Martires's team asked each participant about skin type, history of skin cancer, smoking, drinking habits and weight.
Skin damage was similar among the twins whether they were identical of fraternal, the researchers found. But factors outside of genes appeared highly linked with increased skin damage. These included a history of skin cancer, heavier weight and smoking. Drinking was associated with having less skin damage, Martires's group noted.
The overweight-wrinkle connection isn't so obvious, Keri said. Often, weight makes people look older but it can also hide skin damage as the weight fills out their face. "They won't look as wrinkly because the fat on their face is plumping out their skin," she said.
Salomon was surprised by one finding: that the skin cancer rate among the twins was found to be higher than it is in the general population.
"This study, with an 8 percent skin cancer rate in twins, seems high when the general population has an incidence of less than 0.5 percent. This in of itself would merit further examination to look at other [potential risk] factors, such as prenatal x-rays, prenatal sonograms and low birth weights," he noted.
Martires's team hopes people will use the findings from this study to change their own behaviors and prevent excessive skin damage from controllable environmental factors.
"The Twins Days Festival provides a rare opportunity to study a large number of twin pairs to control for genetic susceptibility," the authors wrote. "The relationships found between smoking, weight, sunscreen use, skin cancer and photodamage in these twin pairs may help to motivate the reduction of risky behaviors."
For more information on skin damage from the sun, visit the U.S. National Library of Med
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