Imagine having a watch that can measure the age of almost every cell in your body with astonishing accuracy. What sounds like an invention from the future is already possible today. We have a mathematician to thank for this, the German-American researcher Steve HorvathWith the Horvath clock named after him, we can biological age of cells down to the month.
In this article, we'll dive deep into the world of the Horvath Clock and explain what makes this epigenetic clock so unique, how it works, and what implications it has for aging research. You'll also learn more about its discoverer, Steve Horvath.
Who is Steve Horvath?
Steve Horvath is a German-American biostatistician, geneticist and leading researcher in the field of aging research. Born in Germany and later immigrating to the United States, Horvath currently teaches as a professor of human genetics and biostatistics at the University of California, Los Angeles (UCLA).
Already in his early youth, Steve Horvath was fascinated by the concept of aging. The question of how to live longer and healthily occupied the young Steve Horvath very much. Together with his twin brother and a mutual friend, the three vowed to strive to answer the question of healthy aging in their professional lives. The model was the ancient Babylonian epic of Gilgamesh, who dives into the depths of the ocean in search of eternal youth to find the herb of immortality.
Steve Horvath did not discover "the herb of immortality," but he developed a mathematical model that enabled him to model aging itself. And this, he hopes, will lay the foundation for reversing aging.
What is the Horvath Clock?
The Horvath Clock is a epigenetic test, which biological age of an individual. This method is based on the analysis of DNA methylation patterns that are systematically changed over time. DNA methylation is an epigenetic mechanism in which methyl groups are added to DNA molecules, thus influencing gene expression without changing the DNA sequence.
Steve Horvath discovered that certain regions of DNA - so-called CpG sites - exhibit systematic changes in their methylation patterns over the course of life. By studying and mapping these specific changes, Horvath was able to create an "epigenetic clock" that very accurately predicts the biological age of an organism based on methylation at 353 specific CpG sites.
Did you know?
Steve Horvath's scientific work was initially rejected by many editors. The results and the accuracy of the Horvath clock were "too good to be true." After several rejections, Steve Horvath first treated himself to three bottles of beer and then wrote an angry letter to the editor. With success, his article was subsequently published in the renowned "Genome Biology".
Measuring Biological Age: The Concept of "Biological Age"
Traditionally, a person's age is defined by chronological age, i.e. the number of years since birth. Biological age, on the other hand, refers to the physiological state of the body and can differ greatly from chronological age. A younger biological age may indicate better health and a longer life, while an older biological age may indicate an increased risk of age-related diseases and premature mortality.
The Horvath Clock provides a method to assess this biological age by analyzing the pattern of DNA methylation in blood samples, saliva, or other cell types. This methodology has proven to be extremely accurate and provides valuable insights into the aging process at the cellular level.
Did you know?
Biological age is incredibly accurate, even by scientific standards. Biomarkers have a correlation of roughly 0.6 to 0.7. For comparison, telomere length, for which Elisabeth Blackburn won the Nobel Prize, has a correlation with age of 0.5. The Horvath Clock had a correlation of an impressive 0.96!
Or to put it another way, the Horvath watch is a very accurate measuring instrument.
Epigenetics and the Horvath Clock
epigenetics is a field of research that deals with changes in gene expression that occur independently of changes in the DNA sequence. Epigenetic mechanisms, such as DNA methylation, play a key role in the regulation of many biological processes and are crucial for an organism's ability to adapt to environmental factors.
The Horvath Clock uses these epigenetic principles to estimate biological age. By systematically recording the methylation states of 353 specific CpG sites, the clock can make precise predictions about the biological age of the tissue testedThese CpG sites were identified based on their strong correlation with chronological age in different tissue types, making the Horvath Clock a universal tool for various biological samples.
Methylations, epigenetics – is there an easier way?
Admittedly, many of the concepts mentioned are highly scientific. So that you can gain a better understanding of them and avoid having to read dozens of studies, we will try to explain the connections more easily using an example.
Imagine your DNA like a giant orchestra. Around each instrument are volume control placed that can be turned up or down. These volume controls symbolize epigenetics. Through various biochemical processes (such as the methylation mentioned above), our body can turn certain areas of the DNA up or down. Translated, this means that epigenetics determines which parts of the DNA are read and which are not.
Steve Horvath has now discovered that there are very specific patterns in the setting of these volume controls that accompany aging. And that is exactly what the Horvath clock measures. Horvath can therefore say quite precisely how “old” a cell is on a biochemical level.
Applications of the Horvath Clock
The Horvath Clock has wide-ranging applications, both in basic research and in clinical and medical contexts:
- Research on aging and longevity: The Horvath Clock allows scientists to study the influence of various factors on the aging process, including environmental factors, genetic predispositions and lifestyle changes. Research results can be used to develop strategies to promote health and prolong life.
- early detection of diseases: Biological age, measured with the Horvath Clock, can provide early indicators of age-related diseases such as cardiovascular diseases, cancer or neurodegenerative diseases. This enables early interventions and targeted preventive measures.
- monitoring of therapies: The Horvath Clock can be used to evaluate the success of anti-aging therapies or other medical interventions. Changes in biological age could indicate how effective a particular treatment is.
- Clinical trials: In clinical trials, the Horvath Clock can be used to evaluate the effects of new drugs or interventions on the aging process and thus determine their potential benefits or risks before they are launched on the market.
Horvath Uhr, EpiAge, DunedinPACE or TruAge – what is behind the new generations?
In addition to the Horvath clock, there are now a whole range of epigenetic teststhat can measure biological age. The concept is still largely the same, meaning that the newer tests also measure methylation sites on the DNA. The difference lies in the points that are measured (the EpiAge test, for example, uses “only” 13 points, which are all the more accurate). and secondly, the algorithm behind it is different. Tests such as the DunedinPACE test indicate the speed at which you age. If you are wondering where the name comes from, Dunedin is a city in New Zealand where the data for the test was collected. The DunedinPace and the TruAge test are also the basis of the Rejunvenation Olympics. A competition that was created by the American Bryan Johnson to determine who ages the slowest. This has, in addition to Bryan Johnson also attracted other biohackers, such as the 61-year-old Dave Pascoe, who has a biological age of just 38 years. Pretty impressive.
What influences the Horvath Clock?
The Horvath Clock and its successors have been tested for more than 10 years, and some interesting facts have emerged. The most surprising thing is that biological age can be influenced. The biohacker scene in particular has impressively proven that one can turn back one’s biological age.
But what about the other direction and are there cases where biological age only changes for a short period of time?
Older biological age – a risk marker?
There is still no consensus in the scientific community on how to interpret the results of the Horvath clock. Are they “just” a mathematical model or do they really reflect aging processes in our bodies? To clarify this question a little better, the researchers evaluated huge amounts of data. Connection quite clearly. People with a large discrepancy between chronological age and biological age have an increased risk of developing certain diseases, e.g. of the cardiovascular system.
Surgery, stress and infections as short-term influencing factors
Imagine you have taken a test to determine your biological age and you are older than expected. This will probably be a shock for many people and it also raises the question of whether you are now at an increased risk of certain diseases.This example makes it clear that measuring biological age does not always show the complete picture, as it can also be influenced by short-term events.
To demonstrate this effect, the researchers in this study looked at various scenarios in more detail:
Operations make us grow older - at least in the short term
Operations mean a lot of stress for our bodies. So it was reasonable to assume that this would affect our biological age. And indeed, shortly after an operation, our biological age shot up. This is probably a sign from our body that it is using up a lot of resources for repair. The good news is that just a few days after an operation, our biological age returned to normal.
Infections affect the Horvath clock
Infections such as COVID-19 also have a demonstrable effect on our biological age.They make us appear older than we actually are for a short time. For this reason, it is not recommended to do an epigenetic age test if you are feeling ill or if you have just recovered from an infection. This could distort the results.
And the researchers discovered one last, exciting point in their work. Stress also seems to not only make us age externally, but our biological age is also influenced internally by stress.
Case Studies: Practical Applications of the Horvath Clock
In recent years, the Horvath clock has become a permanent instrument in science. We now know that biological age can give us very sound information about our health. Proper nutrition, exercise and stress reduction can reduce biological age.
The Horvath watch and its successors can also be used to test potential molecules in longevity research. For example, in this study the molecule alpha-ketoglutarate tested for 7 months. During this period, the subjects took a mix of alpha-ketoglutarate and vitamins daily. The impressive end result: the participants were able to reduce their biological age by an average of 8 years!
Challenges and Future Research
Despite the impressive successes of the Horvath Clock, challenges and open questions remain. One of the biggest challenges is to better understand the mechanisms underlying the epigenetic changes measured by the Horvath Clock. A deeper understanding could help develop targeted interventions that could slow or reverse the aging process.
It is also important to conduct further validation studies to verify the accuracy of the Horvath Clock in different populations and under different environmental conditions. Such studies could help to confirm the general applicability of the clock and identify possible limitations.
Conclusion: The Revolution in Aging Research
The Horvath Clock and Steve Horvath's research have revolutionized our understanding of aging. By precisely measuring biological age using DNA methylation markers, the Horvath Clock provides valuable insights that go far beyond what is possible through traditional measures of chronological age.These findings have the potential to improve the prevention and treatment of age-related diseases and to develop strategies to promote healthy ageing and extended lifespan.
Steve Horvath's work impressively demonstrates how interdisciplinary research and innovative thinking can lead to groundbreaking discoveries. The Horvath Clock is a prime example of how epigenetic research can find practical applications in everyday life and offer the prospect of a better quality of life for all people.
