that includes pranayama and deep relaxation in Savasana (Corpse Pose), practiced for 60 minutes three times a week, is an effective tool for maintaining a healthy weight, particularly when home practice is part of the program.

7. Rest Easy

In our revved-up, always-on world, our bodies spend too much time in an overstimulated state, contributing to an epidemic of sleep problems. A recent Duke University analysis of the most rigorous studies done on yoga for psychiatric conditions found promising evidence that yoga can be helpful for treating sleep disorders. Asana can stretch and relax your muscles; breathing exercises can slow your heart rate to help prepare you for sleep; and regular meditation can keep you from getting tangled up in the worries that keep you from drifting off.

8. Better Sex

In India, women who took part in a 12-week yoga camp reported improvements in several areas of sexuality, including desire, orgasm, and overall satisfaction. Yoga (like other exercise) increases blood flow and circulation throughout the body, including the genitals. Some researchers think yoga may also boost libido by helping practitioners feel more in tune with their bodies.

9. Cool Inflammation

We’re used to thinking of inflammation as a response that kicks in after a bang on the shin. But increasing evidence shows that the body’s inflammatory response can also be triggered in more chronic ways by factors including stress and a sedentary lifestyle. And a chronic state of inflammation can raise your risk for disease.

Researchers at Ohio State University found that a group of regular yoga practitioners (who practiced once or twice a week for at least three years) had much lower blood levels of an inflammation-promoting immune cell called IL-6 than a group new to yoga. And when the two groups were exposed to stressful situations, the more seasoned practitioners showed smaller spikes of IL-6 in response. According to the study’s lead author, Janice Kiecolt-Glaser, the more experienced practitioners went into the study with lower levels of inflammation than the novices, and they also showed lower inflammatory responses to stress, pointing to the conclusion that the benefits of a regular yoga practice compound over time.

10. Younger-Looking DNA

While the fountain of youth remains a myth, recent studies suggest that yoga and meditation may be associated with cellular changes that affect the body’s aging process. Each of our cells includes structures called telomeres, bits of DNA at the end of chromosomes that get shorter each time a cell divides. When telomeres get too short, the cells can no longer divide and they die. Yoga, it seems, may help to preserve their length. Men with prostate cancer who took part in a version of the Ornish healthy lifestyle program, which included an hour a day of yoga, six days a week, showed a 30 percent jump in the activity of a key telomere-preserving enzyme called telomerase. In another study, stressed care-givers who took part in a Kundalini Yoga meditation and chanting practice called Kirtan Kriya had a 39 per-cent increase in telomerase activity, compared with people who simply listened to relaxing music.

11. Immune Activity

Many studies have suggested that yoga can fortify the body’s ability to ward off illnesses. Now one of the first studies to look at how yoga affects genes indicates that a two-hour program of gentle asana, meditation, and breathing exercises alters the expression of dozens of immune-related genes in blood cells. It’s not clear how the genetic changes observed in this study might support the immune system. But the study provides striking evidence that yoga can affect gene expression—big news that suggests yoga may have the potential to influence how strongly the genes you’re born with affect your health.

12. Your Spine on Yoga

Taiwanese researchers scanned the vertebral disks of a group of yoga teachers and compared them with scans of healthy, similar-aged volunteers. The yoga teachers’ disks showed less evidence of the degeneration that typically occurs with age. One possible reason, researchers speculate, has to do with the way spinal disks are nourished. Nutrients migrate from blood vessels through the tough outer layer of the disk; bending and flexing may help push more nutrients through this outer layer and into the disks, keeping them healthier.

13. Keep Your Heart Healthy

Despite advances in both prevention and treatment, heart disease remains the no. 1 killer of both men and women in the United States. Its development is influenced by high blood pressure, high cholesterol, high blood sugar, and a sedentary lifestyle—all of which can potentially be reduced by yoga. Dozens of studies have helped convince cardiac experts that yoga and meditation may help reduce many of the major risk factors for heart disease; in fact, a review of no fewer than 70 studies concluded that yoga shows promise as a safe, effective way to boost heart health. In a study this year by researchers at the University of Kansas Medical Center, subjects who participated in twice-weekly sessions of Iyengar Yoga (including pranayama as well as asana) significantly cut the frequency of episodes of atrial fibrillation, a serious heart-rhythm disorder that increases the risk of strokes and can lead to heart failure.

14. Joint Support

By gently taking joints—ankles, knees, hips, shoulders—through their range of motion, asana helps keep them lubricated, which researchers say may help keep you moving freely in athletic and everyday pursuits as you age.

15. Watch Your Back

Some 60 to 80 percent of us suffer from low-back pain, and there’s no one-size-fits-all treatment. But there’s good evidence that yoga can help resolve certain types of back troubles. In one of the strongest studies, researchers at Group Health Research Institute in Seattle worked with more than 200 people with persistent lower-back pain. Some were taught yoga poses; the others took a stretching class or were given a self-care book. At the end of the study, those who took yoga and stretching classes reported less pain and better functioning, benefits that lasted for several months. Another study of 90 people with chronic low-back pain found that those who practiced Iyengar Yoga showed significantly less disability and pain after six months.

16. Control Blood Pressure

One-fifth of those who have high blood pressure don’t know it. And many who do struggle with the side effects of long-term medication. Yoga and meditation, by slowing the heart rate and inducing the relaxation response, may help bring blood pressure down to safer levels. Researchers at the University of Pennsylvania recently conducted one of the first randomized, controlled trials of yoga for blood pressure. They found that 12 weeks of Iyengar Yoga reduced blood pressure as well as or better than the control condition of nutrition and weight-loss education. (If you have high blood pressure, consult with your doctor and make sure it’s under control before you practice inversions.)

17. Down With Diabetes

Researchers at the University of Pittsburgh School of Medicine found that adults at risk for type 2 diabetes who did yoga twice a week for three months showed a reduction in risk factors including weight and blood pressure. While the study was small, all who began the program stuck with it throughout the study, and 99 percent reported satisfaction with the practice. In particular, they reported that they liked the gentle approach and the support of the group. If larger, future studies show similar results, the researchers say, yoga could gain credence as a viable way of helping people stave off the disease.

18. News Flash

Many women have turned to yoga to help them cope with the symptoms of menopause, from hot flashes to sleep disturbances to mood swings. A recent analysis of the most rigorous studies of yoga and menopause found evidence that yoga—which included asana and meditation—helps with the psychological symptoms of menopause, such as depression, anxiety, and insomnia. In one randomized controlled trial, Brazilian researchers examined how yoga affected insomnia symptoms in a group of 44 postmenopausal women. Compared with women who did passive stretching, the yoga practitioners showed a big drop in incidence of insomnia. Other, more preliminary research has suggested that yoga may also help to reduce hot flashes and memory problems, too.

19. Emotional Rescue

Recent studies have suggested that exercise is linked with increased levels of a brain chemical called gamma-aminobutyric acid (GABA), which is associated with positive mood and a sense of well-being. It turns out that Iyengar Yoga can also increase the levels of this chemical in the brain, more so than walking, according to a Boston University study. In another study, a group of women who were experiencing emotional distress took part in two 90-minute Iyengar Yoga classes a week for three months. By the end of the study, self-reported anxiety scores in the group had dropped, and measures of overall well-being went up.

20. Power Source

If you’ve felt the thrill of discovering you can hold Chaturanga for longer and longer periods, you’ve experienced how yoga strengthens your muscles. Standing poses, inversions, and other asanas challenge muscles to lift and move the weight of your body. Your muscles respond by growing new fibers, so that they become thicker and stronger—the better to help you lift heavy grocery bags, kids, or yourself into Handstand, and to maintain fitness and function throughout your lifetime.

21. Balancing Act

When you were a kid, your day included activities that tested your balance—walking along curbs, hopping on your skateboard. But when you spend more time driving and sitting at a desk than in activities that challenge your balance, you can lose touch with the body’s magical ability to teeter back and forth and remain upright. Balance poses are a core part of asana practice, and they’re even more important for older adults. Better balance can be crucial to preserving independence, and can even be lifesaving—falls are the leading cause of injury-related death in people over 65.