Why your birth age may not match your body’s age

We all have that one friend who looks ten years older, and another who annoyingly looks 15 years younger while all you look is a pale average of your age.

Well, researchers from New Zealand have determined, in a landmark study dubbed the Dunedin Study, why we may appear up to 22 years older than we really are.

According to the scientists, people start ageing in their 20s and at different rates.

Over 12 years, the researchers monitored over 1000 young people’s bodily functions and appearance in order to come up with their average biological ages.

“We set out to measure ageing in these relatively young people,” said first author Dan Belsky, an assistant professor of geriatrics in Duke University’s Center for Ageing in a statement.

“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,” he added.

Surprisingly, they found out that the 38-year-olds’ biological ages ranged between 28 and 61.

This means that some 38-year-olds’ bodies function as well as those of people in their late 20s while others functioned as bad as that of a 60-year-old.

“Most people think of the ageing process as something that happens late in life,” Belsky said, “but signs of ageing were already apparent in these tests over the 12 years of young adulthood: from 26 to 38.”

The team determined the biological ages by looking at how well the bodies of the respondents functioned by measuring 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, which are a proxy for the brain’s blood vessels.

“That gives us some hope that medicine might be able to slow ageing and give people more healthy active years,” said senior author Terrie Moffitt, the Nannerl O. Keohane professor of psychology and neuroscience at Duke in a statement.