A study has found that the same gene that causes red hair can make people look younger.
The MC1R gene is critical for making melanin, which affects skin pigmentation and protects against UV radiation. There are many variants of the gene, many which cause red hair.
The study on “perceived age,” organized by the Erasmus University Medical Centre in the Netherlands and Unilever and is reported in the journal Current Biology, suggests some variants of the gene led to people looking on average two years younger than those with other forms of MC1R.
Pictures of make-up free faces of 2,693 people were independently assessed to see how old people thought they looked. Their answers were compared with the subjects’ true ages.
The scientists then looked at the subjects’ DNA to find any differences or mutations that were more common in those who looked younger. The research pointed to the MC1R gene, also nicknamed “the ginger gene.”
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Prof Manfred Kayser, from Erasmus, told BBC News: "The exciting part is we actually found the gene, and that we did find the first means we will be able to find more.
"It is exciting because this is a well known phenomenon that so far cannot be explained - why do some people look so much younger?"
The researchers could not explain why the gene has such an effect. After testing whether different variants of the been might alter skin damage from the sun, they found this was not the case.
Prof Ian Jackson, from the UK Medical Research Council's Human Genetics Unit, believes the results of the study may be confused by eye, skin and hair color.
"MC1R is the major gene involved in red hair and pale skin, and what they're trying to say is it's got an impact on making you look slightly younger that isn't to do with paler skin, but I'm not so sure,” he said.
The scientists involved in the study say they adjusted their data to account for different skin tones.
Prof Jackson said: "The question is how well are they adjusting for that – what about hair color and eye color – my gut reaction is what they're looking at is an aspect of pigmentation.
"I would suspect people who have paler pigmentation would look younger and that might be paler skin or bluer eyes or blonde or red hair."
Dr David Gunn, a senior scientist at Erasmus, hopes the continuing research will eventually lead to a product to make people look younger.
"This is the first genetic study ever of perceived age, ideally we'd want something to boost this gene for everybody," he said.
Prof Tim Frayling, from the University of Exeter, said: "This is an interesting finding that shows how genetics can influence the aging process independently of developing disease.
"However, whilst interesting, the authors admit that they need to find more genetic variation to have any chance of predicting someone's appearance from DNA alone."
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