The health benefits of yoga: A scientific perspective
When Science Met Nature…
Jessica’s Science Blog – 08.04.16
The first time you try yoga just might be the first day of the rest of your life. Many people know that yoga helps alleviate physical ailments such as back pain, but the science of yoga and meditation has begun to reveal much broader health benefits. In recent years, scientists have identified a constellation of yoga health benefits that runs the gamut from cognitive and emotional functioning to physiological effects.
In a 2016 research study of older adults published in the Journal of Alzheimer’s Disease, 12 weeks of yoga and meditation led to improvements in mood, coping skills, anxiety, depression, and visual and spatial memory. Participants in a control group doing memory exercises did not experience these improvements. The UCLA researchers, who published the study, used functional MRI to show actual changes in the brains’ neural networks after the 12 weeks of yoga and meditation.
But how? Some tantalizing mechanisms have been suggested: regular meditation and yoga practice may actually reduce inflammation and increase the production of a protein that promotes neural connectivity. Neuroplasticity, or the idea that the brain can remodel or change its neural networks through the mindful practice of yoga, is an old concept dating back almost 2,000 years to ancient texts compiled in the Yoga Sutra.
if yoga can change our brains, can it also help reduce stress and ward of disease? As it turns out, chronic stress and disease are linked together like partners dancing the tango. Some of the most classic research on this topic comes to us from Dr. Robert Sapolsky, a renowned behavioral endocrinologist who studied cortisol and behavior in wild baboons. As Sapolsky explained in his book, Why Zebras Don’t Get Ulcers, prolonged stress leads to physiological changes, particularly in the immune system: when we experience high stress hormone levels over long periods of time, our ability to fight off disease becomes weakened. The so-called stress diseases of the Western World, such as ulcers, anxiety, depression, and even heart disease, may be explained by this simple biological truth.
One of the ways in which yoga reduces stress is through deep relaxation. According to a 2013 article by the medical editor for Yoga Journal, Dr. Timothy McCall, research from the Swami Vivekananda Yoga Research Foundation in India suggests that, although yogis could achieve relaxation via meditation and breathing exercises alone, a deeper form of relaxation was attained when they front-loaded restorative practices with active ones. This works because of a basic principle of our autonomic nervous systems; Active practices stimulate the sympathetic nervous system, which increases heart rate and blood pressure, whereas restorative practices activate the parasympathetic nervous system, which slows the heart and aids in digestion.
Deep relaxation is one thing, but what about yoga’s effects on overall health and autonomic function? Is there strong evidence for a positive association between yoga and a person’s autonomic health and aerobic fitness? Well, one such indicator is known as heart rate variability or HRV. In a recent review of the literature looking at whether yoga can increase HRV, authors concluded that, while there is some tentative support for this notion, more rigorous studies with standardized research methods and measurements are needed to properly test this hypothesis.
Other clinical evidence points to the ability of yoga and meditation to reduce, if not reverse, many of the health costs brought about by a lifestyle once marked by chronic stress. Western medicine has already begun amassing a robust body of evidence supporting the physiological, emotional, and cognitive benefits of regular yoga, such as stress reduction, enhanced immunity, lowered blood sugar, and increased strength and flexibility, among other benefits.
The yoga revolution in America continues. Hopefully, one day we will receive treatment-based prescriptions as well as preventative care directives from our physicians to practice yoga. As David Rachford, a navy veteran who was prescribed yoga as treatment for pain management in one outpatient care center, put so eloquently, “My yoga practice became the base that restored my health, taking me from smoking, having high blood pressure, and being overweight and pre-diabetic to being fit, active, and a picture of health. I’ve lost 50 pounds, my blood pressure is normal, and I can jog and hike without pain.”
Breath in – I know I’m breathing in. Breath out – I know I’m breathing out. Om shanti.
Listen to the peace mantra for Hatha Yoga