The Effect of Meditation on Health: a Metasynthesis of Randomized Controlled Trials

Objectives Meta-analyses have identified benefits of meditation for many specific health outcomes, including depression, diabetes, and smoking. However, the meditation literature lacks a comprehensive synthesis of meta-analyses on meditation-health effects. This study used metasynthesis (i.e., second-order meta-analysis) to derive a comprehensive estimate of the effect of meditation on health. Methods Twenty-eight meta-analyses of randomized controlled trials, which collectively provided 404 meta-analytic effects from over 31,000 participants, met criteria for inclusion. Information on the type of health outcome, meditation, and sample as well as the methodological quality and average intervention length was extracted from each meta-analysis. An unweighted model was used to aggregate data. Results A medium-sized effect of meditation on health was obtained after aggregating across meta-analyses (d = 0.50, 95% CI [0.42, 0.58]). The effect of meditation was stronger when examining yoga than mindfulness or focused attention, was similar for mental and physical health, and was stronger in younger samples, higher quality studies, and studies with longer interventions. Conclusions This metasynthesis provides among the most compelling evidence to date that meditation benefits health. Nonetheless, current estimates of meditation-health effects may be inflated as a result of publication bias, low quality studies, and use of inactive control conditions.