Find some people can halt, reverse ageing process during their thirties
IT seems like something from the realm of science-fiction. Some people can halt - and even reverse - the ageing process in their thirties, scientists say.
A team who measured the effects of getting older on nearly 1,000 men and women found that over a 12-year period, three of the participants had shown no deterioration.
The study was published in the Proceedings of the National Academy of Science journal.
Duke researchers analysed medical data from almost a thousand 38 year olds. While some appeared medically in their late 20s, some seemed almost 60.
They had biologically aged zero years, and had even begun to look younger. These people may hold the key to developing what would in effect be a fountain of youth, say the team from universities in Britain, the US, Israel and New Zealand.
While some cheated the ageing process, however, others were found to have aged biologically by three years for each calendar year.
The study focused on 954 people in the New Zealand city of Dunedin who have been tracked for several years.
The researchers devised a measure called 'biological age' to assess how worn out the participants' bodies were internally.
HOW THEY DID IT
The data comes from the Dunedin Study, a landmark longitudinal study that has tracked more than a thousand people born in 1972-73 in the same town from birth to the present.
Health measures like blood pressure and liver function have been taken regularly, along with interviews and other assessments.
Belsky said the progress of aging shows in human organs just as it does in eyes, joints and hair, but sooner.
So as part of their regular reassessment of the study population at age 38 in 2011, the team measured the functions of kidneys, liver, lungs, metabolic and immune systems.
They also measured High Density Lipo-protein (HDL)/'good' cholesterol, cardiorespiratory fitness, lung function and the length of the telomeres - protective caps at the end of chromosomes that have been found to shorten with age.
Using their assessment, they found some of the 38-year-olds had a body age more like 60. A few were up to eight years 'younger' than their real age. And three had not 'aged' at all over the tested period.
Further tests revealed that those who seemed older on the inside also appeared older to others who were asked to guess their age.
The authors wrote in the Proceedings of the National Academy of Science journal that three of the participants appeared "to grow physiologically younger during their thirties … Study of such individuals may reveal molecular and behavioural pathways to rejuvenation."
Lead researcher Dan Belsky, geriatrics professor at Duke University in the US, said: "Most studies of ageing look at seniors, but if we want to be able to prevent age-related disease, we're going to have to start studying ageing in young people."
The scientists measured the function of kidneys, lungs, the metabolic and immune systems, and dental health. They also measured telomeres - the 'caps' on the end of DNA strands that stop them unravelling which have been found to shorten with age.
A biological age of 40, for example, meant that person was aging at a rate of 1.2 years per year over the 12 years the study examined.
This allowed them to calculate a 'biological age' for each participant. The biological ages ranged from under 30 to nearly 60, even though all the test subjects were 38.
Those who were more advanced in biological ageing also scored worse on balance and co-ordination tests usually given to over-60s, and had more difficulty with activities such as walking upstairs.
WHAT THEY FOUND
Study members who appeared to be more advanced in biological aging also scored worse on tests typically given to people over 60, including tests of balance and coordination and solving unfamiliar problems.
The biologically older individuals also reported having more difficulties with physical functioning than their peers, such as walking up stairs. Participants who were biologically older on the inside also appeared older to the college students.
The researchers say the ultimate goal is to be able to intervene in the ageing process itself, rather than addressing killers such as heart disease or cancer in isolation.
Belsky said: "As we get older, our risk grows for all kinds of different diseases. To prevent multiple diseases simultaneously, ageing itself has to be the target. Otherwise, it's a game of whack-a-mole."
Prof. Terrie Moffitt, also of Duke University and King's College, London, said there was nothing unique about Dunedin and the pattern is likely to be repeated in similar populations elsewhere.
She said that smoking and serious mental illness can speed up the ageing process, while intelligence seems to keep the body young.
This may be because a healthy brain is a sign of a healthy body, or because intelligent people have less physically demanding jobs, live in less polluted areas and take more care of their health.
The researchers also believe genes play a role - and pinning this down could lead to new anti-ageing drugs. Until then, said Professor Belsky, the best way to hold back time is to eat well and exercise.