Why are some 60-year-olds youthful and energetic while others look aged and frail?
Part of the explanation, say researchers writing in the Cell Press journal Trends in Molecular Medicine, is different exposure to harmful substances in the environment.
These include chemicals such as benzene, cigarette smoke and even stress.
Chronological age might mean little in terms of the biological age of your body.
The researchers say we need a better understanding of the chemicals involved in ageing and the biomarkers to measure their effects.
“The rate of physiologic, or molecular, ageing differs between individuals in part because of exposure to gerontogens, environmental factors that affect ageing,” said Norman Sharpless from the University of North Carolina, Chapel Hill.
“We believe just as an understanding of carcinogens has informed cancer biology, so will an understanding of gerontogens benefit the study of ageing. By identifying and avoiding gerontogens, we will be able to influence ageing and life expectancy at a public health level.”
In the future, blood tests evaluating biomarkers of molecular age might be used to understand differences among individuals in ageing rates.
Cigarette smoke is likely the most important gerontogen, Sharpless said. Cigarettes are linked with cancers but also with other diseases associated with age.
UV radiation from the sun makes also makes us older as does chemotherapy treatment.
Sharpless cautions against making tests for molecular age available to consumers and patients directly. “The potential for mis-communication and other harm seems real,” he said.
NOW WATCH: Briefing videos
Business Insider Emails & Alerts
Site highlights each day to your inbox.