A single gene may influence whether a person looks younger or older than they are — with some variants adding about two years to a person’s appearance.
Why it matters:
It might sound superficial, but there is actually medical value in studying so-called perceived age.
“Perceived age can be used to assess a person’s overall health — in the clinic as well as epidemiological studies — similar to self-reported health,” said Dr. Kaare Christensen, director of the Danish Aging Research Center, who was not involved in the study. “In terms of mortality, it is more dangerous to look one year older than to be one year older.”
The nitty gritty:
Researchers tapped a previously compiled database of Dutch residents to extract photos and genetic data on nearly 2,700 people. They showed these photos to employees of Unilever — one of the study’s funders and where some of the participating researchers were based — and asked them to select a five-year age range for the subject.
When researchers compared these ratings with the subjects’ genomes, they found that changes in one gene, called MC1R, were most strongly linked to a person’s perceived age. Certain versions of MC1R made people look on average two years older than other versions, regardless of the subject’s age, sex, skin color, sun exposure, wrinkles, and pigmented spots. Researchers published the findings Thursday in Current Biology.
But keep in mind:
The analysis was only run on white Europeans. “We decided to exclude nonwhites because it made the analyses too noisy,” said lead researcher David Gunn, senior scientist at Unilever. So its findings may not be generalizable to other populations.
Gunn also said he recognizes that a person’s perceived age can depend on who’s doing the perceiving. To try to minimize that noise, the group had an average of 27 people review each photo.
“We were encouraged by data that showed that once you started taking responses from larger groups, the more you get reproducible outcomes,” Gunn said. “We didn’t know if we could continue the study if we couldn’t get consistent numbers on the perceived age.”
Gunn said he now wants to find out exactly how MC1R affects facial aging. He also wants to expand the study the gene’s effect with other racial groups, which were not included in this study.