Are You Really Ageing "Well"? Why Biological Age Tests Might Not Tell You the Whole Story

The concept of “biological age” has officially entered the mainstream.

From podcasts to TikTok to wellness newsletters, everyone seems to be talking about how old they really are — not by the number of birthdays they've celebrated, but by what’s happening inside their cells. Biological age testing promises to reveal how well you're ageing, whether your efforts to eat better, sleep more, or reduce stress are “working,” and whether you're adding years to your life — or life to your years.

And the appeal is obvious. In a world that’s increasingly focused on prevention and performance, the idea of quantifying your ageing process is both empowering and seductive. A simple test, a bold number, and the reassurance (or wake-up call) that you’re either thriving or falling behind.

But here’s the thing: while the science behind biological age is fascinating, these tests might not be telling you what you really need to know.

What Is Biological Age — and Can It Be Measured?

Biological age is meant to reflect the functional condition of your body — how well your cells, tissues, and systems are holding up over time. While your chronological age is fixed, your biological age is dynamic. It can be influenced by lifestyle choices, environmental exposures, stress, nutrition, and overall health.

At the heart of most biological age tests is something called epigenetics — the study of how your environment and behaviours affect the way your genes are expressed. Specifically, many of these tests analyse DNA methylation, a process where chemical tags (called methyl groups) attach to your DNA and influence how genes are turned on or off.

These patterns change with age and have been used to build what scientists call epigenetic clocks — algorithms that estimate biological age based on how your gene expression has shifted over time.

In controlled research settings, these clocks are showing real promise. Studies have found that epigenetic age can predict risk of mortality, cardiovascular disease, and certain cancers more accurately than chronological age alone. They’re also sensitive to lifestyle changes: smoking, poor diet, and chronic stress all tend to accelerate epigenetic ageing.

But here’s where things get complicated.

Biological Age vs. Biological Insight

While the research is encouraging, biological age testing in its current commercial form is still limited — especially when used at the individual level.

For one, there’s variability in the results. Studies have shown that two samples from the same person, taken at the same time, can yield different biological age readings — sometimes differing by as much as nine years. That means your “result” may not be as precise or reliable as it appears.

There’s also no universal standard for how biological age is measured. Different companies use different algorithms, data points, and lab methods — and most don’t disclose exactly how they arrive at your number. That makes it difficult to compare results or track meaningful progress over time.

But perhaps the biggest limitation is this: knowing your biological age doesn’t tell you why it’s higher or lower than expected — or what to do about it.

You might get a number. You might even get some generic lifestyle advice. But you’re not getting clarity on which of your systems are under strain. You're not being told whether it's inflammation, insulin resistance, poor detoxification, or hormonal dysregulation that's pushing your biology in the wrong direction.

And that’s where real action begins — not with a score, but with a signal.

Curious Anyway? Here’s How to Do It Well

That said, if you’re scientifically inclined and enjoy self-tracking, biological age testing can still offer value — as long as you go into it with clear expectations and choose your test wisely.

Some options in the market are built with far more scientific rigour and transparency than others. If you’re looking for the most clinically grounded biological age tests available today, two stand out for their research foundations and methodological integrity: TruDiagnostic and Elysium Index.

TruDiagnostic, a US-based epigenetic testing company, is considered one of the more scientifically robust options currently available. Their platform draws on multiple advanced biological ageing algorithms, including Horvath’s Clock and GrimAge — both widely used in academic research. What sets TruDiagnostic apart is its depth: rather than offering just a single biological age score, the test provides a suite of related metrics, including pace of ageing, immune system ageing, telomere length approximation, and even DNA methylation-based predictions for disease risk. The company is actively involved in clinical research partnerships, with ongoing studies investigating how biological age shifts in response to interventions like diet, exercise, and fasting. It’s one of the few providers in the space that publishes its methodology and shares data with peer-reviewed institutions.

The second leading contender is the Elysium Index test, developed in collaboration with researchers from Harvard and Yale. Elysium uses the DunedinPACE clock, a model that doesn’t just estimate biological age — it measures the rate at which you're ageing, which may be an even more powerful longevity signal. This clock was trained on longitudinal data from the Dunedin Study, one of the most comprehensive life-course health studies ever conducted, following participants over decades. Elysium’s test is especially valuable if you want to understand how quickly your body is accumulating damage — and whether your current lifestyle is speeding that process up or slowing it down. The company is transparent about its scientific partnerships and backs its offerings with academic credibility, making it a trusted option for those who want to engage with biological age tracking in a meaningful way.

If you’re going to take a biological age test, these two offer the most scientific depth and repeatability currently on the market. But even then, it’s important to remember: these are still proxies, not diagnoses.

We Don’t Need a Number to Know What Works

At Biolume, we believe that personalised health shouldn’t be about vague metrics or one-size-fits-all advice. It should be about understanding what’s happening inside your body — in detail — so you can make meaningful, measurable changes.

Biological age may one day become a powerful tool. But right now, we already have access to better, more specific ways to understand how well you're ageing:

• Are you inflamed? Check hsCRP, Amyloid A, and fibrinogen.

• Are your metabolic pathways under pressure? Measure insulin, fasting glucose, HOMA-IR, and HbA1c.

• Are your detox and antioxidant systems coping? Look at GGT, LDH, and markers like homocysteine.

• Are your hormones balanced and responsive to life stage and stress? Track DHEAs, cortisol, testosterone, FSH/LH, and SHBG.

• Is your cardiovascular system at risk? Start with ApoB, Lipoprotein(a), triglycerides, and HDL.

• Are you nutritionally equipped to support cellular repair? Review vitamin D, zinc, magnesium, B12, and ferritin.

Each of these markers reveals something more precise than a broad biological age score ever could. And when tracked together — over time — they show a much clearer picture of whether you’re ageing well, and where to intervene if you’re not.

The Longevity We Care About Isn’t Just About Ageing Slowly — It’s About Ageing Intelligently

The goal isn’t to chase a younger biological age just to post it online. The real goal is to extend your healthspan — the number of years you feel vital, clear-headed, and free from disease.

And for that, you need more than a number. You need insight, context, and direction.

This is why Biolume doesn’t offer an epigenetic age test. Instead, we focus on blood biomarkers that map how your whole system is functioning — right now. Not in the abstract, but in reality. From liver and kidney health to inflammation, metabolism, and hormonal balance, we measure what matters.

Then we help you track it — and change it.

Because when you know where you stand, you know where to go next.

Longevity isn’t about hype. It’s about information — accurate, repeatable, and personalised. If you’re looking to age well, age wisely, and age with clarity, the first step isn’t chasing your biological age. It’s understanding your biology.