Are you looking old lately? You can blame the redhead gene!
A new study from researchers in the Netherlands has found a genetic basis for why some people look older than their age while others look younger.
The study involved 2,693 Dutch European subjects whose faces were analyzed by a 3D image assessment system that looked for more than 25 criteria to come up with a perceived age, based on themes such as pigmented spots, wrinkles, skin tone and face shape. The results were then correlated with the subjects’ genetic data, indicating that those individuals carrying a genetic variant of the MC1R gene -a variant that is also responsible for red hair and fair skin- were observed to look on average two years older than their actual age.
“This study is the first to identify genetic variants significantly associated with perceived age,” say the study’s authors, whose research is published in the journal Current Biology. “We provide evidence that, of eight million tested, DNA variants in the MC1R gene had the strongest association with perceived age in subjects of European ancestry.”
The MC1R gene is known to be a factor in biological processes such as inflammation and DNA damage repair, suggesting to researchers that it’s the effect that MC1R has on these cellular processes that connects it with perceptions of age.
The study also found an association between perceived age and a subject’s actual health and mortality, showing that there may be a biological underpinning for why some people look younger than their age (and why others look older). “Perceived age predicts survival,” say the study’s authors, “Understanding the underlying molecular biology of perceived age is vital for identifying new aging therapies among other purposes.”
But even though the same genetic variant of MC1R also produces red hair and fair skin, the study’s authors caution against drawing the conclusion that redheads will on average look two years older than their actual age. There are countless parts at play in determining perceptions of age, many of them environmental in nature, says David Gunn, co-author of the study. “I don’t want people to worry if they have got red hair. It is just one factor and there are many other factors,” says Gunn. “Genes’ effects are not fixed, they don’t determine our aging, they interact with what we do.”
The red hair-causing variant of MC1R (called MC1R-RHC) has been shown to play a role in the development of melanoma skin cancer, according to a study conducted at Harvard Medical School, a result which does in fact draw a link between having red hair and an increased risk of developing skin cancer. Researchers studying the MC1R gene receptor found that the RHC mutation of this gene which creates the red hair phenotype also disrupts the work of a tumor suppressor gene called PTEN and boosts the cell proliferation, thereby supporting the development of cancerous cells. Originating in skin pigment-producing cells, melanoma is the least common but most lethal form of skin cancer, making up 75 per cent of all skin cancer deaths. Two types of ultraviolet radiation – UVA and UVB – support the mutation of the cell’s DNA and lead to melanoma.
Globally, it’s estimated that one to two per cent of the population has red hair. That number rises to two to six per cent in the Northern Hemisphere and is at its highest in Scotland where 13 per cent of people are redheads.
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