UC Davis

In this dissertation I consider the role of psychosocial stress in mental and physical health, and investigate the role of a month-long Buddhist meditation retreat in altering the pathways between our biochemical makeup and our experience of the world.

As living beings, we possess a tremendous capacity for adaptation, and yet we are deeply conditioned by circumstance and bound by certain truths. We inhabit bodies that deteriorate, yet the rate and form of this degradation varies wildly depending on our environments and prior experiences. Stress research considers how our experiences become embedded in our bodies in ways that contribute to illness and disease, while also considering the protective factors that mitigate these outcomes. Importantly, decades of research indicate that one of the most potent modulators of health and well-being are our relationships and psychosocial environment.

Buddhist philosophy and meditation practices offer another framework for understanding our interdependence with others, and for investigating the intricate system of causes and conditions that govern our existence. Much of our conditioning and adaptation happens outside of our awareness and conscious intent, and meditation practices are often designed to bring some of this content into conscious awareness, so that we can learn to differentiate between the aspects of our lives we have agency in and those that are inevitable.

In the Insight meditation tradition studied here, primary practices include directing one’s attention to the coming and going of bodily sensations and observing thoughts as transient phenomena without grasping or over-identification. These practices are taught in combination with practices designed to support the four immeasurables: loving-kindness, compassion, empathetic joy, and equanimity. Together, these practices aim to cultivate beneficial qualities of mind and positive aspirations for oneself and others that allow practitioners to live in greater harmony with the world around them.

In the studies presented here, I examine the psychobiological effects of engaging in a month-long, silent Insight meditation retreat. Meditation retreats are an increasingly popular form of meditation training characterized by intensive or concentrated periods of meditation practice. Retreats are commonly undertaken in residential retreat settings, where practitioners are removed from the distractions of daily life. During retreat, meditators often follow a rigorous schedule of formal practice under the guidance of experienced teachers, and with the social support of fellow practitioners. This structure is designed to support practitioners in using each moment and every activity as an opportunity for continued mindfulness practice. Meditators may also adopt the practice of noble silence, which entails temporarily refraining from speaking, communicating, or initiating eye contact with others to facilitate quietude. Together these conditions afford a unique opportunity for participants to observe their mental experience, to cultivate particular qualities of mind, and to experience meditative insights that may have synergistic effects on their overall well-being.

Although the burgeoning field of contemplative science indicates that meditation training can positively influence physical and mental health outcomes, the biological consequences of retreats are relatively understudied. In this project, we assessed blood-based biomarkers in experienced meditators attending a month-long Insight meditation retreat (n = 28), as compared to a control group (n = 34) of experienced practitioners, similarly comprised in age and gender, who were living their everyday lives. Blood samples were collected on day two of the retreat (Time 1) and again 3 weeks later (Time 2). Control participants were also assessed across a 3-week interval, during which they maintained their regular daily routines. In the studies presented here, I report the effects of the retreat intervention on measures of 1) cell aging, as indexed by measures of telomere biology; 2) neuroplasticity, as indexed by serum levels of brain derived neurotrophic factor; and 3) inflammation, as indexed by inflammatory gene expression and transcriptional regulation.

In chapter 1, I examine changes in telomere biology, including telomere length, telomerase activity levels, and telomere-related gene expression in white blood cells. Telomeres and the enzyme telomerase interact with a variety of molecular components to regulate cell-cycle signaling cascades, and are implicated in pathways linking psychological stress to disease. I report increased telomere length in our retreat group, compared to controls who showed no group level change. Moreover, these changes in telomere length were predicted by basal personality traits such that retreat participants highest in neuroticism and lowest in agreeableness demonstrated the greatest increases in telomere length. I also report changes observed in telomere-related genes that further suggest retreat-related improvements in telomere maintenance. Although I found no group-level changes in telomerase activity, retreat participants’ telomerase levels at Time 2 were inversely related to several indices of retreat engagement and prior meditation experience. Neuroticism also predicted variation in telomerase across retreat. These findings suggest that meditation training in a retreat setting may have positive effects on telomere regulation, which are moderated by individual differences in personality and meditation experience.

In chapter 2, I examine the effects of retreat on brain-derived neurotrophic factor (BDNF)—a modulatory neuroprotein implicated in learning, memory, and neuroplasticity. I then explore the possible role of neuroplasticity and BDNF on retreat-related changes in telomere length, considering the relationships between BDNF and telomere biology in the central nervous system and immune system. I found no effect of retreat on serum BDNF levels. I did, however, find a relationship between serum BDNF and moderate amounts of daily practice in control participants. I also found that BDNF at Time 1 predicted telomere lengthening during the retreat, suggesting that basal BDNF levels may play a role in retreat-related improvements observed in telomere biology.

In chapter 3, I examine the effects of retreat on the expression of 33 genes involved in inflammatory processes and cell aging. I report a pattern of gene expression in retreat participants indicative of a lower inflammatory burden—the most notable finding being consistent downregulation of the TNF-α-pathway, which was not observed in controls. These findings indicate that meditation retreat participation may influence some of the inflammatory mechanisms involved in the development of chronic diseases, and suggest that meditation retreats may have therapeutic potential, particularly for experienced practitioners.

Insights from fields as diverse as Buddhist philosophy, anthropology, biopsychology, neuroscience, and social genomics continue to demonstrate that how we perceive and experience the world shapes every aspect of our being, and, in turn, those aspects of our being affect how we influence the world around us. This study adds to these bodies of knowledge by exploring the biological changes that arise from retreats, which ideally contribute to personal growth and healing by offering opportunities for concentrated reflection, personal insight, and self-integration. As such, this dissertation grapples with how practitioners instantiate meditative learning and the health related implications of such practice.