An international research team from the US, UK, Israel and New Zealand found a way to measure the ageing process in young adults - a much younger population than is usually tested in ageing studies.
Working with study participants age 26 to 38, scientists identified factors that can determine whether people are ageing faster or slower than their peers, and to quantify both their biological age and how quickly they are ageing.
The researchers showed that even among young adults, a person’s biological age may differ by many years from their actual chronological age.
For example, among 38-year-olds studied, the participants’ biological age was found to range from under 30 years old, to nearly 60 years old.
That means some participants’ biological age was more than 20 years older than their birth certificates indicated.
“This research shows that age-related decline is already happening in young adults who are decades away from developing age-related <g data-gr-id="33">diseases,</g> and that we can measure it,” said Dr Salomon Israel, from the Hebrew University of Jerusalem’s Department of Psychology, and co-author of the study.
The data comes from the Dunedin Study, a long-term health study in New Zealand that seeks clues to the ageing process. The study tracks over a thousand people born in 1972-73 from birth to the present, using health measures like blood pressure, liver function, and interviews.
As part of their regular reassessment of the study population in 2011, the team measured the functions of kidneys, liver, lungs, metabolic and immune systems.
They also measured HDL 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.
The study also measures dental health and the condition of the tiny blood vessels at the back of the eyes, a proxy for the brain’s blood vessels.
Researchers determined a biological age for each participant. They then looked at 18 biomarkers that were measured when the participants were age 26, and again when they were 32 and 38.