Hormesis and epigenetics: is there a link?

Epigenetic regulation of gene expression is a key molecular mechanism linking environmental factors with the genome with consequences for health status throughout the life course. According to the modern view, epigenetic changes are far more likely than genetic changes to be directed, and many of these changes are manifestly adaptive. Recent experimental studies clearly indicate that environmental fluctuations can induce specific and predictable epigenetic-related molecular changes, and support the possibility of adaptive epigenetic phenomenon. The epigenetic adaptation processes implying alterations of gene expression to buffer the organism against environmental changes support adaptability to the expected life-course conditions. It appears likely that adaptive epigenetic rearrangements can occur not only during early developmental stages but also through the adulthood, and they can cause hormesis, a phenomenon in which adaptive responses to low doses of otherwise harmful conditions improve the functional ability of cells and organisms. In this review, several lines of evidence are presented that epigenetic mechanisms can be involved in hormesis-like responses.