Researchers from a number of institutions including Kings College London and Duke University in the US revealed that people of the same chronological age have different biological ages and are getting older with a different speed. The study was published in the Proceedings of the National Academy of Sciences on July, 6.
Scientists elaborated a list of 18 health indicators including kidney, liver and immune system function, blood pressure, cholesterol as well as assessments of metabolism, cholesterol and heart health to assess biological age of people.
They studied about 1,000 people born in 1972-73 in the town of Dunedin, New Zealand. Some of the examined 38-year-old people were, physiologically speaking, about 30 years old, while others were close to 60.
The researchers also studied the problem in process: they tested the participants when three times – when they were aged 26, 32 and 38. At the beginning of the experiment most people had similar biological age. In other words, some people were aging three years per chronological year while others were not aging at all.
That is actually a good explanation of why peers sometimes look like people of different ages. Scientists showed photos of the volunteers of the study to students of the Duke University asking them to assess the age of people on the photos. People with higher biological age seemed older to the students.
The scientists believe that environment factors are more important for ageing process than the genetic ones. According to their estimations, only 20 percent of differences in aging process are caused by genetic factors.
“There is a great deal of environmental influence,” said lead author Dan Belsky, assistant professor of geriatrics at Duke University’s Centre for Ageing, The Telegraph reports. “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.”
The team wants to continue their work and to examine the same participants when they turn 45 years old.
Scientists believe that their findings will give an opportunity to prevent health problems by people with a higher biological age.
"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," says the study.