What is the Origin of Horvath Clock?

The clock was developed in 2013 by Dr. Steve Horvath, a biostatistician and geneticist, based on a massive dataset of human tissue samples, representing a landmark achievement in geroscience. It is a data-driven construct, not an etymological term, with its significance lying in its ability to universally track age across virtually all human tissues and cell types. Its clinical adoption allows for the objective monitoring of longevity interventions.

What is the Mechanism of Horvath Clock?

The clock's mechanism is based on the phenomenon of DNA methylation, a primary epigenetic modification where a methyl group is added to the cytosine base, typically at CpG dinucleotides. The Horvath algorithm utilizes the methylation levels at 353 specific CpG sites, identified as being highly correlated with chronological age. These sites are thought to be key regulatory regions, and their methylation patterns serve as a precise molecular memory of biological time and cumulative cellular damage.

Horvath Clock

Meaning

The Horvath Clock is a specific, highly accurate epigenetic clock, a mathematical model that estimates an individual’s biological age by analyzing the methylation status of specific CpG sites across the human genome. This tool is clinically significant as a biomarker of aging, providing a quantitative measure of ‘epigenetic age’ that often deviates from chronological age, reflecting cumulative lifestyle and environmental damage. The clock’s output, known as age acceleration, is a powerful predictor of morbidity and all-cause mortality.