For decades, longevity researchers have been trying to pinpoint the molecular changes that occur as we age. A major breakthrough came in 2013 when researchers like Steve Horvath and others developed the first “epigenetic clock.” These clocks use DNA methylation patterns to estimate the biological age of cells, tissues, and organs.
This groundbreaking tool has since been used to measure the rate of aging in hundreds of different species, from humans to fruit flies. As of October 2022, GrimAge, one of the most accurate epigenetic age tests, has been cited or used in thousands of studies. And they just might be a game-changer for anyone who wants evaluate the effectiveness of their own anti-aging pursuits from diet and exercise to advanced interventions, therapies and supplements.
In the field of longevity research, epigenetic clocks offer a powerful way to measure and better understand the aging process itself. Why? Because understanding how and why we age is the key to developing interventions that can slow down the aging process and improve our healthspan (the number of years we live in good health).
Here’s everything you need to know about epigenetic clocks and why they just might be a game-changer for longevity researchers and anyone pursuing living a longer, healthier life.
What is an Epigenetic Clock?
An epigenetic clock is a molecular timer that uses DNA methylation patterns to estimate a person’s biological age. In other words, it tells us how old our cells are, as opposed to our chronological age (the number of years we’ve been alive).
Epigenetic clocks are algorithms that use DNA methylation patterns to estimate the biological age of cells, tissues, and organs. Methylation is a process by which methyl groups are added to DNA molecules. These methyl groups attach themselves to certain genes and regulate their activity. This can change the activity of genes and affect how cells behave. It can also impact aging too.
DNA Methylation patterns change during development and also as we age—specifically, they become more irregular with age. So, by looking at someone’s DNA methylation patterns, researchers can get an idea of how fast their cells are aging.
By comparing our chronological age (number of birthdays) with biological age determined using epigenetic markers, epigenetic clocks can give us an estimate of how old our cells actually are biologically. This information is valuable because it can help us understand the health of our cells and identify potential health and aging problems early on.
How Do Epigenetic Clocks Work?
To create an epigenetic clock, researchers first need to collect DNA samples from people and animals of all ages and from different tissue types. They then look for specific methylation patterns in these samples. Once they’ve identified these patterns, they can create an algorithm that can estimate the biological age of future samples based on their methylation patterns.
There are many different epigenetic clocks currently in development, each with its own strengths and weaknesses. Some clocks are better at estimating the age of specific tissues, while others are better at predicting lifespan or healthspan. As more research is done on epigenetic clocks, we will continue to refine them and make them more accurate.
What’s more, because epigenetic changes can be influenced by lifestyle factors like diet and exercise, epigenetic clocks can also be used to measure the effects of these factors on cellular aging. This makes them a powerful tool for researchers who are working to develop interventions that can slow down the aging process.
The Benefits of Epigenetic Clocks
Because as we age, our cells age too. And this cellular aging is one of the main drivers of the physical and cognitive decline that comes with aging. So, by understanding how fast our cells are aging, we can get a better sense of our true health status and identify interventions that can slow down cellular aging and improve our healthspan.
Epigenetic clocks offer a number of advantages over traditional methods of measuring biological age.
- First, they’re more accurate. Traditional methods often rely on biomarkers like blood pressure or cholesterol levels, which can fluctuate over time and give us misleading information about our health. Epigenetic clocks, on the other hand, provide a more stable measure of cellular aging.
- Second, epigenetic clocks can be used to measure the aging of specific tissues or organs—not just the whole body. This is valuable information because it can help us identify which tissues or organs are aging faster than others and why this might be happening.
- Finally, epigenetic clocks could help us personalize anti-aging treatments and interventions. If we know how fast someone’s cells are aging, we can tailor treatments to slow down that aging process and improve their healthspan—the number of years they live without chronic disease or disability.
Beyond researchers and labs, longevity pursuers can use epigenetic clocks to determine how effective certain anti-aging therapies and inventions are on them. These early indicators from citizen scientists can also help orient new opportunities for longevity researchers too.
Limitations with Epigenetic Clocks?
No scientific tool is perfect, and epigenetic clocks are no exception.
One factor that limits epigenetic clocks and all measures of biological age is that we still don’t know what is aging. The Hallmarks of Aging remains a powerful mental model about key components of aging but scientists have yet to identify the so-called “aging mechanism,” though many clues have been found. Epigenetic clocks, in fact, offer some interesting evidence about the universality of aging effects across mammals and other species.
Additionally, in view of the fact that epigenetic clocks depend on patterns of DNA methylation, much work remains to determine the molecular and causal pathways that lead to these epigenetic marks over time.
- For example, how do our cells “tick” such that epigenetic clocks can measure our biological age?
- What are some mechanisms that create these markers? What drives DNA methylation patterns?
- For longevity pursuers and scientists too, can we intervene and change these mechanisms and reduce our epigenetic age?
Many questions remain but clinical trials like TRIIM-X from Intervene Immune and others are starting to offering cases where targeted advanced anti-aging strategies and therapies have actually reversed aspects epigenetic aging. In fact, it’s becoming possible to have an impact on your biological age with just lifestyle changes alone using exercise, diet and sleep.
Another limitation is that epigenetic changes are influenced by a variety of factors—not just aging. For example, exposure to environmental toxins or stress can cause changes in DNA methylation patterns. Smoking is a well-known cause of aging, so much so that GrimAge, a well-known epigenetic clock, creates a composite biomarker called pack years to indicate this component of aging. Impact of environmental aging on epigenetics and epigenetic clocks means that epigenetic clocks may not always give an accurate picture of someone’s true biological age and instead reflect a host of other factors in the environment. Put another way, while a biological age score represents a single summary of age, many factors in the past and present have happened in parallel to create our aging state and it is difficult to disentangle what played the most important role.
Conclusion:
Epigenetic clocks are a new way to measure biological age using DNA methylation patterns. Based on the number of citations and publications, the discovery of epigenetic clocks has been a game-changer for longevity research. Not only does it provide a way to measure the rate of aging, but it also opens up new avenues for enabling better research into interventions that could slow down the aging process.
At MyAgingests.com powered by Clock Foundation, we offer epigenetic clock-based biological age tests for humans and for companion animals. Our tests can help you determine the current state of your aging, give you recommendations on anti-aging strategies, and help you evaluate the impact of those interventions and changing over time. Originally developed for clinical trials and research, GrimAge is now available for individuals and longevity practitioners and considered the best predictor of all-cause mortality. Using a unique pan-mammalian epigenetic clock, our epigenetic age test for dogs, cats and companion
Epigenetic clocks offer many advantages over traditional methods—including their accuracy and the ability to measure the aging of specific tissues or organs—and could help us personalize anti-aging treatments in the future. As more research is done on epigenetic clocks, we will continue to refine them and make them more accurate so that we can unlock the secrets of aging and improve our healthspan collectively as a society.
The future of longevity research is bright, and epigenetic clocks will play a major role in helping us achieve our goal of living longer, healthier lives.
References:
- Lu, A. T., Quach, A., Wilson, J. G., Reiner, A. P., Aviv, A., Raj, K. et al. (2019). DNA methylation GrimAge strongly predicts lifespan and healthspan. Aging (Albany NY), 11(2), 303.
- McCrory, C., Fiorito, G., Hernandez, B., Polidoro, S., O’Halloran, A. M., Hever, A. et al. (2021). GrimAge outperforms other epigenetic clocks in the prediction of age-related clinical phenotypes and all-cause mortality. The Journals of Gerontology: Series A, 76(5), 741-749.
