Why does it seem some people age faster than others?

How many times have you heard some impossibly youthful looking person insist it’s their genes that make them look great?

Well, a new study suggests they’re not just being coy (or lying about their age). Scientists from Duke University in North Carolina embarked upon a study to find out more about the biology of ageing, and discovered that people age at vastly differing rates.

The researchers used 18 physiological markers, including measures of kidney and liver function, cholesterol levels, cardiovascular fitness and the lengths of teleomeres, which are protective caps that sit on the ends of chromosomes, to assess the biological the ages of participants from the Dunedin study, a major investigation that has tracked around 1000 New Zealanders born in 1972 or 1973.

The markers were measured when the volunteers were aged 26, then 32, and finally at the age of 38, to produce a “pace of ageing” figure.

While most of the now 38-year-olds had similar biological and actual ages, some were far “younger” and others much “older”. At the extremes, one person had a biological age of 61 years old, while another was only 28.

Daniel Belsky at Duke University in North Carolina said studying people in their late 30s provided a new insight into the biological changes that drive ageing rather the biological changes associated with age-related disease.

“It’s becoming increasingly clear that ageing is really the cause of much of the disease and disability burden we face, but our existing science is based on ageing in older people who already have a lot of age-related diseases,” he said.

Biologically older people had more difficulty with tests involving balancing, coordination, mental tasks and tasks like climbing stairs.

Meanwhile, on the surface, it turns out your biological age is more in line with how people see you.

The researchers showed photos of the participants to students and asked them to guess the people’s ages. Those with older biological ages were consistently perceived to be older than their years.

The next phase of the research is to examine how lifestyle, medical history, family circumstances, and stressful events might affect the speed at which people age.

The goal is to target ageing instead of the various diseases people are increasingly likely to develop as they age.

“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,” Belsky said.

Have you noticed some people age faster or slower than others? Where do you sit on the spectrum?