Fresh-faced actor Leonardo Di Caprio might expect a long life
People blessed with youthful faces are more likely to live to a ripe old age than those who look more than their years, work shows.
Danish scientists say appearance alone can predict survival, after they studied 387 pairs of twins.
The researchers asked nurses, trainee teachers and peers to guess the age of the twins from mug shots.
Those rated younger-looking tended to outlive their older-looking sibling, the British Medical Journal reports.
The researchers also found a plausible biological explanation for their results.
Key pieces of DNA called telomeres, which indicate the ability of cells to replicate, are also linked to how young a person looks.
A telomere of shorter length is thought to signify faster ageing and has been linked with a number of diseases.
In the study, the people who looked younger had longer telomeres.
All of the twins were in their 70s, 80s or 90s when they were photographed.
Over a seven-year follow-up the researchers, led by Professor Kaare Christensen of the University of Southern Denmark, found that the bigger the difference in perceived age within a pair, the more likely it was that the older-looking twin died first.
The age, sex and professional background of the assessors made no difference to any of the results.
Professor Christensen said it might be that people who have had a tougher life are more likely to die early - and their life is reflected in their face.
The researchers told the BMJ: "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."
Professor Tim Spector, a UK expert who has been doing his own twin research, said: "We are also finding this in our study.
"It's probably a combination of genes plus environment over a lifetime that are important."
He said the findings also show that people are good at assessing how well someone is and that doctors should eyeball their patients.
"If a patient looks older than their years then perhaps they should be more concerned," he said.