Does yoga reduce stress? Studies say it does
SCIENTISTS are getting close to proving what yogis have held to be true for centuries - yoga and meditation can ward off stress and disease.
Dr John Denninger, director of research at the Benson-Henry Institute for Mind Body Medicine at Massachusetts General Hospital at Harvard Medical School, is leading a five-year study on how the ancient practices affect genes and brain activity in the chronically stressed.
His latest work follows a study he and others published earlier this year showing how so-called mind-body techniques can switch on and off some genes linked to stress and immune function.
While hundreds of studies have been conducted on the mental-health benefits of yoga and meditation, they have tended to rely on blunt tools like participant questionnaires, as well as heart-rate and blood-pressure monitoring.
Only recently have neuro-imaging and genomics technologies used in Dr Denninger's latest studies allowed scientists to measure physiological changes in greater detail.
"There is a true biological effect," he said. "The kinds of things that happen when you meditate do have effects throughout the body, not just in the brain."
The science is advancing alongside a budding "mindfulness" movement, which includes meditation devotees such as Professor Bill George, board member of Goldman Sachs Group and Exxon Mobil, and comedian Jerry Seinfeld.
As a psychiatrist specialising in depression, Dr Denninger said he was attracted to mind-body medicine, pioneered in the late 1960s by Harvard professor Herbert Benson, as a possible way to prevent the onset of depression through stress reduction.
While treatment with pharmaceuticals is still essential, Dr Denninger sees yoga and meditation as useful additions to his medical arsenal.
The study published in May in the medical journal PloS One showed that one session of relaxation-response practice was enough to enhance the expression of genes involved in energy metabolism and insulin secretion, and reduce expression of genes linked to inflammatory response and stress. There was an effect even among novices.
Harvard isn't the only place where scientists have started examining the biology behind yoga.
In a study published last year, scientists at the University of California at Los Angeles and Nobel Prize-winning researcher Elizabeth Blackburn found that 12 minutes of daily yoga meditation for eight weeks increased telomerase activity by 43 per cent, suggesting an improvement in stress-induced ageing.