(CBS) Religious people take on faith the healing power of prayer - on today's National Day of Prayer as on other days. And even hard-nosed doctors who have studied spirituality say science supports the belief that prayer brings health benefits - though not necessarily because God is listening.
Several studies have linked prayer to better health. A 2001 study showed that reciting rosary prayers or yoga mantras can enhance heart rhythm and breathing, and a 2011 study published in the Journal of Behavioral Medicine linked prayer to pain relief.
Research has also shown that the death rate of people who attend church regularly is about 30 percent lower than that among people who spend their Sundays doing something else, according to Dr. Lynda Powell, chairman of preventive medicine at Rush University Medical Center in Chicago.
What explains churchgoers' lower death rate? Is it because God smiles on the faithful?
Science has nothing to say on that question. But Dr. Powell, a leading researcher on spirituality and health, has identified health-promoting outlooks and behaviors that are common to all major religions.
"We studied Catholics, Prostestants, Muslims, Jews, Buddhists, and Hindus," Dr. Powell told CBS News. "We were asking what it is about their daily life that might serve to protect them. And all these people tended to pray or chant a mantra and take pauses throughout the day."
Those brief pauses - which some of the people she studied took up to 30 times each day - seem to lower blood levels of the stress hormones cortisol and noradrenalin, which have a corrosive effect on the body.
"Envision the body like a balloon," Dr. Powell explained. "The balloon is deflated in the morning. But as people go through they day, stress causes the release of these stress hormones, and that causes the balloon to inflate. But when people pause and take a deep breath, it deflates the balloon a bit."
There are also health benefits to other spiritual practices, including a willingness to forgive oneself and others.Dr. Powell said she isn't a religious person. But when it comes to the benefits of prayer and forgiveness, she's a big believer.