Measuring Your Body’s True Age: A Guide to Biological Age Testing

Why Measuring Biological Age Matters

Jordan Bortz and colleagues at Humanity Inc. emphasize that measuring biological age offers two key benefits: evaluating the effectiveness of aging interventions and making better predictions of age-related conditions, including mortality risk. Essentially, biological age gives you a more accurate picture of your health than simply counting candles on your birthday cake.

The concept isn't just academic, biological age estimates can detect differences even in young, healthy individuals before disease or visible signs of accelerated aging appear. This early detection creates opportunities for intervention that might help extend both lifespan and healthspan (the healthy, functional years of life).

The Foundation: Clinical Measurements

Your blood pressure reading resembles checking the pressure in your home's water system. Too high, and you're straining the pipes. Too low, and the flow becomes inadequate. Resting heart rate offers insights into your cardiovascular efficiency. Think of it as measuring how hard your heart's engine works to maintain idle speed. Body composition tells us about metabolic health, excess weight around the midsection can accelerate ageing processes throughout your entire system.

Blood: The Body's Information Highway

But the real revelations come from blood tests. Recent research from the UK Biobank, involving over 300,000 participants, identified key markers that predict not just how we're ageing, but how quickly we might be approaching health complications.

The inflammatory markers fascinate me most. When we measure C-reactive protein and interleukin-6, we're essentially checking how much "repair work" your body is conducting. Some inflammation is normal, it's your body's maintenance crew. But when too many crews are working overtime, it suggests accelerated ageing.

The metabolic markers, fasting glucose, insulin levels, HbA1c, reveal how efficiently your body processes fuel. When these levels climb, it's like an engine running too rich, potentially causing premature wear throughout the system.

Among the most predictive markers identified were cystatin C (reflecting kidney function decline), red blood cell distribution width, and HbA1c. According to Jordan Bortz and colleagues at Humanity Inc., these markers collectively predict mortality risk with remarkable accuracy, their model provided an 11% increase in predictive value over previous approaches.

Beyond the Basics: Advanced Testing

• DNA Methylation: Reading Cellular Bookmarks The most sophisticated biological age testing happens at the molecular level. DNA methylation patterns, chemical modifications that change with age, have emerged as powerful predictors. I like to explain this to clients by comparing their genome to a vast library.

"Imagine your DNA as thousands of books," I tell them. "Methylation patterns are like bookmarks and margin notes accumulated over time, indicating which chapters should be read or ignored. Scientists can analyse these patterns to determine how well your cellular library is being maintained."

The epigenetic clocks, Horvath's clock, GrimAge, PhenoAge, analyse specific sites where methylation typically changes with age. It's remarkable science, though the tests remain expensive and aren't yet part of routine healthcare.

• Telomeres: The Cellular Hourglass Telomeres, those protective caps at chromosome ends, were among the first proposed biological age markers. Measuring their length is like checking the remaining length of a burning candle, it indicates how much cellular lifespan remains. However, I've learned to temper enthusiasm about telomere testing. Recent research suggests its predictive power may be less robust than once hoped. As researchers Vaiserman and Krasnienkov note, telomere length "can only allow a rough estimate of ageing rate and can hardly be regarded as a clinically important risk marker."

Function Over Form: Performance Testing

Sometimes the most revealing tests are surprisingly simple. Grip's strength, a basic measurement taken with a simple device, correlates remarkably well with overall health and longevity. It's like testing a building's structural integrity, weak grip strength often signals accelerated ageing throughout the body.

VO2 max testing measures your body's maximum oxygen utilisation during exercise. This cardiovascular fitness marker is like measuring your engine's peak performance. Higher VO2 max typically indicates younger biological age, and the test involves nothing more complex than exercising on a treadmill whilst wearing monitoring equipment. Cognitive testing reveals how well your brain is maintaining itself. Memory tests, processing speed assessments, and problem-solving abilities all provide clues about neurological ageing compared to age-matched peers.

Everything AI

Modern technology has opened fascinating new possibilities. Artificial intelligence algorithms can now analyse combinations of biomarkers, physical measurements, and even facial photographs to estimate biological age. But here's where I counsel caution. Facial analysis can be misleading due to cosmetic procedures, skincare treatments, or aesthetic interventions. The most reliable AI-based assessments focus on internal biomarkers and functional measurements rather than external appearances. These systems can process vast amounts of data to identify ageing patterns, but they're tools for guidance, not gospel.

What can you do now?

After years of working with clients on biological age optimisation, I've learned that the most effective approach combines accessible testing with actionable insights. You don't need to spend thousands on advanced molecular testing to gain valuable information about your biological age.

• Start with Standard Blood Tests Even routine blood panels can provide insights into biological ageing processes. I always recommend that clients request tests including kidney function markers, inflammation indicators, blood sugar control measures, and liver function assessments.
• Consider Specialised Testing Several companies now offer biological age tests using blood biomarkers. Look for those including cystatin C and other key markers identified in recent research. DNA methylation testing is available commercially, though it tends to be more expensive than blood-based alternatives.
• Home Monitoring Options Whilst not comprehensive biological age tests, devices tracking heart rate variability, sleep quality, and recovery can provide useful data about physiological functioning. I've seen clients gain valuable insights from consistent monitoring of these metrics, and others who fell into the “tracker-trap’ developing orthorexia, an unhealthy obsession with eating "perfectly" or exercising "optimally." I wrote more on this here: The Tracker Trap

The real value of biological age testing lies not in the number itself but in the insights it provides for improving health. Over the years, I've watched clients successfully reduce their biological age through targeted lifestyle changes.

Regular physical activity consistently shows powerful anti-ageing effects across multiple biological systems. Mediterranean-style diets, caloric restriction, and adequate protein intake can positively influence biological ageing markers. Quality sleep proves essential for cellular repair processes, whilst chronic stress accelerates biological ageing.

Perhaps most importantly, strong social relationships have been linked to slower biological ageing. The connection between loneliness and accelerated ageing is profound, something I've observed repeatedly in my practice.

The Encouraging Truth

Here's what I find most hopeful about biological age testing: it reveals our agency in the ageing process. Unlike chronological age, biological age can move in both directions.

Understanding your biological age test results requires context and professional guidance. Results should be viewed as a snapshot of your current health status and a guide for intervention rather than a definitive prediction of lifespan. These tests are tools for optimisation, not crystal balls. Nevertheless, they offer something precious: powerful insights that can guide lifestyle choices and potentially identify health issues before they manifest as disease. By understanding and tracking your biological age, you gain control over not just how long you might live, but how well you'll live those years.

Resources: Linpei Jia, Weiguang Zhang & Xiangmei Chen (2017) Common methods of biological age estimation, Clinical Interventions in Aging, , 759-772, DOI: 10.2147/CIA.S134921

Vaiserman A and Krasnienkov D (2021) Telomere Length as a Marker of Biological Age: State-of-the-Art, Open Issues, and Future Perspectives. Front. Genet. 11:630186. doi: 10.3389/fgene.2020.630186

Bortz, J., Guariglia, A., Klaric, L. et al. Biological age estimation using circulating blood biomarkers. Commun Biol 6, 1089 (2023).Link