Power of Prayer: What Happens to Your Brain When You Pray?

A doctor at a Philadelphia hospital says prayer is not a cure for cancer — but can sometimes be as important as science in helping patients heal.

Dr. Andrew Newberg of Thomas Jefferson Hospital has been studying the effect of prayer on the human brain for more than 20 years, injecting radioactive dye into subjects and watching what changes inside their heads when they pray.

"You can see it's all red here when the person is just at rest," said Newberg, pointing at a computer screen showing brain activity, "but you see it turns into these yellow colors when she's actually doing prayer." 

These changes, says Newberg, are signs of the power of prayer to heal. Said Newberg, "We see not only changes in the activity levels, but in different neurotransmitters, the chemicals in our brain."

Because the brain basic body functions like heart rate, blood pressure, and the immune system, he said, "there's evidence to show that by doing these practices, you can cause a lot of different changes all the way throughout the body, which could have a healing effect."

Skeptics say, however, that while the brain changes during payer, there is no proof that those changes create healing.

"Your brain changes when you eat chocolate," said Dr. Richard Sloan, author of "Blind Faith: The Unholy Alliance of Religion and Medicine. "The brain changes when anything happens … There's nothing special about showing brain changes when people pray."

Sloan says that while religion provides comfort to believers during times of stress, they "shouldn't practice religion because it's like some sort of cosmic vending machine in which you can deposit a coin to get a health benefit." 

Newberg, who directs the Myrna Brind Center of Investigative Medicine at Jefferson, thinks medicine and prayer should work hand in hand.

"As far as we know, it is not a cure for cancer," said Newberg. "It is not going to cure somebody of heart disease. We can't tell people to pray in order to get better — that doesn't really make sense. The reason that it works is because it is part of the person's belief system."

He said it was particularly "fun" to watch what happened inside the brains of a group of Franciscan nuns when they joined together in a meditative prayer. The area of the brain associated with the sense of self began to "shut down," according to Newberg.

"You become connected to God. You become connected to the world," he said. "Your self sort of goes away."