Over the years, I’ve become more devout and more convinced that prayer can benefit my patients, who have often turned to me in times of crisis and despair. Increasingly, I have wanted to offer them the option of prayer.

But I was reluctant at first because I didn’t know what the patients and the medical community would think.

Then, a few years ago, one of my longtime patients, Mrs. Kelly, came to see me. I sensed that she might appreciate it if I prayed for her, but I was very unsure.

Still, as her visit drew to a close, I said, “Mrs. Kelly, I would like to pray with you, if that’s okay.”

She agreed, and I said a simple prayer. Afterward, she started to cry. I worried that I had offended her.

“No one has prayed for me for 40 years,” Mrs. Kelly said. “It felt so good, you can pray for me every time I come.”

After that, I began offering my patients prayer in addition to my cardiology treatment. I discovered that they usually welcomed the prayer. Their anxiety disappeared, they were calmer, and they were even more receptive to my suggestions that they live a healthier lifestyle.

Before long, I realized I could see the positive results in their examinations and lab tests as well.

Was this divine intervention? Or was it simply the power of positive thinking? No matter what you believe, there is a growing body of scientific research that demonstrates prayer can have a positive effect on health.

One of the most common theories for the power of prayer is that the act of praying relieves stress, which is a key factor in the development of heart disease.

When you are under stress, your body releases hormones, including adrenaline and cortisol, to deal with it. These hormones increase your heart rate and blood pressure. Over time, they can result in an increase in abdominal fat as well.

These factors set the stage for coronary artery disease. Studies have found over and over again that the act of praying induces a calm state, which can make these hormones dissipate.

But it’s not only direct prayer that works: Studies are also indicating that prayer can be beneficial even when it’s indirect. This is known as intercessory prayer, which refers to the act of being prayed for by someone else.

One study conducted at San Francisco General Hospital looked at the effect of prayer on 393 cardiac patients. The patients were divided into two groups. Although both groups were told that people were praying for them, in fact, prayers were being said for only one group.

This study, published in the Southern Medical Journal, found that the patients who were prayed for had more favorable outcomes, including fewer complications, fewer cases of pneumonia, and they required less drug treatment.

Another, more recent study done at Duke University Medical School looked at 150 cardiac patients who were admitted for coronary stenting. They were given the following nonmedical therapies: guided imagery, stress relaxation, healing touch, or intercessory prayer.

Researchers found that only the patients that were being prayed for had lower complication rates and a quicker recovery.