It has been found in a detailed study of biological ageing that some people grow older three times faster than according to their birthdays. The study has been published in Proceedings of the National Academy of Sciences.

As per the study, it appears others have genes or environmental influences that make them look younger compared to those who quickly grow old. It was found in the study that among a group of 38-year-olds who participated in the research, biological age was ranging from 28 to 61.

The researchers found the rate at which a person is ageing by drawing up a panel of 18 measures. There were many tests included in the research such as tests of liver, kidney, lung and immune system function in addition to assessments of cholesterol, metabolism, heart health, lung function, and the length of telomeres that are caps on the ends of chromosomes and helps protect them.

The condition of small capillaries at the back of the eye was also observed by the scientists. This helped know about the condition of blood vessels in the brain. According to lead scientist Dr Dan Belsky, from the Duke University Center for Ageing in North Carolina, “We set out to measure ageing in these relatively young people. 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”.

It was found that some of the 38-year-olds were ageing very quickly, so much so that their "biological age" was heading towards retirement.