The effects of aging

Photo: Michelle Mauser, University Hospital Medical Group

Nature vs. Nurture: The Beauty Edition
A panel of four judges analyzed photographs of 186 identical twins and estimated their ages. Since the duos share exactly the same genetic material, differences in how old they appear can be attributed to their individual behaviors and experiences, says the study's lead author, Bahman Guyuron, MD, chair of the department of plastic surgery at University Hospitals Case Western Reserve University in Cleveland. Here's what the study found .
A scale

For twins under the age of 40, a body mass index (BMI) difference of four points made the thinner twin look, on average, up to three years younger. Over 40, however, the same disparity in weight made the heavier twin look up to three years younger. And over 55, that effect was even more pronounced.

Divorced twins looked older (by almost two years) than those who were still married. Incidentally, they also looked older than their sisters who had never married or were widowed.
Prescription drugs

Current and past use of antidepressants was linked to appearing up to seven years older. This might be because the drugs relax the body (including facial muscles), potentially making the face look droopier. Or, Guyuron theorizes, depression may compromise the production of certain hormones, like human growth hormone, that contribute to healthy, plump skin.

Twins who had undergone hormone replacement therapy looked more youthful than those who had not. By the age of 70, a twin who had undergone hormone replacement therapy for at least 16 years looked four years younger.

No surprises here: A twin who smoked looked much older than one who didn't (about two and a half years older for every ten years of smoking). Increased sun exposure or lack of sunscreen use were also associated with more pronounced signs of aging, like lax skin and discoloration.

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