It turns out peaceful thoughts really can influence our bodies, right down to the instructions we receive from our DNA, according to a new study.
Researchers for the study, published in the Public Library of Science, took blood samples from a group of 19 people who habitually meditated or prayed for years, and 19 others who never meditated.
The researchers ran genomic analyses of the blood and found that the meditating group suppressed more than twice the number of stress-related genes -- about 1,000 of them -- than the nonmeditating group.
The more these stress-related genes are expressed, the more the body will have a stress response like high blood pressure or inflammation. Over long periods of time, these stress responses can worsen high blood pressure, pain syndromes and other conditions.
The nonmeditating group then spent 10 minutes a day for eight weeks training in relaxation techniques that involved repeating a prayer, thought, sound, phrase or movement.
"What this does is to break the train of everyday thought -- you no longer have stressful thoughts and because of that the body is able to return to a healthy state," said Dr. Herbert Benson, director emeritus of the Benson-Henry Institute Mind/Body Medicine and an associate professor of medicine at Harvard Medical School.
By the end of the training, the novice meditating group was also suppressing stress-related genes, although at lower levels than those of the long-term meditating people.
"In the old days, we thought the mind didn't affect the body," Benson said. "In truth, it's breaking down the very old rule."
Indeed, fellow mind-body researchers are finding more evidence that meditation and spiritual practices can influence the body in elemental ways.
Dr. Dean Ornish, professor of medicine and founder of the Preventive Medicine Research Institute at the University of California at San Francisco, recently found a relationship between meditation and genes in prostate cancer.
"This is an important pilot study showing that meditation alone may favorably alter gene expression in whole blood," Ornish said. "These findings provide additional evidence to our recent study in PNAS [the Proceedings of the National Academy of Sciences] showing that meditation -- when combined with better nutrition and moderate exercise -- also favorably altered gene expression in prostate tissue."
But researchers warn that only preliminary steps have been taken toward establishing a connection between genes and meditation.
"It's on the limits of sensitivity of where we can go on genomics and proteomics," said Towia Libermann, co-author of the study and director of the Beth Israel Deaconess Medical Center Genomics Center in Boston. "We can't go into the brain itself, so a lot of what we do is going on in the blood."
That difficult step from brain to blood can make research to link meditation and genetics difficult.
"Things happen, and genes get turned on or turned off -- the genes make RNA, then the RNA makes proteins," said Dr. Charles Raison, clinical director of the Mind Body Program in the department of psychiatry and behavioral sciences at Emory University in Atlanta.
Raison said it is those final proteins in the process that have a significant effect on the body, and sometimes RNA doesn't end up making those proteins. Since genomic analysis measures only the RNA in the blood, it can't guarantee that RNA had a specific effect on the body.
"Not everything gets down to the business end of the gun," said Raison, who would also have liked to see more definition of what meditation means in the study as opposed to including any forms of repetitive prayer or yoga.
"Before you can say meditation does X, you've got to have a sense of what you mean by meditation," Raison said. "There's data to suggest that different meditative practices have different physical effects."
Yet Raison found the stress-related study intriguing.
"The study is consistent with other lines of emerging research, including ours," said Raison, who noted that lonely people have similar stress-related gene expression as the nonmeditating group in the study.
Another study by Dr. Richard Davidson at the University of Wisconsin found that people who were taught to meditate after a vaccination developed more antibodies to the virus than people who did not meditate afterward, Raison said.
According to Raison, it all falls in line with a modern-day misfiring of "danger pathways" that ramp up the body for fight or flight but also turn down the immune system and increase inflammation. If the meditation study proves correct, it could help stem these changes, along with exercise and diet.
"The gene changes have a lot to do with things that cause wear and tear on the body and the brain," said Raison. "Diabetes, cardiovascular disease, dementia, many diseases in the modern world are linked to this sort of wear and tear."
The researchers in the stress study would like to next focus on these types of individual diseases.
"If you're about to be torn apart by a tiger, these stress responses are adaptive," Raison said. "But if my boss is yelling at me every morning, these ancient responses are activated, but they are not useful."