Some of the people you went to high school with look like they havent aged a day since graduation. Others look like they could already be in a retirement home.
A long-term health study of about 1,000 young adults in New Zealand now has some of the answers to uneven aging, as published today in the Proceedings of the National Academy of Sciences.
The group was analyzed for 12 years, from the age of 26 to 38. A set of 18 biological markers were used to determine the relative pace of aging. Factors included traditional blood pressure and liver function, but also added function of other vital organs such as the kidneys, lungs, metabolic and immune systems, as well as the length of their telomeres, the ends of the chromosomes which shrunk with age.
The 38 year olds varied from biological aging under 30 years, to nearly 60 years of relative age, according to the markers which might point a way to offsetting the years.
We set out to measure aging in these relatively young people, said Daniel Belsky, an assistant professor of geriatrics at Duke Universitys Center for Aging, and the first author. Most studies of aging look at seniors, but if we want to be able to prevent age-related disease, were going to have to start studying aging in young people.
Most of the group in the Dunedin Study, which tracked people in the same New Zealand town born in 1972 and 1973, were aging at an average rate of about one year per year. But some aged at a rate of zero years and for the rate was as great as three biological years per 12 calendar months, they found.
Those who aged faster within were also considered older-appearing to college students, and also had corresponding physical and cognition difficulties compared with their younger counterparts.
It wasnt all genes, the scientists concluded pointing to previous twin studies which find only 20 percent of aging is attributable to natural inheritance, they found.
That gives us some hope that medicine might be able to slow aging and give people more healthy active years, said Terrie Moffitt, a Duke professor of psychology and neuroscience, and senior author of the study.
Richie Poulton, the Dunedin Study director, says that being able to detect accelerated aging at an early stage paves the way for proactive treatment of age-related ailments.
Currently, we are largely stuck in an ambulance at the bottom of the cliff situation, Poulton said. And by 2050, the world population aged 80 years and over will approach 400 million people, so we are facing an enormous global burden of disease and disability unless we can extend healthy lifespans.