Relationship between Meditation and Waking Salivary Cortisol Secretion among Long-Term MBSR Instructors

Abstract

Background: A potential relationship between long-term meditation practice and stress reduction remains virtually unexplored. The purpose of this study was to characterize stress using salivary waking cortisol in a group of long-term meditators with training in the Mindfulness-Based Stress Reduction (MBSR) program. Materials and Methods: Four salivary cortisol samples were collected from meditators (n = 84) during the first hour of awakening. The waking cortisol rhythm was summarized using cortisol area under the curve (AUC) with respect to increased secretion above baseline (AUC_I) and cortisol AUC above ground (above zero, AUC_G); data on meditation duration and depth, perceived stress, and other covariates were collected via self-reported questionnaire. Results: Individuals in the highest quartile of years meditating (> 26 years) had statistically significantly elevated AUC_G values (p = 0.01) as compared to individuals in the lowest quartile of years meditating (≤10 years). This relationship was more pronounced among individuals waking at or before 6: 30 a.m. Conclusions: Overall, an increasing number of years of meditation practice was related to a higher waking cortisol response. These intriguing findings warrant additional exploration, as the stress response can be complex.