People who look young for their age enjoy a longer life than those who look older than their years, a new study has shown.
The study, conducted by a team from the Institute of Public Health at the University of Southern Denmark, observed 387 twin pairs, aged between 70 and 99, to reach the conclusion.
Three groups of people assessed the photographs of the twins at the old age.
The groups included geriatric nurses, older women and young male student teachers.
All the pictures were mixed up, with each twin assessed on a different day to their sibling, reports the Independent.
After a period of seven years, experts noted that the bigger the difference in perceived age within a pair, the more likely it was that the older-looking twin died first.
The study also showed perceived age was linked with an important molecular biomarker of ageing called telomeres.
A telomere of shorter length is believed to signify faster ageing and has been linked to a number of diseases, such as cancer.
People who looked young in the study had longer telomeres.
The study concluded: "Perceived age, which is widely used by clinicians as a general indication of a patient's health, is a robust biomarker of ageing that predicts survival among those aged over 70, and correlates with important functional and molecular ageing phenotypes."
The study has published online in the British Medical Journal.