Use the arrows above to age president-elect Barack Obama

“When I started this campaign, everybody called me a young man—they’re not calling me that anymore,” Barack Obama remarked in August on the campaign trail. “I’m getting gray hair—running for president will age you quick.”

If Obama thought campaigning for president had grayed his mane at warp speed, just wait till he starts working in the Oval Office. “The reality of it is that he will probably age 20 years in the first term,” says Deirdre Hogan, of the Toronto-based Aprilage Development Inc., whose aging software has been used in hospitals and science museums for almost a decade.

Cases in point: Bill Clinton and George W. Bush. On their respective inaugurations, Presidents 42 and 43 were youthful-looking baby boomers, nary a gray hair or wrinkle to be seen. Two terms later, both Clinton and Bush looked drastically grayer and more careworn. You can tell by their before-and-after pictures, seen here.

With that in mind, we asked Aprilage to predict how the 47-year-old Obama might look after four and eight years in the White House. Using its database of 7,000 photographs of people of diverse ages, ethnicities, and lifestyle habits, Aprilage identified images of men physically comparable to Obama and then applied an average of these attributes to a photograph of the president-elect. The pictures, as you can see, speak for themselves.

So, what is it about the U.S. presidency that seems to age its occupant in dog years? “His job is so much harder,” says Dr. Kevin R. Lough?lin, a presidential health expert. “The whole world rests on his decisions.”

Medically, there’s a relationship between stress and aging, says Dr. Simon S. Yoo, assistant professor in the Department of Dermatology at Northwestern’s School of Medicine. Long-term stress can damage the melanocytes, pigment-producing cells in the hair and skin, causing age spots and gray hair. Moreover, chronic stress elevates the cortisol level in the body, which pulls the blood away from the skin, making it look more sallow.

While there’s a link between stress and premature aging, there isn’t necessarily a proven correlation between the American presidency and accelerated aging. It may just be in the eye of the beholder. Says Yoo: “Presidents are constantly in the public eye, so you notice it more.”

Multimedia: Steve Peterson, Photography: (clinton 1992) ap photo/ron haviv/VII, (clinton 2000) ap photo/michel euler, (bush 2000) ap photo/robert f. bukaty, (bush 2008) ap photo/lawrence jackson, (obama at 47) ap photo/mannie garcia/file, (obama age 48-59) aprilage development inc.