Stress is immunosuppressive. Research into this pernicious relationship between stress and disease has piqued interest in the ways that contemplative practices might positively influence the immune system. According to a large body of evidence, meditation appears to have profound effects on immune function in health and disease because of its ability to reduce stress.

Why does mindfulness reduce stress?

Two main facets of mindfulness meditation are equanimity and focused attention. Equanimity towards one’s thoughts decreases reactivity to stressful stimuli, and focused attention helps reduce the tendency towards the type of ruminative thinking that can activate the stress pathway. This relaxation response seems to have multiple effects on the body’s stress pathways. It enhances vagal tone, which in turn suppresses the activity of pro-inflammatory cytokines through the cholinergic anti-inflammatory pathway. It also reduces hypothalamic-pituitary-adrenal (HPA) activity in response to stressful situations, reducing basal levels of cortisol and meditating other downstream stress-related processes.

Evidence:

The majority of empirical evidence for meditation’s effect on the immune system support a protection and recovery model. Imagine being caught in a rainstorm without a raincoat and without a towel. In a torrent of stress, mindfulness is both the raincoat (preventative) and towel (palliative), so that, at the very least, stress is impeded in its course to reach downstream immune targets.  Some lines of evidence are described below:

1) Richard Davidson has conducted studies on the relationship between affective style and brain lateralization, and has found that people with positive affect have increased right prefrontal activation compared to people with negative affect. In a recent study, Davidson and colleagues found that after an eight-week mindfulness program, subjects demonstrated both increased left-PFC activation as well as an increased antibody production after administration of a flu vaccine, indicating an enhanced immune response.

2) Amount of meditation practice in a 6-week compassion meditation program was positively correlated with a decrease in stress-induced interleukin-6 (a pro-inflammatory cytokine with immunosuppressive activity; increased IL-6 production is common among individuals with chronic stress and depression.)

3) Subjects who participated in a three-month mindfulness meditation program demonstrated increased activity in immune cell telomerase, an enzyme responsible for preventing immune cell death. Suppressed telomerase activity is related to increased stress perception. Increased telomerase activity is associated with decreased LDL cholesterol and epinephrine.

4) A “perception” approach to mindfulness and the immune system

Another proposed mechanism, in contrast to the stress-reduction paradigm, is a “perception” approach to meditation’s effect on the immune system, whereby one sensory modality shifts to accommodate another sensory modality. This perception approach is demonstrated by the classic “prism experiment”. If you are holding an object in your palm, you are receiving information from both visual and proprioceptive modalities. If a prism is placed in your line of vision, however, there is a perceptual discrepancy between the information from the two modalities. To overcome this discrepancy, one modality will attenuate to match the other. This “cross-modal adaptation” can also explain why mindfulness seems to positively influence the immune system. If one can visualize oneself as “healthy”, they can cause their immune system to attenuate to match the visualized information. However, there are two premises that must be accepted:  a) the immune system is a sensory modality, and that b) visualization involves the same neurobiological processes that vision does and thus also functions as a sensory modality. This mechanism lacks substantial empirical support, however, and could benefit from further study. This mechanism may not pertain to mindfulness, which is more about an open, non-intrusive introspection. However, it may support visualization-related practices, such as Tibetan g Tum-mo yoga, in which practitioners are able to regulate their body temperature [LINK]. 

References

Benson, H., Beary, J.F., Carol, M.P. (1974). The relaxation response. Psychiatry, 37, 37-46.

Davidson, R.J., Kabat-Zinn, J., Schumacher, J., Rosenkranz, M., Muller, D., Santorelli, S.F., Urbanowski, F., Harrington, A., Bonus, K., Sheridan, J.F. (2003). Alterations in brain and immune function produced by mindfulness meditation. Psychosomatic Medicine, 65, 564-570.

Jacobs, T.L., Epel, E.S., Lin, J., Blackburn, E.H., Wolkowitz, O.M., Bridwell, D.A., Zanesco, A.P., Aichele, S.R., Sahdra, B.K., MacLean, K.A., King, B.G., Shaver, P.R., Rosenberg, E.L., Ferrer, E., Wallace, B.A., Saron, C.D. (2010) Intensive meditation training, immune cell telomerase activity, and psychological mediators. Psychoneuroendocrinology.

Olivo, E.L. (2009). Protection through the lifespan: the psychoneuroimmunological impact of Indo-Tibetan meditative and yoga practices. Annals Of The New York Academy Of Sciences, 1172, 163-71.

Pace, T.W.W., Negi, L. T., Adame, D.D., Cole, S.P., Sivilli, T.I., Brown, T.D., Issa, M.J., Raison, C.L. (2008). Effect of compassion meditation on neuroendocrine, innate immune and behavioral responses to psychosocial stress. Psychoneuroendocrinology.

Tausk F., Elenkov, I., Moynihan, J. (2008). Psychoneuroimmunology. Dermatologic Therapy. 21(1), 22-31.