A Mechanistic Model for Yoga as a Preventive and Therapeutic Modality.

Yoga is an ancient Indian technique of healthy living. Numerous studies have corroborated yoga's beneficial effects, including a favorable influence on autonomic function and negative emotions. Extensive research in the last few decades has revealed the critical role that yoga can play in eradicating stress. This has laid to the foundation for a scientific understanding of pathophysiological changes attributed to stress, particularly at the molecular and genetic levels. This primarily has helped understand the epigenetic and genetic mechanism at play to induce and alleviate stress, particularly those related to emotional aberrations. As research has indicated, negative emotions are translated into vascular inflammation appropriately accentuated by a sympathetic predominant autonomic function. This cascade is bolstered by multiple factors, including activation of "stressor" genes and elaborating hormones, including steroids with sometimes nocuous consequences, particularly when chronic. Yoga has been categorically found to have inhibited each and every one of these baneful effects of stress. In fact, it also changes the neuronal circuits that potentiate such a plethora of pathological changes. This, in turn, has accentuated yoga's relevance as a powerful preventive intervention in noncommunicable diseases (NCD). NCDs, including heart disease, stroke, and rheumatological disorders, are essentially inflammatory diseases that perpetuate inflammation in different beds like vascular or joint spaces. The precise mechanism by which yoga induces such beneficial changes is yet to be delineated. However, a cornucopia of pointers indicates that neural, endocrine, immunological, cellular, genetic, and epigenetic mechanisms are at play. This article attempts to cobble together newfangled research to delineate a medical model for this 5000-year-old practice from India. This is imperative, as a mechanistic model of this ancient-but-complex system would enable a more comprehensive understanding of its mechanism and reveal its yet-undiscovered positive health effects.