The effect of mindfulness-based interventions on immunity-related biomarkers: a comprehensive meta-analysis of randomised controlled trials

Abstract

One proposed pathway that mindfulness-based interventions (MBIs) may offer a salutogenic effect on somatic disorders is by enhancing immune function. As such, we conducted a meta-analysis of randomised controlled trials examining the effect of MBIs at post-intervention and follow-up for six immune-related biomarkers, including CD4+ cells, C-reactive protein, interleukin-6, nuclear factor-κB, telomere length, and telomerase activity. Potential studies were identified by searching ScienceDirect, Web of Science, Academic Search Complete, AMED, MEDLINE, PsycARTICLES, and PsycINFO. Searches returned 1959 studies, of which 48 (70 effects) were included (N = 4683). Pooled effect sizes indicated a reduction in C-reactive protein (SMCD = -.14, 95% CI [-.26 - -.01]) and interleukin-6 (SMCD = -.35, 95% CI [-.67 - -.03]), and an increase in CD4+ (SMCD = .09, 95% CI [-.05 - .22]), telomere length (SMCD = .12, 95% CI [.00 - .24]) and telomerase activity (SMCD = .81, 95% CI [.17 - 1.46]) at post-intervention. At follow-up, results showed a reduction in interleukin-6 (SMCD = -.13, 95% CI [-.29 - .03]) and C-reactive protein (SMCD = -.39, 95% CI [-.68 - -.10]) and increase in CD4+ (SMCD = .22, 95% CI [-.08 - .52]). Meta-regression results showed that some heterogeneity in effect size could be accounted for by intervention dosage, study population, and study design. Our findings quantify MBIs' potential for improving immune function and thus impacting somatic disorders.

Keywords: Biomarkers; C-reactive protein; CD4; CRP; IL-6; Immune function; Immunity; Inflammatory; Interleukin; MBCT; MBI; MBSR; Mindfulness; Mindfulness-based; Telomeres.