DNA methylation-based biomarkers and the epigenetic clock of ageing

This paper reviewed research on DNA methylation, small chemical changes that help switch genes on or off. It looked at studies of people of different ages, using samples such as blood and other tissues. Researchers combine these changes into an “epigenetic clock,” an estimate of biological age rather than the number of years someone has lived. These clocks often match chronological age and are linked with health and lifespan, but they do not prove that the clock causes ageing or predict one person’s future accurately.

What this means for you: This is a research tool, not a proven reason to buy an ageing test, supplement, or treatment. It may help scientists study ageing, but it does not yet tell individuals what action will extend their lives.