Tantra or Yoga. Clinical Studies, Part 1: Yoga

Several clinical studies demonstrate how exercises from Vedic traditions, such as Yoga, or Theravada and Mahayana Buddhism, as well as tantric practices, have a significant psychobiological impact. This study seeks to identify the neurophysiological correlates of practices referred to as tantric and non-tantric meditations through a qualitative systematic review of collected data. First, the results of non-tantric meditations were verified, followed by the collection of data on tantric meditations. These were then compared, and the findings are presented in three parts. In this first part, it was found that non-tantric meditations create a better relaxation response with increased parasympathetic activity and inhibition of the sympathetic system. This induces a hypometabolic state of deep rest, where the practitioner remains awake and their attention is in a state of "tonic alertness," accompanied by symptoms corresponding to this hypometabolic state—hypotonia, decreased oxygen consumption, reduced heart rate, and lower blood lactate concentration. Additionally, there are changes in normal endocrine function, increased phenylalanine concentration in advanced meditators, elevated plasma prolactin levels, a five-fold increase in plasma arginine vasopressin levels, and a chronic and acute decrease in thyroid-stimulating hormone. This research paves the way for longitudinal clinical studies to confirm the long-term beneficial effects of these practices and to establish mechanisms to counteract the undesirable side effects presented here.