A Japanese team has just developed a
urinary aging clock which reads molecular signals in urine capable of estimating the age of an organism almost as well as a sophisticated blood test.
Behind this concept, a key idea: your biological age may be different from your age on the identity card, and this gap relates to the risk of chronic diseases and premature death. For a long time, identifying this inner age required expensive DNA tests. Urine may soon make all of this easier.
How a Urine Test Reads Your Inner Age
In a study published in the journal npj Agingresearchers from Craif Inc. and Nagoya University analyzed urine samples from 6,331 Japanese adults participating in cancer screening. They isolated hundreds of microRNAs, these small molecules that regulate gene expression and change with age, from urinary extracellular vesicles, then trained an artificial intelligence algorithm, LightGBM, on 407 microRNAs judged to be the most informative.
The model was trained on 2,400 people, then tested on two other groups of 2,840 and 1,091 individuals. The predicted “urinary age” deviated by an average of only 5.1 years in the training set, 4.5 years in the first test, and 4.4 years in the second. The urinary clock remains a little less precise than DNA methylation clocks, but it does better than several clocks based on blood microRNAs or mRNAs, for a completely non-invasive test.
Accelerated aging, diabetes and health risk
The researchers defined an indicator called ΔAge, the difference between the age predicted by urinary microRNAs and chronological age. A positive ΔAge reflects a accelerated agingalready linked, for other biological clocks, to an increased risk of morbidity and mortality. The 20 most determining microRNAs are found enriched in pathways of cellular senescence, bone remodeling, osteoclast regulation, marginal zone B cell differentiation, but also in processes of apoptosis and mitochondrial dysfunction.
When they crossed ΔAge with the declared diseases, one result stood out clearly: only type 2 diabetes was associated with a significant increase in ΔAge. The effect was marked in women aged 50 to 69 and men aged 50 to 79. In other words, in these people, the urine reflects the image of an organism older than the marital status, consistent with the already known metabolic and cardiovascular complications of diabetes.
A promising, but still experimental, “urine aging clock”
The authors emphasize that this “urinary clock” provides an overall indicator of risk, not a diagnosis of a specific disease, much less a countdown on the number of years remaining. Estimates become less reliable before 25 years and after 80 years, and hydration or collection conditions can influence the results despite quality controls. The sequencing data are not public and independent validation, on other populations, remains essential before considering routine clinical use.
If these steps are confirmed, a urine test biological age or a biological age urine test could one day be integrated into health checkups to stratify risks, detect accelerated aging linked to factors like diabetes, and track the effect of lifestyle interventions or treatments. The simplicity of urine sampling, compared to taking blood, opens the way to much more accessible aging monitoring devices.
Still experimental, this urinary clock does not predict the future or future diseases, but it opens up a fascinating prospect: that of simple, non-invasive and accessible aging monitoring, capable of signaling much earlier than expected when the body is starting to get ahead… in the wrong way.