Imagine having a clock 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 to the exact month.
In this article, we delve 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).
Even in his early youth, Steve Horvath was fascinated by the concept of aging. The question of how to live longer and healthier was of particular interest to the young Steve Horvath. 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. Their inspiration was the ancient Babylonian epic of Gilgameshwho, in his search for eternal youth, dives into the depths of the ocean to find the herb of immortality.
Steve Horvath didn't discover "the herb of immortality," but he developed a mathematical model with which he could model aging itself. And with this, he hoped, the foundation was laid 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 altered 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 accurate 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 journal "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 significantly 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 for assessing this biological age by analyzing the pattern of DNA methylation in blood samples, saliva, or other cell types. This methodology has proven extremely precise and provides valuable insights into the aging process at the cellular level.
Did you know?
Biological age is incredibly precise, even by scientific standards. Biomarkers have a correlation of approximately 0.6 to 0.7. By comparison, telomere length, for which Elisabeth Blackburn received 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 precise measuring instrument.
Epigenetics and the Horvath Clock
Epigenetics is a field of research that studies 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 tested tissueThese CpG sites were identified based on their strong correlation with chronological age in various 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. To help you gain a better understanding of them and avoid having to read dozens of studies, we'll 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 (like the aforementioned methylation), our body can turn certain sections 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's exactly what the Horvath clock measures. This allows Horvath to 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 findings can be used to develop strategies for health promotion and life extension.
- Early detection of diseases: Biological age, measured with the Horvath Clock, can provide early indicators of age-related diseases such as cardiovascular disease, cancer, or neurodegenerative diseases. This enables early interventions and targeted preventive measures.
- Monitoring of therapiesThe 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 market launch.
Horvath Uhr, Molecular Profile, 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 the newer tests also measure methylation sites on DNA. Tests such as the DunedinPACE test indicate the rate at which you age. In case you're 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 tests are also the basis of the Rejuvenation Olympics. A competition, which was founded 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. 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. Perhaps the most surprising thing is that biological age can be influenced. The biohacker scene in particular has impressively demonstrated that it is possible to reverse one’s biological age.
But what about the other direction and are there cases where biological age only changes for a short time?
Older biological age – a risk marker?
There's still no consensus in the scientific community on how to interpret the Horvath Clock results. Are they "just" a mathematical model, or do they truly reflect aging processes in our bodies? To shed some light on this question, researchers analyzed vast amounts of data. A connection emerged quite clearly. People with a high 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've taken a test to determine your biological age and you're older than expected. This is likely a shock for many, and it also raises the question of whether you're now at increased risk for certain diseases. This example clearly shows that measuring biological age doesn't always paint the complete picture. It can also be influenced by short-term events.
To demonstrate this effect, the researchers took a closer look at various scenarios in a study:
Operations make us age - at least in the short term
Operations mean a lot stress for our bodies. It was therefore reasonable to assume that this would affect our biological age. And indeed, it did. Shortly after surgery, our biological age shot up. This is probably a sign from our body that it is expending a lot of resources on repair. The good news: Just a few days after the procedure, 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 take an epigenetic age test if you feel ill or have recently recovered from an infection. This could distort the results.
And the researchers discovered one last, exciting point in their work. Stress also seems to make us age not only externally, but also internally, our biological age is influenced by stress.
Case studies: Practical applications of the Horvath Clock
In recent years, the Horvath Clock has established itself as a definitive tool in science. We now know that biological age can provide us with very solid 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 Alphaketoglutarate for 7 months. During this period, the subjects took a daily mix of alpha-ketoglutarate and vitamins. 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 unanswered questions remain. One of the most significant 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.
Furthermore, further validation studies are important to verify the accuracy of the Horvath Clock in different populations and under different environmental conditions. Such studies could help confirm the general applicability of the clock and identify potential 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 far beyond those available through conventional measures of chronological age. These findings have the potential to improve the prevention and treatment of age-related diseases and develop strategies to promote healthy aging 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 everyone the prospect of a better quality of life.
