Biological Clocks: How old are you really? Perhaps you can test for it now - real world case study.

Understanding Biological Age: Decoding the Future of Health and Longevity

As a longevity doctor, one of the most intriguing questions I encounter is: “How old am I, really?” While our chronological age – the number of candles on our birthday cake – ticks forward unchangingly, our biological age tells a different story. It reflects how well (or poorly) our body is aging, based on measurable markers of health, from cellular integrity to organ function.

This concept of biological age is a game-changer for anyone pursuing health and longevity. It moves us beyond averages and into the realm of personalization, allowing us to tailor interventions that slow, or even reverse, the aging process.

But how do we measure biological age? The answer lies in the rapidly advancing world of biological clocks. I will try to answer this question in this newsletter -- using data from one of my "longevity athletes".

What Are Biological Clocks?

Biological clocks are tools or methodologies designed to estimate biological age by analyzing key indicators of health, often at the molecular or cellular level. They give us a snapshot of how quickly we’re aging compared to our chronological age.

The difference between your biological age and chronological age provides valuable insights: - Younger biological age: Indicates better health and slower aging. - Older biological age: Suggests accelerated aging, which may correlate with a higher risk of chronic diseases and earlier mortality.

A Brief History of Biological Clocks

I won't be going into too much detail here as I have written about biological clocks a fair amount in the past. Check out this link as an example of one of my previous articles.

https://thelongevityhack.substack.com/p/biological-age-youre-only-as-old?r=1p1ex8&utm_campaign=post&utm_medium=web&triedRedirect=true

The idea of measuring biological age is not new, but advancements in molecular biology and big data have propelled it into mainstream health and longevity discussions. Early methods relied on telomere length, the protective caps at the ends of chromosomes that shorten as we age. Over time, more sophisticated tools have emerged, including epigenetic clocks, which measure age-related changes in DNA methylation, and functional clocks, which assess physiological markers like gait speed or lung capacity.

Today, a variety of clocks are available, each providing unique insights. To illustrate, I recently used multiple biological clocks to assess a patient, and the results showcase both the promise and complexity of this field.

If you would like to know more on the subject then you can check out the work by Prof Steve Howarth, Morgan Levine , Matt Kaeberlein and Prof. Andrea B. Maier .

Comparing Biological Clock Results

Here’s how different clocks evaluated the my patient’s biological age.

He is a "young" man of 29 years and 9 months (at the time of sampling) and of Indian decent. He is otherwise fit and healthy with no "major" health conditions.

How These Clocks Work

Each clock uses a unique methodology, reflecting different aspects of aging:

1. PhenoAge: Combines blood biomarkers (like glucose, albumin, and CRP) to estimate overall systemic aging.

2. Vascular Age Test: Assesses endothelial function and arterial stiffness to determine cardiovascular health.

3. Epigenetic Clocks (e.g., OmicmAge, DunedinPACE): Measure changes in DNA methylation patterns that correlate with aging and disease risk.

4. Telomere Length: Evaluates the length of telomeres as a marker of cellular aging.

5. Functional Biomarkers (e.g., Gait Speed, Grip Strength): Proxy measures of physical capability, reflecting neuromuscular and cardiorespiratory health.

6. Organ-Specific Ages: Evaluate specific systems (e.g., liver, kidney, heart) based on biochemical and physiological markers.

Results and Interpretation

The patient’s results highlight a fascinating divergence among clocks.

For example: - The vascular clock paints a picture of youthful cardiovascular health (21 years), supported by an excellent DunedinPACE score of 0.78.

However, the OmicmAge clock suggests accelerated aging, flagging potential risks for heart disease and diabetes.

Functional scores for VO2Max and grip strength are suboptimal, indicating room for improvement in aerobic fitness and muscle strength. Meanwhile, the immune system and liver age are slightly older, hinting at metabolic or inflammatory stress.

This variation arises because each clock measures a different dimension of aging. Biological aging isn’t a singular process; it’s a mosaic influenced by genetics, environment, lifestyle, and even stress.

I personally "like" using Phenoage as it's quick and easy (a simple blood test is all that's needed) and the results go into a calculator to arrive at the value. The downside is that is doesn't factor in some very important markers (like lipids as an example) but its fairly well accepted by the international community.

The Good, the Bad, and the Limitations

The Good: - Personalized Insights: Biological clocks allow for targeted interventions, from improving vascular health to optimizing mitochondrial function.

Monitoring Progress: Repeating these tests over time can reveal how interventions (e.g., dietary changes, exercise, or supplements) are working.

Early Detection: Some clocks identify risks (e.g., inflammation, cardiovascular disease) long before symptoms appear.

The Limitations: Variability Among Clocks: Different clocks provide different results, making interpretation complex - case in point from my patient's values above.

Population-Specific Norms: Most clocks are calibrated against Western populations, potentially skewing results for other ethnicities and that doesn't help me much here in India unfortunately.

Focus on Specific Systems: A clock like OmicmAge may overemphasise certain risks, while functional clocks may undervalue metabolic health. However I see this as valuable, as I can get deeper insights into systemic issues like inflammation, metabolic health or cardiovascular fitness.

How to Use These Results

For individuals pursuing health and longevity, biological clocks can serve as both a compass and a dashboard. It help set targeted goals, addressing weaknesses, like improving VO2Max through aerobic exercise or reducing inflammation with dietary changes.

It can help us track interventions, by using the clocks to measure the impact of biohacks, such as intermittent fasting, hyperbaric oxygen therapy, or red light therapy over time.

It creates a holistic view of a person and avoids fixating on any single result. The most meaningful changes come from addressing the entire biological picture.

In Conclusion

Biological clocks are more than a curiosity; they’re a window into the intricate and dynamic process of aging. By embracing these tools, we can take proactive steps to optimize our health and extend not just lifespan but healthspan – the years we live vibrantly and disease-free. As a longevity doctor, my goal is to decode this complexity for my patients, turning data into actionable insights and a longer, healthier life.

What will your biological clock reveal? The journey to discover it might just transform your future.

If you are based in India and would like to measure your biological age then drop me an email on marcus@humanedge. co

Our next cohort of "longevity athletes" kicks off in January so we can assess your suitability to join our four month long journey towards optimising your health and longevity.

PS- I would like to thank OpenAI 's ChatGPT LLM for its help in writing this article.