A new study of twins hints at the ways smoking makes you look older than you really are.

In what is perhaps the best detail of the study, researchers used the annual Twins Days Festival in Twinsburg, Ohio (the "Largest Annual Gathering of Twins in the World!") to round up the 79 identical pairs they include in the report. A panel of three plastic surgery residents compared the faces of the twins, one of which had been smoking for at least five years longer than the other.

They identified a few major areas of accelerated aging in the faces of the smoking twins: The smokers' upper eyelids drooped while the lower lids sagged, and they had more wrinkles around the mouth. The smokers were also more likely to have jowls, according to the study, published in the journal Plastic and Reconstructive Surgery.

Smoking reduces oxygen to the skin, which also decreases blood circulation, and that can result in weathered, wrinkled, older-looking skin, explains Dr. Bahman Guyuron, a plastic surgeon in Cleveland, Ohio, and the lead author of the study.

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