Can a blood test reveal how old your organs are?
A blood test can estimate the biological age of individual organs, and accelerated ageing is clearly associated with more illness and a higher risk of death. The technology is promising but not yet available as a routine clinical test.
Proteins that specific organs release into the blood reveal how aged those organs are. Using machine learning, researchers can estimate the biological age of 11 major organs separately from a single blood sample. This worked consistently across five independent groups totalling more than 5,600 participants.
The findings are striking. People with one severely accelerated-ageing organ had a 20 to 50 percent higher risk of dying than people whose organs were in line with their calendar age. For an accelerated-ageing heart, the risk of heart failure rose by as much as 250 percent. And accelerated ageing of the brain and blood vessels predicted the likelihood of Alzheimer's disease just as well as the best existing blood tests. About one in five people turned out to have one severely aged organ; in around 1.7 percent, several organs were affected at the same time.
A different approach, measuring chemical changes in DNA that control how active genes are, gives a similar estimate of biological age. This idea has been tested on samples from more than fifty types of healthy tissue. Many studies show that people who are biologically ageing faster than their calendar age suggests fall ill more often and die earlier, even when they are still young and have no symptoms yet. A specially developed test for the rate of ageing proved particularly reliable in capturing this.
Measurable differences in how quickly organ systems decline are already visible in people in their twenties and thirties. Young adults who were ageing biologically faster performed worse on thinking and physical tasks and also looked older than their peers. This makes the measurement relevant well beyond traditional older-age medicine.
One note of caution about the blood-protein study: key researchers are co-founders of and shareholders in companies that want to commercialise this technology, and a patent has been applied for. That is worth bearing in mind when reading the findings of that particular study.
The main evidence comes from one large study (more than 5,600 participants across five groups) on organ-specific proteins in the blood, supported by a series of evaluating studies and a separate study in young adults. The researchers behind the protein study have commercial interests in the technology, which is relevant when weighing those specific results. The link between a higher biological age and greater illness and early death recurs across multiple independent research groups, but no single study proves that accelerated ageing is itself the cause: it is also possible that diseased organs simply appear to measure as aged.
Can you see your biological age in your blood pressure?
A rising systolic blood pressure and a widening gap between the upper and lower numbers are recognisable signs of vascular ageing, but a truly reliable picture of your biological vascular age requires additional measurements that a general practitioner does not routinely perform.
Which blood markers can tell you how fast you are biologically ageing?
Blood markers such as protein profiles, DNA-tag patterns, telomere length and standard inflammation markers each offer their own indication of how fast you are biologically ageing. The specialised tests are not yet routine GP care, but your standard blood work already contains useful clues.
Can you tell someone's biological age from their face?
Your face does emit biological signals, but it is too limited and too variable to measure your biological age accurately. Take facial ageing seriously as a possible indicator, but do not rely on it as a measure of your health.
How can I measure my biological age?
DNA clocks, and GrimAge in particular, give the most reliable picture of your biological age. These measurement methods are currently used mainly in research.
How reliable is a protein test for measuring your biological age?
A protein test is a promising and now reasonably well-supported way to measure biological ageing, particularly as a predictor of disease and death, but its translation into personal use is still very much in development.
Does the PhenoAge test measure your biological age with standard blood values?
Standard blood test results can provide an estimate of your biological age through PhenoAge, and that estimate predicts health risks measurably better than calendar age alone. The score is not a definitive measure, but it does provide meaningful information about how quickly your body is ageing.