Researchers studying genes believe they can now detect exact “physical age” by looking at a number of clues – or biomarkers – in DNA. They believe that the tests will be the first time doctors can accurately predict someone’s physiological age objectively without resorting to asking them how they feel or looking at their appearance.
The breakthrough could solve the mystery of why some 70-year-olds function at the level of those in their 50s, while others become frail sooner than would be expected. The researchers made the breakthrough by isolating the “biomarkers” of ageing in tiny worms which behave similarly to humans,
“This is the first evidence that physiological age can be predicted non-subjectively,” said Simon Melov, the lead author at Buck Institute for Age Research in California.
“This is a first step; our results were not perfect, but we were able to predict the ages of the animals 70 per cent of the time, which is far better than anything that has been done before.”
The speed at which people age depends on a number of factors including genetic inheritance, lifestyle and mental health.
Determining chronological age in both worms and humans is easy – count forward from birth. But determining physiological age has remains subjective – based on how someone looks or functions.
The team has identified for the first time biomarkers of ageing which are highly predictive of both chronological and physiological age.
The research, published in the journal Aging Cell, involved 104 worms, which had an average lifespan of three weeks.
Like humans, some of the worms remain sprightly much longer than their similarly-aged brethren, while others show signs of premature ageing – lack of symmetrical appearance, uncoordinated motion, and the need to be prodded into movement.
By genetically profiling 104 different worms – at various ages – the researchers isolated a suite of genes and biomarkers that are actively involved in the ageing process.
Now they want to extend their studies to mice and eventually humans.
“I am optimistic that we will be able to pursue this line of research further,” said Mr Melov. “Research into the biology of ageing in humans has been hampered by the lack of irrefutable biomarkers that correlate with the aging process”. He added: “I am confident that at some point there will be a non-subjective method of determining how old someone is with a high level of confidence.”