Epigenetic Clock
A biological age measurement tool that uses patterns of DNA methylation, chemical modifications to DNA that change predictably with age, to estimate a person's biological age.
An epigenetic clock is an algorithm that estimates biological age from patterns of DNA methylation across the genome. DNA methylation refers to the addition of methyl groups to specific sites on the DNA molecule. These methylation patterns change predictably as people age, and the pattern at any given time strongly correlates with both chronological age and future healthspan outcomes.
The first widely validated epigenetic clock, Horvath's Clock (2013), could estimate age from any tissue in the body with surprising accuracy. Subsequent clocks have been refined to measure not just current biological age but the pace of aging:
- GrimAge: trained on mortality endpoints; predicts life expectancy and time to first disease better than Horvath's Clock - DunedinPACE: measures the pace of aging (how fast a person is aging relative to their peers) rather than current biological age - PhenoAge: combines blood chemistry with epigenetic data to estimate phenotypic age
Epigenetic clocks are used in longevity research, clinical longevity medicine, and by some consumers through direct-to-consumer testing services.
A researcher might measure a participant's DunedinPACE before and after a 12-month exercise and nutrition intervention. If the pace of aging slows (a lower DunedinPACE score), it suggests the intervention is having a measurable effect on the rate of biological aging.