Dr. Lucia Aronica, PhD, is a Lecturer at Stanford University and Genomics R&D Lead at Metagenics Inc., specializing in nutrigenomics. She collaborates with clinicians to advance personalized lifestyle medicine, drawing from over 15 years of research at top institutions including Stanford, Oxford, and Vienna, and shares her opinion on whether epigenetic clocks show people's true age.
Everyone wants to live longer, but nobody wants to get old. Aging is a natural process that affects us all. We witness its effects on our bodies and minds as the years pass by. Yet, have you ever pondered why some individuals seem to age more gracefully than others? In the last decade, scientists have delved into this question, uncovering novel tools to determine our biological age, distinct from our chronological age.
Understanding biological age
Chronological age represents the number of years since birth, while biological age reflects the physiological age of cells and tissues, influenced by genetics, environment, and lifestyle factors.
"Conceptualize biological age as a multifaceted kaleidoscope, where each cell type and its biological processes form a distinct shard."
Similar to the array of colors and patterns in a kaleidoscope, our cells age at varying rates and in diverse ways. For instance, consider Alzheimer's patients, whose brains seem to undergo accelerated aging, as if the brain shard within their kaleidoscope spins faster. Conversely, sun-tan enthusiasts experience faster aging in the skin shard of their kaleidoscope.
Estimating biological age
Biological age is a complex construct, and no single test can fully capture its intricacy and variations across different cell types, organs, and individuals. Three primary categories of biological age tests exist: molecular, digital, and clinical/functional.
Molecular tests measure specific markers associated with aging, such as epigenetic changes, inflammatory markers, and telomere length.
Digital clocks utilize data from wearable devices and health records to track changes in skin photoaging, activity levels, sleep patterns, heart rate variability, and more.
Clinical or functional tests assess physical and cognitive performance through methods like blood panels, cognitive tests, grip strength evaluations, and VO2max tests.
Epigenetic clocks serve as a molecular test for estimating biological age by analyzing specific epigenetic modifications. These modifications regulate gene expression and can be influenced by factors like genetics, lifestyle choices, and aging itself.
"Epigenetic clocks capture various age-related changes in DNA methylation (DNAm), one of many epigenetic modifications, to estimate both chronological and biological age."
Different types of epigenetic clocks focus on distinct DNAm patterns and their correlations with age-related characteristics, such as alterations in blood lipids, inflammatory markers, and physical performance metrics.
Epigenetic age and lifestyle
While genetics do influence the aging process, lifestyle factors such as diet, exercise, and stress reduction play a more significant role.
"These factors have been shown to positively impact our epigenetic age, highlighting the importance of our everyday choices in shaping our epigenetic landscape and overall well-being. "
This transformative health paradigm is what I call "epi-wellness," harnessing the potential of lifestyle adjustments to promote positive epigenetic changes, prevent detrimental ones, and actively contribute to healthy aging.
Are epigenetic clocks ready for clinical use?
Epigenetic clocks display promise in estimating biological age, but further research is necessary to assess their clinical utility due to the complexity of aging and the requirement for personalized and comprehensive biomarkers. Longitudinal studies involving diverse groups of individuals, different interventions, and different epigenetic clocks are crucial to validate their use in combination with other clinical and digital biomarkers of aging, and comprehend the mechanisms underlying their relationship with aging and age-related diseases.
Aging and organ-specific variation
Aging is a complex interplay of multiple factors, and no single measurement can capture its entirety.
"Notably, individuals can exhibit different "ageotypes," indicating that their organs age at different rates. "
For instance, one person may have an older biological age for their liver, while another may have an older age for their kidneys. In cases where diseases affect a specific organ, combining multiple biomarkers specific to that organ may provide a more accurate estimation of biological age and prediction of disease risk.
While we await further advancements in the field of epigenetic clocks, we can take steps to improve our epigenetic age by embracing "epi-wellness" in our daily lives. Educating ourselves about the power of lifestyle choices in promoting healthy aging through epigenetic changes is crucial.
"By understanding how our everyday decisions regarding diet, exercise, and stress management can positively impact our epigenetic landscape, we gain the motivation to make meaningful behavior changes."
As the philosopher Friedrich Nietzsche once said, "One who has a 'why' to live for can endure almost any 'how'." This sentiment resonates deeply when it comes to aging and the pursuit of healthy longevity. By finding purpose in improving our biological age and understanding the connection between our lifestyle choices and epigenetic well-being, we can navigate the aging process with resilience and determination.
In conclusion, the development of epigenetic clocks is only one of the many windows into our "true" age — our biological age. It offers insights into the dynamic nature of aging and the impact of genetics, environment, and lifestyle factors on our overall well-being. While further research is needed to fully harness the potential of epigenetic clocks and refine their clinical utility, we can start making positive changes in our lives today by prioritizing epi-wellness. By doing so, we can strive to age gracefully and lead fulfilling lives, defying the limitations imposed by mere chronological age.
- Aging. Potential reversal of epigenetic age using a diet and lifestyle intervention: a pilot randomized clinical trial.
- The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences. Effects of Vitamin D3 Supplementation on Epigenetic Aging in Overweight and Obese African Americans With Suboptimal Vitamin D Status: A Randomized Clinical Trial.
- GeroScience. One-year Mediterranean diet promotes epigenetic rejuvenation with country- and sex-specific effects: a pilot study from the NU-AGE project.
- Neuroscience Insights. DNA Methylation Clocks and Their Predictive Capacity for Aging Phenotypes and Healthspan.
- HHS Public Access. Measuring biological age using omics data.