Dr. Steve Horvath on epigenetic aging to predict healthspan: the DNA PhenoAge and GrimAge clocks

Horvath Clock

Steve Horvath, a professor at UCLA, developed the Horvath aging clock, a pan-tissue epigenetic clock that accurately measures chronological age across various cells, tissues, and organs. This clock can estimate age from DNA samples taken from blood, neurons, saliva, or urine, making it a versatile tool in aging research 1. Rhonda Patrick highlights that Horvath's work has been pivotal in biology, leading to the development of even more precise aging clocks 2.

The Horvath aging clock is what I sometimes call the so-called pan-tissue epigenetic clock. And so it is the most accurate molecular measure of age. It applies to all cells in the bodies, certainly all cells that have DNA, all tissues, all organs.

--- Steve Horvath

Horvath's clock measures age from prenatal stages to supercentenarians, providing a deep insight into the aging process across the lifespan 1.

   

PhenoAge vs GrimAge

Horvath's work extends to developing epigenetic clocks like DNA PhenoAge and GrimAge, which predict healthspan and lifespan. These clocks are designed to measure time to death or onset of major diseases, making them valuable in clinical trials for anti-aging interventions 3. GrimAge, for instance, can predict the onset of coronary heart disease and cancer, although its clinical utility is still under evaluation 3.

We have some epigenetic clocks whose purpose is really to measure chronologic age period. But then we have other epigenetic clocks that are really defined to be lifespan predictors.

--- Steve Horvath

The GrimAge clock uses over 1,000 genomic locations, reflecting the complexity and global nature of methylation changes with age 4.

   

Chrono vs Bio Age

The distinction between chronological and biological age is crucial in Horvath's research. While chronological age is a simple measure of time, biological age reflects the actual physiological state of an individual, often revealing discrepancies through DNA methylation patterns 5. Horvath's epigenetic clocks can identify these differences, showing that some individuals age faster or slower biologically than their chronological age would suggest 5.

The epigenetic clock may say, well, this person is actually 55 or 45. And so there's a small error. And this error is actually biologically meaningful.

--- Steve Horvath

Research has shown that interventions like growth hormone receptor knockouts in mice can slow biological aging, validating the accuracy of these clocks in measuring biological age 6.