The effects of smoking on facial ageing are most apparent in the lower two-thirds of the face, researchers found. (Agencies)
In the study, twins who smoke showed more premature facial ageing, compared to their nonsmoking identical twins.
The research found significant differences in facial ageing between twins with as little as five years' difference in smoking history, according to Dr Bahman Guyuron, Professo and Chairman, Department of Plastic Surgery, University Hospital Case Medical and Case School of Medicine, Cleveland.
In an annual Twin Days Festival, held in Twinsburg, Ohio, the researchers identified pairs of identical twins who differed by smoking history.
In each pair, either one twin smoked and the other did not, or one twin smoked at least five years longer. Fifty-seven of the 79 twin pairs studied were women; the average age 48 years.
A professional photographer took standardized, close-up photographs of each twin's face. The twins also completed questionnaires regarding their medical and lifestyle histories.
Without knowledge of the twins' smoking history, plastic surgeons analyzed the twins' facial features, including grading of wrinkles and age-related facial features.
Scores on several measures of facial ageing were significantly worse for the smokers. The smokers had more sagging of the upper eyelids, as well as more bags of the lower eyelids and under the eyes.
Twins who smoked also had higher scores for facial wrinkles, including more pronounced nasolabial folds (lines between the nose and mouth), wrinkling of the upper and lower lips and sagging jowls.
Most of the smoking-related differences affected the middle and lower thirds of the face. There were fewer differences in ageing of the upper face, such as forehead lines or "crow's feet" around the eyes.
"It is noteworthy that even among sets of twins where both are smokers, a difference in five years or more of smoking duration can cause visibly identifiable changes in facial ageing," researchers said.
The study will appear in Plastic and Reconstructive Surgery, the official medical journal of the American Society of Plastic Surgeons (ASPS).
The effects of smoking on facial ageing are most apparent in the lower two-thirds of the face, researchers found.