Grow Younger, Live Longer

Biological age has gained traction as a way to scientifically assess the degree of aging beyond just years lived. However, there’s a burgeoning interest in a new metric dubbed “functional age” that could be a more accurate yardstick for monitoring consumer longevity interventions.
With increasing consumer interest in longevity, biological age calculations are not only used in scientific research but also as tools for individuals keen on understanding their aging process. While various metrics like epigenetic patterns, microbiome data, and blood-based biomarkers contribute to the calculation of biological age, there’s growing acknowledgment that they may not mirror real-life improvements in health.
That’s why tracking healthspan becomes essential in understanding the true effectiveness of longevity interventions and optimizing overall well-being. By regularly monitoring healthspan, individuals can assess the tangible impact of their lifestyle choices and make informed decisions to improve their quality of life.
Dr. Julia Cooney, CEO of Zest, a consumer longevity startup, has developed an AI-powered platform that introduces the concept of functional age.1 Functional Age. How Old Are You… Source Zest’s functional age calculation, with its integration of digital, functional, and blood biomarkers, provides a comprehensive approach to tracking healthspan progress.
This metric measures changes in physical and cognitive capabilities and well-being, making it a potentially more meaningful gauge for tracking progress in longevity regimens. Cooney argues that while accurate at correlating to chronological age, biological age measurements do not adequately capture functional abilities or reflect how young a person feels.

Utilizing tools like DNA methylation clocks could discourage and demotivate people, as the modifications in one’s lifestyle could take an extended period, potentially up to two years, to reflect in their biological age scores. Contrarily, functional age calculations appear more beneficial, providing immediate feedback that better aligns with an individual’s sensed health improvements and personal experiences.
Functional age refers to measuring an individual’s health, fitness, and performance capabilities that may not align with their chronological age. It considers a broad spectrum of health indicators, ranging from physical to cognitive capabilities.
Among these various markers, established blood panel markers offer insights into the biochemical processes in our bodies.
One standout among the digital biomarkers is VO2 max, a measure of cardiovascular fitness and endurance. Our previous article on VO2 max delved into how this measurement is considered the gold standard for evaluating cardiovascular fitness and how it correlates with healthspan and lifespan.
Along with VO2 max, sleep quality is another key digital biomarker. Adequate quality sleep is integral to good health, playing a vital role in everything from memory consolidation to metabolic regulation.
On the functional biomarkers front, tools such as cognitive testing and grip strength provide tangible measures of mental and physical capacity. Cognitive tests assess brain functions like memory, attention, and language skills, while grip strength is a simple yet effective proxy for overall muscle strength and function.
In creating an estimate of functional age, Zestβs AI algorithm ingeniously collates all these measurements. It then contrasts them against reference values matched to your chronological age. The result is a functional age estimation that is not only reflective of your physical and cognitive performance but also resonates with your day-to-day life. In essence, it’s an age metric that evolves in real-time, in harmony with your lifestyle interventions and health improvements.
Functional Age, as implemented by Zest, is currently in its beta testing phase. The company is actively seeking early adopters who are interested in pioneering this new approach to health and longevity measurement. Individuals who participate in this early testing phase have the opportunity to shape the tool’s development and be at the forefront of this novel aspect of personal wellness.
In conclusion, while the concept of functional age is still in its early stages, it holds immense promise for revolutionizing personal wellness and longevity. Being based on real-time data, it can provide individuals with immediate feedback, keeping them motivated as they witness rapid improvements through lifestyle interventions. Furthermore, the biomarkers utilized by Zest in their functional age calculation have a robust scientific background, making them some of the most reliable indicators for assessing healthspan and lifespan. As this field continues to evolve, functional age has the potential to become an indispensable tool in optimizing health and enhancing overall well-being.
- 1Functional Age. How Old Are You… Source