University of California researchers report finding that faith, the use of prayer or meditation, and religion, provide protective health benefits for cancer survivors. For seven years, researchers monitored the heart-rate variability of 23 women breast cancer survivors. Heart-rate variability, the beat-to-beat changes in heart rate, of healthy people will vary depending on circumstance.

According to the explanation given by researchers, a higher heart-rate variability indicates flexibility in the body's ability to respond efficiently to stress and is considered to be a marker of good health. A more inflexible, monotonous heart rate is associated with cardiovascular disease, depression and anxiety, and mortality. The researchers discovered the women who used prayer or meditation to find comfort during moments of stress and women of strong religious faith, had significantly better heart-rate variability than women who did not identify themselves to any spiritual practices or religion.

Carissa Low, lead researcher stated, "These findings are consistent with an emerging literature on the beneficial impact of faith and spirituality on health."