Can praying be good for your health? A decade ago, most doctors and scientists would have dismissed any connection between prayer and medicine. However, recent studies drawing a positive connection between faith and healing have sparked new debate in the United States over the issue.

A recent Gallup poll shows that 95 percent of the population of the United States believes in God, and nearly 80 percent of people over 65-years-old are members of a church.

A number of studies have shown that individuals who pray regularly and attend religious services stay healthier and live longer than those who rarely or never go to a church, synagogue or mosque.

Duke University recently released a study of 4,000 women and men of different faiths. All the participants were 65 or older.

The study found that the relative risk of dying was 46 percent lower for those who frequently attend religious services.

A study by the same group says those who pray regularly have significantly lower blood pressure than those who do not.

It also found that those who attend religious services have healthier immune systems.

Dr. Harold Koenig of Duke University is the director and founder of the Center for the Study of Religion, Spirituality and Health.

Dr. Koenig says, when he first opened the center in the 1990's he was afraid, as he puts it, "of being run out of town for practicing voodoo medicine."

But he says his own research and recent studies by other universities have convinced him that prayer, much like exercise and diet, has a connection with better health.

"A religion-medical connection is not new or unnatural," he said. "Many patients are religious, and use it to cope with illness. Religion is related to mental health, social support and health behaviors. Better mental health, in turn, better social support, better health behaviors are related to better physical health. Thus religion should be related to physical health, and when you examine it, it is."

Studies at several medical centers conclude that prayer and faith help in the recovery from heart attacks, drug addiction, stroke, alcoholism and depression.

At the University of Miami, research showed AIDS patients who became long-term survivors were more frequently engaged in religious worship and involved in volunteer work.

Cynthia Cohen is a senior researcher at the Kennedy Institute of Ethics at Georgetown University in Washington.

"So far, the studies seem to show that prayer, in particular, seems to work on some patients," said Ms. Cohen. "There are studies that show that prayer has apparently been associated with improved healthcare outcomes for a high proportion of patients in certain studies. However, there are other studies that show that prayer doesn't seem to have the same degree of effectiveness."

Dr. Richard Sloan is a professor of behavioral medicine at the College of Physicians and Surgeons at Columbia University in New York.

Dr. Sloan questions how the research linking prayer and good health is being done, and says evidence is not convincing.

"Most of those studies have significant methodological flaws, which render their conclusions wrong," he said. "Now, there are some relatively good studies recently. But by and large, the body of evidence is weak and inconclusive linking religion and health."

Dr. Sloan argues that involving physicians with a patient's religion could lead to ethical problems.

He says some doctors might treat patients differently because of their faith, or even attempt to convert them to a specific religion during a difficult time of life.

"The principal concern is a threat to the patient's religious freedom," said Mr. Sloan. "The patient should be as religious or not religious as they choose without interference from physicians. Physicians should not make recommendations that suggest to patients that they ought to behave in one way or another religiously, either more or less religiously. Patients ought to behave religiously, as they see fit, without interference from physicians. So there are substantial ethical questions raised by involving religion with medicine."

Also controversial is whether intercessory prayer or prayer seeking divine help to improve the health of others, actually works.

At nine medical centers around the country, hundreds of patients with severe heart problems participated in a survey of long distance healing.

The names of half the patients were given to Buddhist monks, Carmelite nuns, Sufi Muslims and Christian congregations who prayed for their recovery.

The results are expected to be released next month, but in a similar pilot survey prayer recipients had significantly fewer medical complications.