Species Extinction, Biodiversity, Human Health, and Inevitable Role of Lifestyle Medicine: A Narrative Review

Human health and the health of our planet are inextricably linked. The accelerating loss of global biodiversity represents one of the most profound health threats of the 21st century. With species extinction rates estimated to be 10-100 times higher than natural baselines, biodiversity decline is no longer solely an environmental concern. This narrative review synthesizes evidence suggesting that biodiversity decline is increasingly relevant as a determinant of human health and survival rather than solely an environmental concern. The six pillars of lifestyle medicine, offer a coherent framework for interventions that can simultaneously prevent and improve lifestyle related illness outcomes while improving planetary health by reducing environmental pressures that drive species extinction and biodegradation. The review examines evidence synthesized from peer-reviewed databases (MEDLINE, PubMed, CINAHL, Joanna Briggs, SCOPUS, ScienceDirect, and GreenFILE), primarily 2010-2025, organized across seven thematic domains: infectious disease ecology, ecosystem services, microbiome dynamics, lifestyle medicine interventions, One Health integration, behavioural change, and clinical/policy implications. The review argues that lifestyle medicine must evolve from individual-focused clinical practice to also explicitly address structural drivers of ecological degradation, including food systems, transport, and urban design, thereby operationalizing planetary health principles in clinical care.