Yoga as a complementary therapy for metabolic syndrome: A narrative review

Metabolic syndrome (MS) is associated with a sedentary and stressful lifestyle and affects underactive people disproportionately. Yoga is considered to be a low-impact mind-body stress-relieving exercise, and researchers are increasing their focus on the benefits of yoga for managing metabolic disorders. It is also important for physicians and health care professionals to understand the therapeutic efficacy of yoga intervention, in terms of its type, duration and frequency on various MS risk factors. The present review summarizes the current scientific understanding of the effects of yoga on MS risk factors such as glucose homeostasis markers, lipid profile, adipocytokines and cardiovascular risk factors, and discusses the possible mechanisms of action. MEDLINE, PubMed, Scopus and Cochrane Library were searched from their inception up to December 2019, using the keywords "metabolic syndrome," "diabetes," "cardiovascular diseases," "obesity" and "yoga." The literature summarized in this review have shown mixed effects of yoga on MS risk factors and do not provide robust evidence for its efficacy. More rigorous research and well-designed trials that have a higher standard of methodology and evaluate yoga's long-term impacts on MS are needed. Understanding yoga's biochemical and molecular mechanisms of action on various metabolic pathways is also needed.