Of the 1,800 sets of twins that journeyed to Twinsburg, Ohio last year for the annual Twins Days Festival, 65 pairs of both identical and fraternal twins were recruited by a team of dermatologists from Case Western Reserve School of Medicine for a study about the impact of sun exposure, smoking, alcohol consumption and weight on the skin’s aging process. (Twin studies are appealing as they allow researchers to control for “genetic susceptibility” when assessing the impact of external factors.) Confirming previous research—and challenging studies that had suggested little impact of smoking on skin wrinkling—researchers found that all of these external factors, with the exception of alcohol consumption, contributed to skin damage.
In the study, published in the December issue of the Archives of Dermatology, researchers specifically measured “photodamage,” which they explain is the impact of external factors such as sun exposure. (Non-genetic factors, the authors point out, account for roughly 40% of the appearance of aged skin.) Additionally, photodamage is distinct from the normal aging process, indicated by fine wrinkles and skin growths, in that it includes a range of symptoms caused by sun damage and other external factors—rough, larger wrinkles, spottiness in pigmentation, and swollen blood vessels in the face.
Study participants, who ranged in age from 18 to 77, were asked to fill out questionnaires addressing weight, smoking habits, drinking, and regular sun exposure. Medical professionals monitored the process to help ensure accuracy, and also underwent a dermatologic assessment of skin damage. Unsurprisingly, older study participants were more likely to have higher levels of photodamage, as were twins with a family history of skin cancer. Additionally, smoking, being overweight, regular sun exposure and infrequent use of sunscreen were all associated with higher levels of skin damage, whereas regular alcohol consumption was not. As researchers did not specify type of alcohol in the survey questions, it’s difficult to draw more specific conclusions, but they speculate that the presence of antioxidants such such as resveratrol in red wine, for example, might explain the potential benefits of alcohol consumption on the skin’s aging process.