A recent study published in the British Medical Journal found that how old you look corresponds with your health.
Over a 7-year period, a team of researchers lead by Professor Kaare Christensen of the University of Southern Denmark studied 387 sets of twins. They asked nurses, trainees and peers to guess the age of twins in the photos.
The team found the older-looking twin was more likely to die first, based on the perceived distance in age.
"When assessing health, physicians traditionally compare perceived and chronological age, and for adult patients the expression 'looking old for your age' is an indicator of poor health," the researchers wrote in the report.
Key pieces of DNA called telomers--which indicate a cell's ability to replicate- are also linked to how young a person looks. The researches found that shorter strands of telomers mean faster ageing and are linked to other age-related diseases.
The study also noted the centuries-old practices of using perceived age as an indicator of health is a useful clinical approach considering perceived age is based on a number of indicators in addition to facial appearance.
Specific health hazards, such as smoking, sun exposure, low socioeconomic status and high depression scores were all associated with a higher perceived age in the study.