Molecular markers, mechanisms and metrics of biological aging: a scoping review.

Biological aging is a rapidly growing area of research, which entails characterizing the rate of aging independent of an individual's chronological age. In this scoping review, we analyze the results of biological aging research in 435 papers published in a 12 year window spanning 2011 through June 2023, 309 of which focus on non-methylation-based biomarkers, revealing changing patterns of molecular markers of biological aging use over time as well as the development of novel metrics of biological aging. We further identify consistent and discordant research findings, as well as areas of potential future research focusing on questions of measurement with biomarker-based assessment and other variables relevant to the study of biological age.