Relationship Between Meditation Depth and Waking Salivary Alpha-Amylase Secretion Among Long-Term MBSR Instructors

Salivary Alpha-Amylase as a Biomarker of Stress in Behavioral Medicine

In recent years, research in behavioral medicine has become increasingly focused on understanding how chronic and acute exposure to stress impacts health outcomes. During stress, the body’s physiological stress systems are activated. These systems closely interact with the immune system and are, thus, importantly implicated in the onset and maintenance of disease states. While much of the research in behavioral medicine that has investigated the effects of stress on disease has focused on the role of the hypothalamic-pituitary-adrenal axis and its downstream biomarker, cortisol, it is evident that the autonomic nervous system (ANS) also plays a crucial role in both the biological stress process and the manifestation and maintenance of stress-related symptoms. In recent years salivary alpha-amylase (sAA) has emerged as a valid and reliable marker of ANS activity in stress research and is therefore an important biomarker to consider in behavioral medicine. In this commentary, we will highlight research relevant for behavioral medicine that has utilized sAA measurements, both basally, and in response to stress, to examine ANS function in clinical populations. We will additionally summarize findings from studies that have examined the effects of various targeted interventions on changes in sAA levels. Through this, our aim is to present evidence that sAA can serve as a feasible biomarker of ANS (dys)function in health and disease. To this end, we will also highlight important methodological considerations for readers to keep in mind when including sAA assessments in their own studies. The overarching goal of this brief commentary is to highlight how a multidimensional approach toward physiological stress measurement can allow researchers to develop a better understanding of physical health and disease states.

Mindfulness Training for Improving Attention Regulation in University Students: Is It Effective? and Do Yoga and Homework Matter?

The present study examined the effects of mindfulness training on attention regulation in university students and whether the potential benefits of implementation are influenced by the yoga component of mindfulness-based interventions (MBIs) and/or by MBI homework practice. In a non-randomized trial with pre- and post-assessments, n = 180 university students were allocated to either mindfulness training (experimental groups), awareness activities (active control group), or no training (passive control group). Mindfulness was taught through two MBIs, one including yoga and the other excluding yoga. Attention regulation was operationalized via behavioral indicators, namely sustained attention, cognitive flexibility, cognitive inhibition, and data-driven information processing. With the exception of speed in a cognitive flexibility task, the results indicated no systematic or differential advantage arising from mindfulness training, with or without yoga, regarding the aspects of attention regulation. There was no consistent influence of homework quantity or quality. The implications for mindfulness training in academic contexts are discussed.

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

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 (AUCI) and cortisol AUC above ground (above zero, AUCG); 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 AUCG 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.