Mindfulness – purposely bringing attention to our environment in the present moment – is a growing field. As medical schools, universities, and workplaces start to implement mindfulness classes, more and more studies show the benefits of it on wellness. However, most outcomes are self-reported and subjective. So what about the influence of mindfulness on biological markers? Although studies are limited, in 2016, Black and Slavich published the first systematic review of randomized controlled trials assessing the influence of mindfulness on inflammatory markers.
In this study, using the American Mindfulness Research Association’s publication database, authors pooled 4000 published journal articles from January 1966 to July 2015. The search terms were “immune”, “inflammation”, “cytokine”, “proinflammatory”, “biomarker”, “blood”, “saliva”, “urine”, “telomere”, and “infection”. The inclusion criteria were: 1) having a Randomized Controlled Trial (RCT) design, 2) the main intervention being mindfulness, 3) immune-related biomarker measured, and 4) English being the language of publication. Of the 4000 articles, 20 met the inclusion criteria and were included in the systematic review.
The total sample size was n=1602, with a mean sample size, for each study, of n=80 (range between 21-201). 60%-70% of participants in each study were females. The enrollment criteria for each study were heterogeneous, ranging from diseases (e.g.: ulcerative colitis, rheumatoid arthritis, HIV+), to risk factors (e.g.: aging, poor sleep, overweight) to social statuses (e.g.: older adults, employees).
The main outcomes were: a) circulating and stimulated inflammatory proteins, b) cellular transcription factors and gene expression, c) immune cell count, d) immune cell aging, and e) antibody response.
For most studies, the intervention consisted of weekly group-based classes on mindfulness, where participants learned and practiced mindfulness techniques. 8 out of the 20 studies added a meditation retreat to their intervention protocol.
Authors showed decreased levels of CRP and NF-kB transcription, whereas telomerase activity and CD4 T cell counts increased. No pooled estimations of those level changes were provided in the manuscript, which consists of a major flaw in this study.
Another major limitation of this study is the heterogeneity of populations and of outcomes. Furthermore, sample sizes were small and techniques of mindfulness were not described.
This study, despite its very preliminary results, shows promising avenues for treatment of certain conditions. With its limited side-effects and the active involvement of patients in their care, mindfulness represents an interesting treatment tool to add in the management of various hyperinflammatory conditions such as eczema, arthritis, IBS, and more! This study highlights the need for further investigations before mindfulness can be implemented as part of treatment for certain medical conditions.
Black DS, & Slavich GM. Mindfulness meditation and the immune system: a systematic review of randomized controlled trials. Annals of the New York Academy of Sciences. 2016; 1373(1): 13.
This article was written by Mélanie Leung, a medical student at McGill University and member of the Mindful Medical Learner Team.