The concept of biological age – how old your body truly is, rather than the number of years you’ve lived – is gaining mainstream attention, even featuring on shows like The Kardashians. Khloé Kardashian, aged 40, was found to have a biological age of 28 using an epigenetic clock, sparking curiosity about how we can assess our own biological age.
There are several methods to estimate biological age, each offering insights into different aspects of health and ageing. One of the simplest is perceived facial age, where how old you look can be a surprisingly accurate predictor of health and longevity. A 2009 study of twins found that those who looked older were more likely to die sooner, possibly because skin ageing reflects broader biological processes.
Another method is the ‘standing-on-one-leg’ test. Balance declines with age, and the ability to stand on one leg – especially with eyes closed – can indicate biological age. For example, managing 13 seconds with eyes closed suggests a biological age of 45. This test is practical because it reflects real-world functionality and fall risk, which is a major cause of disability in older adults.
Cardiovascular fitness, particularly VO2 max, is another strong indicator. This measure of how much oxygen the body can utilise during intense exercise declines with age, but can be improved through regular physical activity. Wearable devices or online calculators can estimate VO2 max and provide a corresponding fitness age.
Hearing ability also offers clues. High-frequency hearing loss is common with age due to deterioration of hair cells in the inner ear. While online tests exist, professional audiology assessments remain the gold standard, especially as hearing loss is linked to cognitive decline.
Finally, the most scientific methods involve blood tests and DNA-based epigenetic clocks, such as the Horvath clock, which analyses methylation patterns on DNA. These can predict age within a few years and are used in research to assess health risks. However, commercial tests can cost several hundred dollars – around £240 – and while intriguing, they currently offer limited practical advice beyond general health tips.
As science advances, these measures may help develop anti-ageing treatments and track their effectiveness. For now, simple lifestyle changes – exercise, sun protection, and healthy habits – remain the best route to a younger biological age.
