The Healing Power of Prayer

Arnold Tweed 

This story is not about surviving the physical ravages of disease, it is about mental and emotional survival. I am attaching Harold’s own account of his illness. It should be read in full and sympathetically because only someone who has walked that road can fully appreciate the emotional as well as the physical pain. (Go back one to Harold’s Story). Harold describes some of that, but he focuses more on the positive, on the comfort and hope that he drew from his family and his Christian faith. His is a story about hope, love and faith – and the healing power of prayer.

Modern scientific medicine has made such dramatic progress in treating and even eliminating disease that we tend to see treatment solely in terms of physical interventions: drugs, surgery, radiation, manipulation. The science of medicine dominates the field today; the art of medicine is seldom mentioned. This is a story about the subjective aspects of healing and the importance of mental, emotional and spiritual factors in illness. But being subjective does not put it beyond the scope of science. I approached this as a medical scientist and looked for empirical evidence for benefits. I found much more than I had expected.

First, a word of caution, please do not confuse the use of spiritual in this context with ‘spiritual healing’ cults. The world is awash with such cults; just Google ‘spiritual healer’ and you will be flooded. One cult, the Aetherius Society, claims that its founder, Dr. George King, was taught the arts of psychic healing by extraterrestrial beings. Aetherians and similar cults often claim to manipulate some sort of ubiquitous ‘spiritual energy’ by ‘contact healing’. A recent expose in the Toronto Star warned of the fraudulent nature of purported ‘healers’ (Mendleson 2015). Harold and I use spiritual in a very different sense – not as a substance or force to be manipulated – but as a personal conviction that there is a being, greater than us, who loves us and asks only for our love in return. Harold never expected to be healed by prayer; he prayed for the strength to endure his illness.

Prayer for health is more common than we suspect. A national survey in the U.S. in 1998 found that 35% prayed for some aspect of their health and two-thirds of those found prayer to be helpful (McCaffrey, Eisenberg et al. 2004). Most did not discuss prayer with their physicians. This suggests an interesting dichotomy in health care: patients consult their physicians for the medical aspects of care but not for their spiritual, emotional and mental needs.

The use of prayer as therapy is a very private and largely ignored practice. Prayer can be for the benefit of others or for self. The first is called intercessory prayer, prayer by an individual or group for the benefit of another. The second is petitionary prayer, prayer for oneself. Harold was the beneficiary of both. His church community prayed for him; and his sometimes anguished personal prayers are well described in his story.

Intercessory prayer has been studied empirically by several groups, probably because it lends itself to the rigidly controlled studies necessary to ensure scientific validity. Leanne Roberts (Hertford College, Oxford, UK) has published three Cochrane Reviews (latest 2009, Intercessory Prayer for the Alleviation of Ill Health) which have summarized by meta-analysis the Randomized Control Trials (RCTs) completed up to that date. Now this is a heavy dose of academic shop-talk so let me clarify the terminology. The Cochrane Database is a gold standard for evidence based medicine; Cochrane reviews are carefully edited and scientifically vetted. Meta-analysis is a statistical technique for combining the results of several studies. RCTs are the gold standard for medical research and are designed to measure the effect of one treatment, and one only, on a target outcome. In their latest review Roberts and Company combined ten RCTs by meta-analysis (7,646 patients). First, you might be surprised to hear that there have been ten scientifically valid studies of this subject. Second, you might not be too surprised to learn that the results were equivocal. What does that mean exactly? Well, some studies showed beneficial results, some did not, but the combined analysis did not reveal a statistically significant benefit. Not surprised?

Does that mean there is no value whatsoever to intercessory prayer? No one has yet considered that the main, and perhaps intended, benefit may be to the prayer group. Group prayer fosters group cohesion, common purpose, shared values and reinforces faith. It enfolds the object of the prayer into the nurturing bosom of the community and reinforces group identity for all. Group benefit and individual benefit are difficult to separate.

However, before reaching a final conclusion, consider this. An RCT performed by Olver and Dutney from the Royal Adelaide Hospital in Australia with 1000 patients, published in 2012, showed small but statistically significant benefits in spiritual, emotional and functional well-being in patients who were prayed for (Olver and Dutney 2012). Now are you surprised? I am amazed! The design of their RCT was technically called ‘double-blinded’, that is the patients were randomized to treatment (prayer) and control groups but were not told which group they were assigned to. The group who prayed, an external prayer group, was given details about the patients but not their identity. In other words, the prayer group was praying for someone, they didn’t know exactly who, who in turn didn’t know if they were or were not being prayed for. Sound ridiculous? Well, that’s what you have to do to meet the scientific rigor of an RCT. There must be something about intercessory prayer that works at some level to survive that amount of obfuscation. Perhaps this issue is just too complex for science and we should abandon scientific efforts to prove or disprove religion.

Petitionary prayer has not been as well studied. In large part this is because it is so subjective and private. Since belief in the efficacy of the prayer is integral to the effect, it is difficult to conceive a study design where subjects could be randomly assigned to treatment (prayer) and non-treatment groups. However, there is a huge literature on religion and health outcomes and most studies used a general classification of religion/spirituality (R/S) to cover all aspects of belief, ritual and prayer. The specific contribution of petitionary prayer is hidden in the whole. Two major reviews were published in 2015 with meta-analysis of literally hundreds of studies (Jim, Pustejovsky et al. 2015, Salsman, Pustejovsky et al. 2015). Overall they concluded that there was a positive benefit of R/S on several measures of patients’ physical and functional well-being, including their symptoms and mental health. Several studies reported increased tolerance to pain and improved function, even when intensity of pain was unchanged.

It is also interesting that there is a trend in the recent palliative care and oncology literature to separate spirituality from religion. Medical providers are appropriating spirituality and relocating it into the bio-medical and psycho-social fields of research. Spirituality is being reshaped to encompass considerations of self and relationships while shedding the dependency on religious beliefs. A brief quotation from a recent review may give you a flavor of this change: “A ‘spirit to spirit’ framework for spiritual care-giving respects individual personhood.” (Edwards, Pang et al. 2010) If you understand that please enlighten me by writing a commentary to this article.

Medical science has identified that the benefits of prayer are mainly on subjective outcomes and coping behaviours. Please note that, in all of the literature documenting the benefits of prayer, there are no scientifically valid studies that demonstrate prayer to be an effective substitute for medical treatment. The main reason that prayer is held in disdain by scientists and medical doctors is the exaggerated claims made by some, Christian Science foremost, that prayer can replace medical treatment. There is no credible evidence whatsoever for these claims. Prayer can be complementary to medical treatment but it is not a substitute. If you read Harold’s story you will see that replacing medical treatment with prayer never occurred to him, not even when his treatment was causing him more distress than his disease.

The physical benefits of prayer may be attributed to a phenomenon well known to medicine, the placebo effect. Henry K. Beecher, Professor of Anesthesiology at Harvard brought the placebo effect to public attention in 1955. Its most important application since has been as a sham treatment administered to the control group in placebo-controlled clinical studies. However, there is new interest in placebos as a therapeutic tool in their own right. This is summarized in a recent feature article in the National Geographic magazine (Vance 2016). A more scholarly review published in the NEJM in 2010 combined studies (again by meta-analysis) in which placebo-treated groups were compared to no-treatment groups. They concluded that placebo treatment had a significant benefit when the measured outcomes were subjective and patient-reported, such as pain and nausea (Hróbjartsson and Gøtzsche 2010). These articles support the hypothesis that placebos act by psychological mechanisms, perception and expectancy effects, and by triggering the release of endogenous hormones in the brain (endorphins and cannabinoids). The magnitude of the effects are still controversial but estimates range from 7-35%. Evidence is mounting that the placebo effect is part of a natural defence mechanism. Are the medical benefits of prayer a placebo effect? They have similarities, and may depend on the same mechanisms, but we wait confirmation from appropriately designed studies.

This brings us to our last consideration; is prayer a psychotherapeutic or spiritual exercise?  It may be both since those who pray with conviction experience both spiritual and physical benefits. Although the spiritual side is opaque to empiric methods of study, bits of the enigma, the physiological and psychological bits that can be measured, are emerging. Hans Lou and colleagues at Aarhus University, Denmark, have observed that meditation exercises (they studied Yoga Nidra meditation) were associated with activation patterns in specific areas of the brain that modulate self-awareness (Lou, Kjaer et al. 1999). The same may be true for prayer. This is a start in understanding the complex cognitive processes associated with prayer and meditation. But the spiritual realm remains impenetrable to our methods, though spiritual needs are still a reality in our lives. Fear, grief and despair are the constant companions of disease and are not comforted by tranquilizers. Prayer is not just the bridge to the spiritual domain, it links the physical and spiritual domains so that its benefits are experienced in both.

Spiritual needs are traditionally met within a religious framework and Harold’s story describes how he found spiritual comfort in prayer and scripture, within his Christian faith. Some recent literature suggests that spiritual needs can also be addressed outside of a religious context. This at least recognizes the existence of spiritual needs, especially for the elderly, sick and dying, but we wait to see how these alternative approaches will evolve. Spiritual needs aside, my reading has convinced me that prayer is a powerful adjunct to medical treatment and is probably underutilized. The medical literature confirms that prayer, when offered with conviction, improves patients’ outcomes. Since most patients do not discuss their religion with their doctors the medical profession’s indifference to prayer is understandable. This is the business of hospital chaplains, but doctors rarely speak to them either. Instead of “Integrative” health care we have partitioned health care. If prayer were offered as part of the treatment plan would patients feel better, recover faster, and use less fentanyl? This is a challenge that our modern “patients first” policy makers might consider.


Before closing this story I want to add a personal postscript. I wanted to write about Harold’s experience for several reasons. I knew that Harold was articulate and insightful and could help us, as sympathetic spectators, share his experience and better understand the physical and mental agony of life-threatening disease. Harold and I are medical school classmates and have been friends for more than fifty years. We share the same medical education and the same scientific view of medicine and disease. Harold is also deeply and sincerely religious, as his story proves. What we see clearly in this story, and others of similar genre, is that his religious and his medical responses to his illness were never in conflict. There is never a suggestion that his medical treatment was threatened by his religion nor that his religion was threatened by medical science. His spiritual needs and medical needs were in different spheres and required different therapy. Medicine and prayer were certainly compatible and may have been complimentary. Those who claim that science has conquered religion, or that religion denies science have a very shallow understanding of both. Harold’s story shows that science and religion are not at odds; they serve different needs towards the same end.



. “The Aetherius Society.” from

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Hróbjartsson, A. and P. C. Gøtzsche (2010). “Placebo interventions for all clinical conditions.” Cochrane Database of Systematic Reviews(1).

Jim, H. S., J. E. Pustejovsky, C. L. Park, S. C. Danhauer, A. C. Sherman, G. Fitchett, T. V. Merluzzi, A. R. Munoz, L. George, M. A. Snyder and J. M. Salsman (2015). “Religion, spirituality, and physical health in cancer patients: A meta-analysis.” Cancer 121(21): 3760-3768.

Lou, H. C., T. W. Kjaer, L. Friberg, G. Wildschiodtz, S. Holm and M. Nowak (1999). “A 15O-H2O PET study of meditation and the resting state of normal consciousness.” Hum Brain Mapp 7(2): 98-105.

McCaffrey, A. M., D. M. Eisenberg, A. T. Legedza, R. B. Davis and R. S. Phillips (2004). “Prayer for health concerns: results of a national survey on prevalence and patterns of use.” Arch Intern Med 164(8): 858-862.

Mendleson, R. (2015). Purported spiritual healers a wideapread problem. Toronto Star. Toronto.

Olver, I. N. and A. Dutney (2012). “A randomized, blinded study of the impact of intercessory prayer on spiritual well-being in patients with cancer.” Altern Ther Health Med 18(5): 18-27.

Salsman, J. M., J. E. Pustejovsky, H. S. Jim, A. R. Munoz, T. V. Merluzzi, L. George, C. L. Park, S. C. Danhauer, A. C. Sherman, M. A. Snyder and G. Fitchett (2015). “A meta-analytic approach to examining the correlation between religion/spirituality and mental health in cancer.” Cancer 121(21): 3769-3778.

Vance, E. (2016). “Mind Over Matter.” National Geographic 230(6): 30-55.

Author: Arnold Tweed

Retired anesthesiologist living in Toronto, Canada.