title: The effects of mind-body therapies on the immune system: meta-analysis.
abstract: OBJECTIVE
  Psychological and health-restorative benefits of mind-body therapies have been investigated, but their impact on the immune system remain less defined.
  
  
  OBJECTIVE
  To conduct the first comprehensive review of available controlled trial evidence to evaluate the effects of mind-body therapies on the immune system, focusing on markers of inflammation and anti-viral related immune responses.
  
  
  METHODS
  Data sources included MEDLINE, CINAHL, SPORTDiscus, and PsycINFO through September 1, 2013. Randomized controlled trials published in English evaluating at least four weeks of Tai Chi, Qi Gong, meditation, or Yoga that reported immune outcome measures were selected. Studies were synthesized separately by inflammatory (n = 18), anti-viral related immunity (n = 7), and enumerative (n = 14) outcomes measures. We performed random-effects meta-analyses using standardized mean difference when appropriate.
  
  
  RESULTS
  Thirty-four studies published in 39 articles (total 2, 219 participants) met inclusion criteria. For inflammatory measures, after 7 to 16 weeks of mind-body intervention, there was a moderate effect on reduction of C-reactive protein (effect size [ES], 0.58; 95% confidence interval [CI], 0.04 to 1.12), a small but not statistically significant reduction of interleukin-6 (ES, 0.35; 95% CI, -0.04 to 0.75), and negligible effect on tumor necrosis factor-α (ES, 0.21; 95% CI, -0.15 to 0.58). For anti-viral related immune and enumerative measures, there were negligible effects on CD4 counts (ES, 0.15; 95% CI, -0.04 to 0.34) and natural killer cell counts (ES, 0.12, 95% CI -0.21 to 0.45). Some evidence indicated mind-body therapies increase immune responses to vaccination.
  
  
  CONCLUSIONS
  Mind-body therapies reduce markers of inflammation and influence virus-specific immune responses to vaccination despite minimal evidence suggesting effects on resting anti-viral or enumerative measures. These immunomodulatory effects, albeit incomplete, warrant further methodologically rigorous studies to determine the clinical implications of these findings for inflammatory and infectious disease outcomes.
authors.affiliation: Center for Integrative Medicine, Division of Rheumatology, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts, United States of America.
authors.forename: Nani
authors.initials: N
authors.lastname: Morgan
authors.affiliation: Cousins Center for Psychoneuroimmunology, UCLA Semel Institute for Neuroscience, University of California Los Angeles, Los Angeles, California, United States of America.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Irwin
authors.affiliation: Nutrition/Infection Unit, Department of Public Health and Community Medicine, Tufts University School of Medicine, Boston, Massachusetts, United States of America.
authors.forename: Mei
authors.initials: M
authors.lastname: Chung
authors.affiliation: Center for Integrative Medicine, Division of Rheumatology, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts, United States of America.
authors.forename: Chenchen
authors.initials: C
authors.lastname: Wang
mesh_terms: D002097:C-Reactive Protein / Q000276:immunology / Q000378:metabolism; D018791:CD4 Lymphocyte Count; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000276:immunology / Q000628:therapy; D015850:Interleukin-6 / Q000097:blood / Q000276:immunology; D016239:MEDLINE; D016032:Randomized Controlled Trials as Topic; D026302:Tai Ji / Q000379:methods*; D014409:Tumor Necrosis Factor-alpha / Q000097:blood / Q000276:immunology; D014777:Virus Diseases / Q000097:blood / Q000276:immunology / Q000628:therapy
chemical_list: C508600:IL6 protein, human; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein