LONDON: Scientists have developed a way of testing how well, or badly, your body is ageing.
They say it could help predict when a person will die, identify those at high-risk of dementia and could affect medicine, pensions and insurance.
The team at King's College London say looking at "biological age" is more useful than using a date of birth.
However, the work, published in Genome Biology, provides no clues as to how to slow the ageing process.
The test looks for an "ageing signature" in your body's cells by comparing the behaviour of 150 genes.
It was developed by initially comparing 54,000 markers of gene activity in healthy, but largely sedentary, 25 and 65-year-olds and then whittling them down to a final 150.
Prof Jamie Timmons, from King's College London, told the BBC: "There's a healthy ageing signature that's common to all our tissues, and it appears to be prognostic for a number of things including longevity and cognitive decline.
"It looks like from the age of 40 onwards you can use this to give guidance on how well an individual is ageing."
The team said "health" and "age" were two separate entities.
And while some lifestyle decisions, like spending all day on the sofa, could be bad for your health they do not appear to affect the speed your body ages.
The team believe combining lifestyle factors and your biological age would give a more accurate picture of your health.
The researchers tried the test out on samples from a group of 70-year-old men in Sweden.
They worked out who was ageing well and who was ageing very rapidly and were able to predict who would die in the next few years.
"You could actually pick out people who had almost no chance of being dead, and you have people who had an almost 45 percent chance of being dead," Prof Timmons told the BBC.
There are plans to pilot the test in organ transplants in the UK to see if people who are technically old, but have a young "biological age", can still donate organs safely.
The researchers say it could also alter cancer screening, with people who are ageing rapidly needing to be screened at a younger age.
Prof Simmons said the test would also form a "useful tool" in predicting the onset of dementia.
He said that it could be used in conjunction with other checks to identify those at highest risk of developing the neurodegenerative disease and to enroll them in clinical trials.
QNA
