SUNDAY, Sept. 17 (HealthDay News) -- Whenever a loved one suffers a health crisis, well-wishers often pass on the heartfelt promise that they'll "pray for you."

In fact, so many people believe in the power of prayer that it's now caught the attention of scientific researchers.

"Praying for your health is one of the most common complementary treatments people do on their own," said Dr. Harold G. Koenig, co-director of the Center for Spirituality, Theology and Health at Duke University Medical Center. "About 90 percent of Americans pray at some point in their lives, and when they're under stress, such as when they're sick, they're even more likely to pray."

More than one-third of people surveyed in a recent study published in the Archives of Internal Medicine said they often turned to prayer when faced with health concerns. In the poll involving more than 2,000 Americans, 75 percent of those who prayed said they prayed for wellness, while 22 percent said they prayed for specific medical conditions.

Numerous randomized trials have been done to assess the effect of intercessory prayer on heart patients' health.

In one such study, neither patients nor the health-care providers had any idea who was being prayed for. The coronary-care unit patients didn't even know there was a study being conducted. And, those praying for the patients had never even met them.

The result: While those in the prayer group had about the same length of hospital stay, their overall health was slightly better than the group that didn't receive special prayers.

"Prayer may be an effective adjunct to standard medical care," wrote the authors of this 1999 study, also published in the Archives of Internal Medicine.

However, a more recent trial from the April 2006 issue of the American Heart Journal seemed to contradict these findings, suggesting that it's even possible for some harm to come from prayer.

In this study, which included 1,800 people scheduled for heart surgery, the group who knew they were receiving prayers developed more complications from the procedure, compared to those who had not been a focus of prayer. Additionally, this study found no benefit in the group that received prayers, but didn't know it.

But Koenig said there's a simple explanation why people might fare worse if they knew they were being prayed for in a study.

"These people got the news just before they went into surgery. They were given pieces of paper that said they'd be getting prayer, which may have made them think, 'Oh my God, what's wrong with me?' " Koenig explained. "That's a totally artificial situation. Normally, you have loved ones and friends praying for you and there's nothing negative in that situation."

This new study also points out the difficulty of trying to quantify the effects of prayer, said Koenig.

"Studies cannot prove that prayer does not work. We don't know any more about the efficacy of prayer after reading these studies and they shouldn't affect anyone's belief in prayer," he said.

With scant evidence to support prayer for healing, should doctors encourage the practice?

Clearly, many patients are reluctant to bring up the subject with their physicians. In one study, only 11 percent of people surveyed have mentioned prayer to their physicians. But, physicians may be more open to the subject than patients realize, particularly in serious medical situations.

In a study of doctors' attitudes toward prayer and spiritual behavior, almost 85 percent of physicians thought they should be aware of their patients' spiritual beliefs. Most doctors said they wouldn't pray with their patients even if they were dying, unless the patient specifically asked the doctor to pray with them. In that case, 77 percent of physicians were willing to pray for their patient.

The bottom line on prayer and health: If it's something you want to do and you feel it might be helpful, there's no reason you shouldn't do it.

"I think many people are convinced that prayer helps, otherwise I don't think they would do it. Some people are 'foxhole religious' types and prayer's almost a reaction or cry to the universe for help. But, many people do it because they've experienced benefit from it in the past," Koenig explained.

"So, if you have any inclination that prayer might work, do it," he said.

More information

For more research on spirituality and health, head to the U.S. National Center for Complementary and Alternative Medicine.

SOURCES: Harold G. Koenig, M.D., professor, psychiatry and behavioral sciences, also associate professor, medicine, and co-director, Center for Spirituality, Theology and Health, Duke University Medical Center, Durham, N.C; April 2006, American Heart Journal; Oct. 25, 1999, Dec. 8/22, 2003, April 26, 2004, Archives of Internal Medicine

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