A recent article on PLoS One by a research team from the Benson-Henry Institute for Mind/Body Medicine at Massachusetts General Hospital (MGH) and the Genomics Center at Beth Israel Deaconess Medical Center (BIDMC) discusses the genetic effects of the relaxation response, a widespread bodily state induced by different mind-body techniques (such as meditation).
The original piece, Genomic Counter-Stress Changes Induced by the Relaxation Response, was published at PLoS One, and the findings are also discussed on ScienceDaily, Relaxation Response Can Influence Expression Of Stress-related Genes. It’s starting to be a bit of a refrain from genetics research, but it still bears repeating: the team is exploring a way that ‘changing the activity of the mind can alter the way basic genetic instructions are implemented,’ as Dr. Herbert Benson explained (in ScienceDaily).
The relaxation response is a bodily state, found in a variety of contexts, characterized by ‘decreased oxygen consumption, increased exhaled nitric oxide, and reduced psychological distress.’ Long-term effects of relaxation exercises include decreased oxygen intake and carbon dioxide elimination; reductions in blood pressure, heart and respiration rate; prominent low frequency heart rate oscillations; and some changes in cortical and subcortical brain regions, including increased thickness of the cortex (see NeuroReport and here also on the effect of meditation on aging).
For about three decades, dependable clinical studies have shown that relaxation response-producing exercises have a range of positive health benefits. What makes the current research distinctive (at least in my reading) is that the team traced this metabolic process to its genetic effects. As the authors write:
This study provides the first compelling evidence that the RR elicits specific gene expression changes in short-term and long-term practitioners. Our results suggest consistent and constitutive changes in gene expression resulting from RR may relate to long term physiological effects. Our study may stimulate new investigations into applying transcriptional profiling for accurately measuring RR and stress related responses in multiple disease settings.
The research team looked at long-term practitioners of mind-body exercises, a group of controls, and a third group that they trained in guided relaxation techniques, using 20 minutes each day of practice. The long-term practitioners were a diverse group, including practitioners of ‘Vipassna, mantra, mindfulness or transcendental meditation, breath focus, Kripalu or Kundalini Yoga, and repetitive prayer.’ I found the manipulation of the short-term group not terribly ambitious — many relaxation regimens around the world, including things like tai chi and compassion meditation, are much more demanding of practitioners. Admittedly, it’s hard to get experimental subjects to commit to arduous regimes; all the more reason to study naturally occurring ‘experiments’ (like the veteran practitioners). The groups weren’t terribly large either (around 60 subjects, in the first round, a bit over 70 all up), but the results were significant and very well documented, nonetheless.
A large number of genes seemed to be affected, with significant overlaps between the long-term and short-term practitioners. 260 genes were up-regulated and 168 genes were down-regulated in both the group of long-term practitioners and the group given short-term training. As the article reports: ‘they represent GEP changes characteristic of RR practice over at least 8 weeks.’ Some of the gene changes seem to cluster in genes expressed in hematopoietic cells, those linked to blood formation, and in genes linked to stress, oxidative metabolism, and primary metabolism. As the abstract reports: ‘gene ontology and gene set enrichment analyses revealed significant alterations in cellular metabolism, oxidative phosphorylation, generation of reactive oxygen species and response to oxidative stress.’
The researchers found that relaxation response was a kind of reversal of the genetic and cellular stress response. As the Discussion of the article suggests, ‘It is becoming increasingly clear that psychosocial stress can manifest as system-wide perturbations of cellular processes, generally increasing oxidative stress and promoting a pro-inflammatory milieu.’ In contrast, their analysis of relaxation response ‘reveals altered gene expression in specific functional groups which suggest a greater capacity to respond to oxidative stress and the associated cellular damage. Genes including COX7B, UQCRB and CASP2 change in opposite direction from that in the stress response.’
Jeffery Dusek, one of the authors explained to Science Daily, ‘Changes in the activation of these same genes have previously been seen in conditions such as post-traumatic stress disorder; but the relaxation-response-associated changes were the opposite of stress-associated changes and were much more pronounced in the long-term practitioners.’
Towia Libermann, director of the BIDMC Genomics, added: ‘This is the first comprehensive study of how the mind can affect gene expression, linking what has been looked on as a ‘soft’ science with the “hard” science of genomics.’ I don’t know about it being the ‘first,’ but it is a compelling exploration of the genetic mechanisms on the pointy end of cultural techniques for changing one’s own mental state.
There’s lots to like in this article, including the team’s recognition that the ‘relaxation response’ can be found in a host of different practices; the authors list ‘various forms of meditation, repetitive prayer, yoga, tai chi, breathing exercises, progressive muscle relaxation, biofeedback, guided imagery and Qi Gong.’ In addition, word repetition can induce the bodily response, so we might add chanting and Qawwali (Sufi devotional music).
I’m a bit less convinced by Benson’s assertion that ‘no matter which particular technique is used — different forms of meditation and yoga, breath focus, or repetitive prayer — the mechanism involved is the same.’ It might be. It might not be. Perhaps because I’m influenced by Gerald Edelman’s discussions of the variability of networks of brain stimulation (for example, in Wider Than the Sky: The Phenomenal Gift of Consciousness), I’d be surprised if variations in these techniques (such as those that use chanting or movement, for example) had no effect at all on the resulting neural, cellular, and perhaps even genetic processes. Although there’s some awareness of cultural variety, there’s no great respect for subtle differences among things like relaxation exercises that might shade some of the analysis. It’s hardly unusual; in a lot of the mind-body discussion, there’s a kind of assumption that all mind-body techniques are only superficially different. Oddly, this universalizing impulse is shared with a lot of New Age synthesis, which also seem to have a very ecumenical disregard for difference (sometimes to the chagrin of those they wish to embrace, such as various Indigenous religious representatives).
The researchers are also adding to our knowledge of variations in genetic expression among healthy subjects due to differences in habits, behaviour, or psychological training (as Libermann points out). Whether or not any of this can make a dent in the popular conception of genes as ‘blueprints’ or ‘programs’ that invariably get expressed in the mature organism, remains to be seen.
Update: find more on meditation on Neuroanthropology at Get into trance: Felicitas Goodman.
Jeffery A. Dusek, Hasan H. Otu, Ann L. Wohlhueter, Manoj Bhasin, Luiz F. Zerbini, Marie G. Joseph, Herbert Benson, and Towia A. Libermann. 2008. Genomic Counter-Stress Changes Induced by the Relaxation Response. PLoS One 3(7): e2576. doi:10.1371/journal.pone.0002576
Massachusetts General Hospital. 2008. Relaxation Response Can Influence Expression Of Stress-related Genes. ScienceDaily (July 3). Retrieved July 5, 2008, from http://www.sciencedaily.com /releases/2008/07/080701221501.htm
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