Exploring the boundaries between epigenetics and religiosity/spirituality: a systematic review.

BACKGROUND

Associations between religiosity/spirituality (R/S) and health are well documented, but underlying mechanisms remain poorly understood. This review examined epigenetic and related molecular pathways that may underlie these associations.

METHODS

EMBASE, PubMed, Web of Science, and Scopus were searched through 8 January 2025. Eligible studies assessed at least one R/S variable, construct, or intervention and gene-expression-related outcomes, including DNA methylation (DNAm), histone modifications, microRNAs, noncoding RNAs, or protein-level changes. Results were narratively synthesized. Risk of bias was assessed using Joanna Briggs Institute tools.

RESULTS

Thirty-six studies were included, totaling 43,671 participants. Nineteen were cross-sectional, 22 were conducted in the United States, 23 involved community populations, and 10 included clinical samples. Overall, 39 instruments or measurement approaches assessed R/S. Outcomes included inflammatory, stress-related, lipid-related, and gene-regulatory markers, including C-reactive protein (CRP), interleukin-6, cortisol, lipid profile, DNAm, and messenger RNA. Findings were heterogeneous, with consistent inverse associations for CRP and a tendency toward lower cortisol with higher R/S, while other outcomes were mixed.

DISCUSSION: The evidence suggests a potential beneficial epigenetics influence of R/S. However, methodological weaknesses, heterogeneity, limited longitudinal evidence, and small samples limit interpretation. Future studies require prospective designs, standardized measures, large samples, and confounding control.

PROTOCOL REGISTRATION: www.crd.york.ac.uk/prospero identifier is CRD42022327728.