Environmental epigenetics: new horizons in redefining biological and health outcomes

Environmental factors can have profound influences on biological systems, particularly through their effects on epigenetic processes. Epigenetics provides a powerful framework for understanding the regulation of gene expression through the interplay between genetic predispositions, inherited epigenetic marks, and lifelong environmental influences. This review proposes that even subtle epigenetic changes may initiate cascading effects on gene regulation and biological systems, ultimately contributing to significant phenotypic outcomes, including the modification of developmental trajectories, disease susceptibility, and adaptive responses. The reversible and adaptable nature of epigenetic modifications enables organisms to respond dynamically to a wide range of stimuli throughout their lifespan. Conversely, maladaptive epigenetic regulation can be associated with pathologies, including cancer, diabetes, neurodegenerative disorders, and adverse mental health outcomes. Thus, epigenetic markers represent a promising target for risk prediction, prevention and therapeutic intervention. In this narrative review, we discuss the wide-ranging implications of epigenetic theories underlying gene-environment interactions. Furthermore, we examine the evolving expectations of the scientific community and the public regarding epigenetic theories, which may shape future research directions and drive therapeutic innovation in health and disease. Epigenetic concepts are poised to bridge the gap between genetic predispositions and environmental influences, offering novel insights into complex biological processes and their outcomes.