I was 35 when I took the test. And my results suggested that my biological age was 35 too. That indicates I’m aging at a normal rate compared with other people we have data for. But the company that ran the test has updated its offering since then. A couple of months ago, it reanalyzed my results to give me an individual biological age for each of nine systems, including my brain, liver, heart, and blood.
I was disappointed when I learned last year that despite a plant-based diet and regular yoga, I am no more biologically youthful than average. So imagine how upsetting it was to learn that the biological age of my brain is four years above my chronological age. My liver is a shocking seven years older. Yes, I’m British, but I don’t think I drink that much. How much should we read into results like this?
The first aging clocks, developed around a decade ago, were designed to analyze epigenetic markers on DNA from saliva samples. These markers are essentially chemicals that attach to our DNA and control how our genes make proteins. Research has shown that the patterns of these markers align with age. Scientists can train algorithms to estimate a person’s age just by analyzing them.
Since then, scientists have improved on the technology. New clocks incorporate not only your epigenetic markers but a range of other health biomarkers, such as blood sugar levels and white blood cell count. These tests may give us some idea of a person’s biological age—not just how many birthdays have passed, but how many years of healthy life might lie ahead.
Today, there are plenty of aging clocks out there. Some have been developed for specific organs, and others have been designed for particular animal species. Some analyze blood samples, and others assess the microbiome. The test I took last year, developed by the company Elysium, uses saliva samples and assesses epigenetic markers.
The team at Elysium has since expanded the remit of the test. Send off a miniature tube of saliva, and you’ll soon be told not only your overall biological age, but the specific biological ages of your heart, brain, liver, kidneys, and blood; your metabolic, immune, and hormonal systems; and what they call your inflammation system.