A New Way to Measure Lifespan

Over a lifetime, the chemistry of DNA changes: in particular, the process of methylation is one of several epigenetic mechanisms that cells use to control gene expression.  Riccardo E Marioni, from the University of Edinburgh (United Kingdom), and colleagues completed a series of 4 independent studies that tracked the lives of almost 5,000 older people for up to 14 years. Each person's biological age was measured from a blood sample at the outset, and participants were followed up throughout the study. Researchers found that those subjects with greater DNA methylation were more likely to die sooner, even after adjusting for confounding factors. The study authors report that: “DNA methylation-derived measures of accelerated ageing are heritable traits that predict mortality independently of health status, lifestyle factors, and known genetic factors.”