Efficacy of prayer in inducing immediate physiological changes: a systematic analysis of objective experiments.

Objectives: To assess the immediate impact of prayer on physiological state by systematically reviewing objective, controlled experimental studies in the literature.

Content: Experimental studies measuring objective physiological changes induced by prayer. Studies containing the keyword, "Prayer" anywhere in the title or abstract were curated from the following databases: Public/Publisher Medline (PubMed), Excerpta Medica Database (EMBASE) and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) in May 2019. Titles and abstracts were screened with the remaining 30 articles analyzed for inclusion. Only experimental studies were included.

Summary: Eight experimental studies were identified of which five investigated neurocognitive changes and three investigated systemic physiological changes during prayer. The five studies focusing on neuroactivity used functional MRI (fMRI), electroencephalography or SPECT imaging to obtain measurements. The remaining three studies analyzed an array of systemic physiological metrics, including blood pressure, heart rate, respiratory rate, peripheral resistance, baroreceptor sensitivity and/or cardiovascular rhythm variability during prayer. All studies aside from one saw objective changes during prayer. Neurocognitive changes were mainly associated with improved mental functioning, control and pain tolerance. Prayer was found to slow down physiological functions in two of the three vital-based studies, with the third reporting no change in physiological status. None of the studies measured blood marker changes.

Outlook: Experimental studies show prayer to induce healthy neurocognitive and physiological changes. Additional studies exploring objective measures from prayer are encouraged to provide practitioners with a more nuanced, scientific perspective when it comes to prescribing prayer as a complementary and alternative medicine (CAM) therapy.