Background: The purpose of this study was to identify the environmental factors that contribute to facial aging in [discordant] identical twins.
Method: During the Twins Day Festival in Twinsburg, Ohio, 186 pairs of identical twins completed a comprehensive questionnaire, and digital images were obtained. A panel reviewed the images independently and recorded the differences in the perceived twins’ ages and their facial features. The perceived age differences were then correlated with multiple factors.
Results:
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4-point higher body mass index was associated with an older appearance in twins younger than age 40 but resulted in a younger appearance after age 40 (p = 0.0001). 8-point higher body mass index was associated with an older appearance in twins younger than age 55 but was associated with a younger appearance after age 55 (p = 0.0001).
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The longer the twins smoked, the older they appeared (p < 0.0001).
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Increased sun exposure was associated with an older appearance and accelerated with age (p = 0.015), as was a history of outdoor activities and lack of sunscreen use.
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Twins who used hormone replacement had a younger appearance (p = 0.002).
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Facial rhytids were more evident in twins with a history of skin cancer (p = 0.05) and in those who smoked (p = 0.005).
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Dark and patchy skin discoloration was less prevalent in twins with a higher body mass index (p = 0.01) and more common in twins with a history of smoking (p = 0.005) and those with sun exposure (p = 0.005).
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Hair quantity was better with a higher body mass index (p = 0.01) although worse with a history of skin cancer (p = 0.005) and better with the use of hormones (p = 0.05).
Conclusion: This study offers strong statistical evidence to support the role of some known factors that govern facial aging.
…Marital Status: Women who had been divorced looked older than their married or single counterpart (p = 0.004). There were no differences found with increasing number of divorces. The twin who was divorced appeared about 1.7 years older than the twin who was not divorced. The twin who was a widow or widower appeared about 2 years younger than the twin who was not.
Use of Antidepressants: The current or past usage of antidepressants was associated with a statistically-significantly older appearance when compared with the twin with no history of antidepressant use (p < 0.05)…The increased perceived age of female twins who used antidepressants was also seen. This is also corroborated by et al 2006, who found that depression was borderline statistically-significant with facial aging.
Avoidance of alcohol was associated with a younger appearance (p = 0.0002).
The longer the twin smoked (beyond 5 years), the older she appeared (p = 0.005). Each 10 years of smoking difference led to a 2-year increase in perceived age.
