Given a robust algorithm for assessing how youthful someone appears to be, and there are a few of those floating around the research community in various stages of development, it comes possible to look for correlations between a youthful appearance and various genetic variations. It isn't clear that this will lead to any practical outcome, but that is true of most fundamental research at the time it is undertaken. Possibly the most interesting aspect of the study noted here is that the correlation they found is present in multiple populations, which is a fairly rare occurrence in research into genetics and longevity.
Looking young for one's age has been a desire since time immemorial. This desire is attributable to the belief that appearance reflects health and fecundity. Indeed, perceived age predicts survival and associates with molecular markers of aging such as telomere length. Understanding the underlying molecular biology of perceived age is vital for identifying new aging therapies among other purposes, but studies are lacking thus far. As a first attempt, we performed genome-wide association studies (GWASs) of perceived facial age and wrinkling estimated from digital facial images by analyzing over eight million single-nucleotide polymorphism (SNPs) in 2,693 elderly Dutch Europeans from the Rotterdam Study. The strongest genetic associations with perceived facial age were found for multiple SNPs in the MC1R gene. This effect was enhanced for a compound heterozygosity marker constructed from four pre-selected functional MC1R SNPs, which was replicated in 599 Dutch Europeans from the Leiden Longevity Study and in 1,173 Europeans of the TwinsUK Study.
Individuals carrying the homozygote MC1R risk haplotype looked on average up to 2 years older than non-carriers. This association was independent of age, sex, skin color, and sun damage (wrinkling, pigmented spots) and persisted through different sun-exposure levels. Hence, a role for MC1R in youthful looks independent of its known melanin synthesis function is suggested. Our study uncovers the first genetic evidence explaining why some people look older for their age and provides new leads for further investigating the biological basis of how old or young people look.