Yolanda Helfrich, MD, and colleagues studied 82 people at the University of Michigan at Ann Arbor's dermatology clinic.
Participants were 22-91 years old (average age: 56). Most were white; 41 had a history of smoking.
A medical photographer took pictures of each participant's upper inner arm.
The photos were reviewed by three judges (two dermatology residents and one medical student) who didn't know which participants were smokers.
The judges used a nine-point scale developed by Helfrich's team. A rating of 0 indicated no fine wrinkling; severe fine wrinkling yielded the maximum score of 8.
Smoking and Wrinkles
Nearly two-thirds of the participants had low wrinkle scores ranging from 0-2 points. Smokers generally had the highest scores, indicating deeper wrinkles.
The wrinkle risk was particularly strong for people who had smoked heavily for many years.
"We examined nonfacial skin that was protected from the sun, and found that the total number of packs of cigarettes smoked per day and the total years a person has smoked were linked with the amount of skin damage a person experienced," Helfrich says in a University of Michigan news release.
The study doesn't prove that smoking caused or worsened wrinkles. But the results held when the researchers took other factors, including participants' age, into account.
The study appears in the Archives of Dermatology.