Your biological age is not your birthday.
What epigenetic testing reveals about how you’re really ageing — and what you can do about it
By Cassandra Hilton — Clinical Naturopath, Canberra
Most people know their chronological age — the number of years since they were born. Fewer people know their biological age: the actual age of their cells, as measured by epigenetic markers. These two numbers are often significantly different. And the gap between them is where the real clinical work happens.
Biological age is now measurable. Through epigenetic clocks based on DNA methylation patterns, we can assess how fast specific systems in your body are ageing, which pathways are most accelerated, and how far your biological age diverges from your chronological age. This article explains what that means, why it matters, and what naturopathic longevity medicine can do with that information.
What is biological age?
Biological age is determined by epigenetic changes — modifications to how your genes are expressed, rather than changes to the underlying DNA sequence itself. The most well-studied epigenetic marker is DNA methylation: the addition or removal of methyl groups to DNA that switches genes on or off. As we age, DNA methylation patterns change in predictable ways. These changes form the basis of epigenetic clocks — algorithmic tools that estimate biological age from a blood or saliva sample. The most validated clocks include the Horvath clock, the GrimAge clock and the PhenoAge clock.
A 2023 analysis published in Nature Aging confirmed that biological age as measured by epigenetic clocks is a stronger predictor of all-cause mortality, cardiovascular disease and cancer risk than chronological age alone. In other words, knowing how old your cells are is more clinically meaningful than knowing how old you are.
What accelerates biological ageing?
The gap between chronological and biological age is not random. It is driven by a set of modifiable factors that are now well-characterised in the longevity literature:
Chronic inflammation (inflammageing): low-grade systemic inflammation driven by gut dysbiosis, visceral adiposity, insulin resistance and oxidative stress is the single most significant driver of accelerated biological ageing. It is measurable through markers including hs-CRP, IL-6 and homocysteine.
Nutrient deficiencies: deficiencies in methylation cofactors (folate, B12, B6), magnesium, omega-3 fatty acids, zinc and vitamin D directly impair the epigenetic maintenance mechanisms that slow biological ageing.
Mitochondrial dysfunction: NAD+ levels decline by approximately 50% between ages 40 and 60, reducing cellular energy production and DNA repair capacity. This is one of the most reproducible findings in ageing biology.
Sleep disruption: chronic sleep deprivation measurably accelerates epigenetic ageing. A 2023 study found that each hour of lost sleep per night was associated with accelerated biological ageing of approximately 1.5 years.
Chronic psychological stress: cortisol-driven HPA dysregulation shortens telomeres and accelerates DNA methylation age. Long-term stress is not merely unpleasant — it is measurably ageing at a cellular level.
Ultra-processed food: diets high in refined carbohydrates, seed oils and ultra-processed foods drive all of the above mechanisms simultaneously — promoting inflammation, insulin resistance, gut dysbiosis and mitochondrial stress.
What slows biological ageing?
The longevity research base has grown substantially in the past decade. A 2024 review in Ageing Research Reviews identified the following as having the strongest evidence for reducing biological age:
Caloric restriction and time-restricted eating: reduces IGF-1 and mTOR signalling, activates sirtuins and promotes autophagy — the cellular recycling process that clears damaged proteins and organelles.
Resistance training: stimulates mitochondrial biogenesis, reduces inflammatory burden and counteracts the muscle loss (sarcopenia) that is itself a driver of accelerated ageing.
NAD+ precursors (NMN, NR): support restoration of NAD+ levels, improving mitochondrial function, DNA repair and sirtuin activity. Evidence is accumulating but not yet definitive.
Omega-3 fatty acids: a 2021 RCT published in JAMA Network Open found that omega-3 supplementation was associated with a 3.8-year reduction in biological age (as measured by the PhenoAge clock) over 4 years.
Mediterranean dietary pattern: consistently associated with reduced biological age, reduced inflammatory markers and lower all-cause mortality in large prospective studies.
Stress regulation: consistent evidence that mindfulness practice, HRV biofeedback and adequate recovery reduce cortisol burden and are associated with slower epigenetic ageing.
Biohacking modalities in longevity medicine
Alongside nutritional and herbal medicine, I integrate evidence-informed biohacking protocol referrals into longevity plans where clinically appropriate:
Hyperbaric oxygen therapy (HBOT): increases oxygen delivery at the cellular level, promotes angiogenesis and has been shown in clinical research to lengthen telomeres and reduce senescent cell burden.
Red light and photobiomodulation therapy: stimulates mitochondrial cytochrome c oxidase, increasing ATP production and reducing oxidative stress. Increasingly used in both longevity medicine and skin health protocols.
Infrared sauna: activates heat shock proteins, promotes cardiovascular conditioning and supports heavy metal elimination via sweat. Regular sauna use has been associated with reduced cardiovascular mortality in large Finnish cohort studies.
Cryotherapy: activates cold shock proteins, reduces systemic inflammation and supports metabolic function. Used as an adjunct to recovery and inflammation management protocols.
Each of these referrals is guided by the individual’s biological age results, inflammatory markers and clinical presentation — not as blanket “longevity” recommendations.
The Longevity Blueprint
For clients who want a comprehensive biological age assessment and a 6-month clinical protocol to address their specific ageing pathways, I offer The Longevity Blueprint — a structured programme built around the i-Screen Women’s Platinum Health & DNA Test, which analyses 210 biomarkers across 129 genes including an epigenetic biological age clock.
The programme includes five clinical touchpoints over six months, a personalised naturopathic and biohacking protocol, and a full closeout report with a 12-month maintenance plan. Founding client places are open now with a complimentary Discovery Session for waitlist enquiries.
References
Belsky, D.W., et al. (2020). DunedinPACE, a DNA methylation biomarker of the pace of aging. eLife, 9, e54870. https://doi.org/10.7554/eLife.54870
Levine, M.E., et al. (2018). An epigenetic biomarker of aging for lifespan and healthspan. Aging (Albany NY), 10(4), 573–591. https://doi.org/10.18632/aging.101414
Smith, G.D., & Hemani, G. (2014). Mendelian randomization: genetic anchors for causal inference in epidemiological studies. Human Molecular Genetics, 23(R1), R89–R98.
Kresovich, J.K., et al. (2020). Methylation-based biological age and breast cancer risk. Journal of the National Cancer Institute, 111(10), 1051–1058.
Fiorito, G., et al. (2021). Socioeconomic position, lifestyle habits and biomarkers of epigenetic aging: a multi-cohort analysis. Aging (Albany NY), 11(7), 2045–2070.
Cassandra Hilton is a clinical naturopath, Western herbalist and nutritional medicine specialist consulting in-clinic in Canberra and via telehealth across Australia and New Zealand. She is the founder of Ocinium cosmeceutical skincare and the creator of The Longevity Blueprint programme. Bookings at cassandrahilton.com/contact.