Next time somebody compliments you on your youthful good looks, don't give your moisturizer the credit - it doesn't work, and you're really not worth it.
No, an international team has for the first time identified definitive genetic variants, located near a gene called TERC, that cause some people to look older than their age.
The researchers analyzed more than 500,000 genetic variations across the entire human genome to identify the variants.
"There is accumulating evidence that the risk of age-associated diseases including heart disease and some types of cancers are more closely related to biological rather than chronological age," said
Professor Nilesh Samanithe of the University of Leicester.
His team studied structures called telomeres within a person's chromosomes. Individuals are born with telomeres of a certain length, and in many cells telomeres shorten as the cells divide and age. Telomere length is therefore considered a marker of biological ageing.
"In this study what we found was that those individuals carrying a particular genetic variant had shorter telomeres - ie, looked biologically older," said Samanithe.
"Given the association of shorter telomeres with age-associated diseases, the finding raises the question whether individuals carrying the variant are at greater risk of developing such diseases."
Professor Tim Spector from King's College London explained that the TERC gene was already known to play an important role in maintaining telomere length.
"What our study suggests is that some people are genetically programmed to age at a faster rate," he said.
"The effect was quite considerable in those with the variant, equivalent to between three and four years of 'biological aging' as measured by telomere length loss."
The research appears in Nature Genetics.