We tend to count our lives in birthdays, yet biology keeps time in other ways. We can now measure how quickly cells and systems are changing, a rate that can differ widely between people of the same age. This biological age can be tracked over time, offering a practical way to understand whether daily habits and clinical strategies are moving health in the right direction.
In healthy longevity medicine, understanding biological age has become a cornerstone of personalised health optimisation. Unlike the fixed march of calendar years, your biological age is dynamic, measurable, and most importantly, modifiable through targeted interventions. A powerful application of biological age measurement lies in tracking your progress. Unlike static genetic testing, biological age should be re-measured over time to evaluate whether lifestyle modifications and nutraceutical medications are effective in lowering it.
Biological age can be measured at intervals to create a useful feedback loop. Chi Longevity clients can see whether targeted strategies are associated with a slower ageing rate, understand which adjustments make the most difference for them, and course-correct when the numbers flatten or drift.
Why biological age matters
Biological age reflects how well the body’s cells, tissues, and systems are working. It draws together the big drivers of health: eating patterns, sleep and activity, environment, genetics, medications, and other lifestyle habits, into one picture taken now.
The body runs on several clocks [1,2], each reflecting a different lens on health. Blood markers sketch organ and metabolic function; epigenetic patterns indicate how lifestyle and environment affect gene regulation and expression levels; inflammatory signals show the balance between protection and repair; and the gut microbiome reveals how our inner ecosystem supports energy, mood, and immunity. Consider two people the same age on paper: these clocks often explain why one recovers quickly after a busy week while the other feels persistently drained.
The clocks provide a baseline for today. Chi Longevity’s experts interpret the patterns, translate them into practical steps, and repeat testing at intervals to see whether the ageing rate and related risk signals are moving in a favourable direction. Every personal journey starts with your personal data. The aim is to use knowledge and science to optimise time, so that health and capacity are supported for longer.
Your five biological clocks
Blood-based clock including core markers of health
This clock blends routine blood results into one picture of biological age. It looks at metabolism and how major organs are working. It considers 42 markers measured simultaneously. Think lipids, glucose, kidney and liver function, iron status, inflammation, and electrolytes.
You do one blood draw. The model was trained on large human datasets, including studies like NHANES [3] with tens of thousands of participants. AI learned the complex patterns across many markers that best predict calendar age. When provided with your blood marker results, the program compares your pattern to what it has learned and estimates your biological age. The main output is the gap between your biological age and your calendar age. Age acceleration means your biological age is higher than your chronological age. Age deceleration means it is lower. Our goal is deceleration.
These markers can change with daily life, and small shifts across many results can add up to a faster or slower ageing rate. That makes the clock practical for following everyday changes. Research in longevity science also shows that when blood-based models are combined with DNA-methylation measures, they can reflect the pace of ageing and help evaluate whether changes in diet, activity, sleep, stress, and other lifestyle habits or medications are associated with favourable movement over time [4,5].
Did you know? Blood-based biological age models can differ by more than 10 years between people of the same calendar age, which helps explain why two 50-year-olds can have very different health trajectories [6,7].
Blood-based clock with expanded biochemistry panel
This broader biochemistry profile validates and refines the first estimate, using the same blood sample and 63 routinely used lab measures to provide a second, independent lens on your biology. The expanded panel improves robustness by reducing noise and pinpointing which organ systems are most linked with your current pace of ageing, ie, metabolism, cardiovascular function, liver and kidney health, endocrine balance, and inflammation.
When two aligned models point in the same direction, confidence rises: you see not only the headline biological age, but also the systems likely driving it, which makes priorities clearer and actions more targeted. Together, the blood clocks confirm the current direction of your ageing rate, highlight the main drivers, and outline practical next steps. Follow-up testing then checks whether those systems, and your biological age, are moving in a favourable direction.
What is Multi- omics? Multi-omics looks at your biology as a connected system, not in isolated pieces. It combines several “omics” [8], each showing a different layer of how your body works:
- Genomics: your DNA code, made up of genes.
- Epigenomics: switches that help control which genes are active.
- Transcriptomics: RNA activity that shows which genes are being read.
- Proteomics: proteins that do the work in cells.
- Metabolomics: small molecules that reflect energy use and chemistry.
- Microbiomics: your gut bacteria and what they produce.
We can link signals across systems and see patterns a single test might miss. This helps our clinicians identify priorities, design a more precise plan, and track how your biology responds over time.
Epigenetic clock
Your DNA doesn’t change over time, but its quality and how it’s expressed do.
The epigenetic clock measures this process by reading tiny chemical tags, known as methylation marks, that sit on your DNA. These marks act like dimmer switches, turning genes down depending on your lifestyle, stress, sleep, and environment [9]. These patterns don’t alter your genetic code. Instead, they record how life shapes your biology, giving one of the most accurate reflections of your true biological age.
Researchers build statistical models using large population datasets. They analyse DNA methylation patterns and link them to health outcomes such as disease risk and mortality [10]. Early versions of epigenetic clocks were trained to predict chronological age, the number of years you’ve been alive. Newer clocks are trained on time-to-event outcomes such as disease and mortality, which link them more closely with healthspan. Because methylation patterns change gradually across life, they act as a molecular diary of your body’s “wear and tear.” Each entry reflects how well your systems are managing stress, metabolism, inflammation, and recovery.
When your biological age is higher than your calendar age, it’s a sign that your body’s repair systems are under strain. This acceleration has been linked to a higher risk for multiple chronic conditions, from cardiovascular disease to cognitive decline. A lower biological age suggests your lifestyle is protecting your cells and that your interventions are working.
Epigenetic patterns are dynamic, and sustained changes in behaviour can be associated with shifts in biological age within months. In practice, a simple saliva-based test is used to estimate epigenetic age and highlight likely contributors to acceleration, such as inflammation or metabolic stress. A targeted intervention follows, and a repeat test several months later shows whether the pattern is moving in a favourable direction. Your epigenetic clock gives you more than just a number. It’s a feedback loop: showing, in real time, how your choices are shaping your future health.
What is DNA methylation? DNA methylation is a natural process where tiny chemical tags, called methyl groups, attach to specific spots on your DNA, most often on a cytosine base next to a guanine (known as a CpG site). These tags don’t change your DNA code. Instead, they influence how genes are read and expressed, almost like adding bookmarks that tell the cell which genes to turn on or off [11]. Methylation plays a vital role in normal development, tissue repair, and how your body adapts to stress, diet, and environment over time [12]. As you age, your pattern of methylation shifts. These changes can reflect healthy adaptation or, in some cases, risk. Abnormal methylation patterns have been linked to cancer, neurological disorders, and accelerated biological ageing. Because these patterns evolve with your life experience, scientists can now measure them to estimate your biological age, a real-time reflection of how your cells are ageing.
Inflammation clock
The inflammation clock reads immune balance over time, sometimes called inflammageing. Inflammation is essential for defence and repair, yet when low-grade activity lingers, it can strain recovery, reduce energy, and raise the risk of age-related conditions [13,14].
One window into this balance comes from Immunoglobulin G (IgG), a common antibody that carries branching sugar molecules called glycans. The pattern of these glycans can tilt immune activity toward a more pro-inflammatory or anti-inflammatory state, and it shifts with age, hormones, nutrition, sleep, stress, and environment. Measuring IgG glycans gives a snapshot of the current inflammatory state and how it may be influencing biological age [15].
The balance of glycans changes as you age, often tipping toward a more pro-inflammatory pattern. Understanding this balance helps reveal how well your immune system is adapting to stress and lifestyle demands and where you can restore equilibrium. Results are interpreted alongside blood and epigenetic data to identify the system that most needs attention, then an actionable plan is set and tracked over time.
What are glycans? Glycans are tiny, branching sugar molecules that attach to proteins and fats throughout your body, forming glycoproteins and glycolipids. They help fine-tune how those molecules function, especially in your immune system. When glycans attach to antibodies such as Immunoglobulin G (IgG) [15,16], they can subtly shift the body’s inflammatory response, either amplifying or calming it. This balance changes with age and lifestyle. Factors such as nutrition, hormone levels, sleep, stress, and environmental exposures all influence how your glycan patterns develop. Since they are shaped by both genes and lifestyle, glycans offer a unique window into how your immune system is ageing. By measuring these changes, scientists can estimate your current level of immune inflammation and track how interventions improve it over time.
Microbiome clock
The microbiome clock examines the community of microbes in your gut that influence digestion, metabolism, immunity, and the gut–brain connection. Diversity tends to decline with age, mirroring changes in immunity and energy. Stool DNA testing identifies which microbes are present and how active they are; some produce short-chain fatty acids that support gut lining and metabolic control, while others influence inflammation or hormone balance. When the ecosystem loses balance (a state called dysbiosis), strain can appear well beyond digestion, including features of metabolic syndrome, inflammatory bowel conditions, and mood-related symptoms. [17]. Dysbiosis has been linked to conditions such as metabolic syndrome, autoimmune disease, mood disorders, and inflammatory bowel conditions (IBS, IBD) [18].
Using stool DNA testing, we analyse which microbes are present in your gut and how active they are. Each species plays a different role. Some produce short-chain fatty acids that reduce inflammation and support hormone balance, while others influence metabolism, immunity, or gut–brain signaling. By understanding your microbial composition and function, we can identify which areas need support and design targeted interventions that restore harmony.
The encouraging part is that the microbiome responds quickly. Diet and lifestyle shifts can alter patterns within weeks. Profiles are linked with blood and epigenetic data to design a personalised nutrition and lifestyle plan, and retesting shows whether diversity and function are improving. Your microbiome clock reveals how your gut, brain, and metabolism work together, and how simple, consistent habits can optimise your biological resilience across time.
What is the gut microbiome? The gut microbiome is a living ecosystem inside your digestive tract, home to trillions of bacteria, fungi, and viruses that help keep your body in balance. These microbes assist with digestion, vitamin production, and immune defence, while also sending signals along the gut–brain axis that can influence mood, focus, and stress response [19]. A balanced microbiome supports smooth metabolism and strong immunity. When this balance is disrupted, known as dysbiosis, it can affect digestion, energy, and overall health. Your diet, sleep, exercise, and stress levels all shape the composition of your gut microbes. Because this ecosystem responds quickly to lifestyle change, it offers a powerful way to measure and improve your biological health over time.
From measurement to momentum
From measurement to momentum
Testing is the beginning, not the end. The five clocks are integrated with clinical findings, digital measures, and lifestyle context to build a coherent picture of how someone is ageing and where change is most likely to help. Priorities are set, actions are translated into simple steps, and goals are agreed upon. Follow-up testing then shows whether the rate of ageing and related markers are shifting in a favourable direction.
“When we measure biological age rather than simply chronological age, we can see where to intervene and track how the body actually responds.”
- Professor Andrea B. Maier
Conclusion: Your age is more than a number
Biological age shifts the focus from counting years to understanding how the body is changing today. It is measurable and, importantly, modifiable. Many of the same foundations: nutrition, activity, sleep, stress management skills, and social connection support favourable movement in these measures. The practical questions become: how to focus effort for the greatest effect, and how to check that the approach is working.
The question isn't just "What is your biological age?" but rather "What are you doing to optimise it?" Every day presents an opportunity to make choices that support cellular health and extend your healthspan. Healthy longevity medicine offers a comprehensive, personalised approach to biological age optimisation, combining advanced assessment with evidence-based interventions tailored to your unique physiology and goals.
To learn more about how biological age is assessed and tracked, request a complimentary call with the Chi Longevity team.
Reference
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