Novel epigenetic biomarker of health - biological age

Biological age is a measure of lifestyle, habits, and innate factors that cause us to age. How an individual’s biological age should be measured and what factors should be included and weighted to calculate a biological age continues to be of great interest to researchers. Today, it is understood that individuals experience different rates of aging resulting from progressive deterioration, occurring simultaneously at the molecular, cellular, tissue, organ, and functional levels. This is manifest in our daily lives as people of the same age develop age-related diseases and, ultimately, die at different ages.

While many approaches to quantifying biological age have been proposed, no approach has received more attention than the “epigenetic clock.” Beginning in 2011, researchers published a series of papers detailing the discovery of an epigenetic clock that uniquely tracked chronological aging. These articles highlighted the fact that “from the moment of conception, we begin to age,” causing our cellular structures, gene regulation, and DNA sequence to decay. The discovery of the epigenetic clock showed that epigenetics could be used to measure the cumulative effect of aging on our biological system, and with significant implications for developmental biology, cancer, and aging research.

Since the discovery of the epigenetic clock, researchers have developed a number of different ‘clocks,’ each with their own unique attributes, but most shown to be associated with risk of mortality and age-related diseases, even after accounting for chronological age. These clocks accounted for chronological age by taking the differential between epigenetic age and chronological age - with the difference referred to as epigenetic age ‘acceleration’ or ‘deceleration.’ The mortality associations have held true across racial/ethnic groups, body mass categories, sexes, smoking classes, physical activity status, cancer status, coronary artery disease status, or diabetes status.

Scientists still do not fully understand the underlying mechanisms between biological changes and epigenetic age acceleration, but the linkage between epigenetic biomarkers of aging and mortality has been firmly established in numerous populations around the world.

These case studies seek to illustrate how epigenetic biomarkers could be used to enhance traditional measures of health, as well as provide new health markers to enhance mortality risk assessment. Though presented as separate cases, epigenetic age acceleration measures can be used in conjunction with other epigenetic tests for tobacco use, alcohol, or other disease/health states because they capture different aspects of health and, as such, have been shown to have independent contributions in their mortality associations. Moreover, epigenetic biomarkers could be used in conjunction or combination with traditional data sources.

More work remains before epigenetic biomarkers converge with mortality underwriting, but the results and insights gathered thus far offer promise and point to an era of modern underwriting and risk classification.