Around the time of public enthusiasm in transcendental meditation — made famous by the Beatles going to India to study with a teacher called the Maharishi — there was also growing interest among researchers about the role of stress in the onset of cardiac disease. Herbert Benson, a cardiologist at Harvard Medical School began to research this area in the 1970s. He compared physiological measures of subjects who were meditating by concentrating on a mantra with those of a control group who were simply sitting quietly and found that the meditators showed marked decreases in their rates of metabolism and breathing, and had slower brain wave frequency than did the controls. Out of this initial work came the idea that meditation and perhaps other practices could somehow reverse the effects of “stress.”

Benson wanted to separate his work from any religious aspect of meditative practice and coined the term “the relaxation response” in his 1975 book of the same name. The relaxation response (RR) was found to have certain physiological characteristics, including decreased oxygen consumption, decreased carbon dioxide elimination, reduced blood pressure, reduced heart and respiration rate, prominent low frequency heart rate oscillations and changes in brain wave frequency. It was also accompanied by lower psychological distress. It became defined as a mind-body intervention that reversed the physiological effects of stress. There are many practices that can elicit an RR including: yoga, tai chi, various types of meditation, breathing exercises as well as biofeedback, Qi Gong, repetitive prayer and chanting, and progressive muscle relaxation.

Jon Kabat-Zin, a teacher of yoga and Buddhist meditation who held a degree in molecular biology from M.I.T., continued this work, teaching a form of Buddhist mindfulness meditation to various patient groups — a technique to achieve a state of RR. “Mindfulness stress reduction” has become a fairly well established aid in the treatment of a number of medical conditions, including depression and chronic pain conditions.

Striking results

Though the clinical effects of RR have been well established, we still lack any understanding of how it actually occurs. Here’s some recent research from the Benson Harvey Institute for Mind Body Medicine at Massachusetts Hospital. (Duseck JA et al. 2008; Genomic Counter Stress Changes Induced by the Relaxation Response. PLoS ONE3 (7) e2576.doi:10.1371/journal.pone.0002576 — accessed Dec. 3, 2009). The numbers are small and need further validation, but the results are striking. The researchers assembled a group of 19 people who had a daily practice that involved induction of an RR (group M). They matched 19 healthy controls (N1) who had no such practice and measured whole blood gene transcription profiles of both groups. They then provided the non RR group with 8 weeks of instruction in an RR technique and re-measured their transcription profile (N2).

They found statistically different expression of 2,209 genes in group M compared to group N1 — 1,275 were significantly unregulated and 934 genes were significantly down-regulated in M compared to N1. After group N1 received the RR training, 1,561 genes were found to be significantly differentially expressed after RR training — 874 were unregulated and 934 down-regulated. Further study found that 316 unregulated genes and 279 down-regulated genes were unique to the M group. Group M and group N2 had 260 genes unregulated and 169 genes down-regulated in common, apparently reflecting changes due to 8 weeks of RR practice.

Marked effects in weeks

The researchers note that there’s growing evidence that psychosocial stress can lead to wide disturbances at the cellular level, with increased oxidative stress and creating a pro-inflammatory milieu. Other work has shown changes in gene expression in peripheral leukocytes. Stress related changes in gene expression profile (GEP) have been demonstrated in healthy people. Previous work has found preliminary evidence of a similar GEP in a small group of practitioners of Qi Gong. The authors make the hypothesis that some of the changes in GEP seen with RR practice (short-term and long-term) may serve to ameliorate some of the stress induced changes in metabolic and inflammatory pathways. It’s striking that some of the changes appeared after only 8 weeks of RR practice.

Are the changes associated with the long-term RR practitioners somehow more important? How much RR is necessary for possible health benefits? At present, no one’s sure what to make of the gene expression products (proteins) that are now being widely examined in numerous studies. The overlap of patterns of GEP in this research is exciting and makes this area one to watch in coming years.