(President Barack Obama with his daughter Sasha at the 2011 National Christmas Tree lighting; Credit: Getty Images)
Speculation has long existed that U.S. presidents age at twice the normal rate, with many tabloid stories fixating on President Obama's every new wrinkle, gray hair and weight change. But a new study finds just the opposite: Most U.S. presidents live longer than predicted for men of their same age and era.
The study, published in JAMA, the Journal of the American Medical Association, came to fruition when University of Illinois at Chicago demographer S. Jay Olshansky, noticed a flurry of news reports in the summer of 2011, when President Obama celebrated the big 5-0 birthday. The president still looks in shape to me, but a lot of reporters then commented that he was aging quickly. Some have even done then-and-now photo comparisons to prove their point.
"In the world of biology we know that you can't actually measure the aging of an individual," Olshansky, a professor of epidemiology at the UIC School of Public Health, was quoted as saying in a press release. "There isn't any single test to actually measure how long you've aged from point A to point B, nor is it possible to predict specifically how long an individual will live."
Using the assumption that presidents age at twice the normal rate, Olshansky calculated how long U.S. presidents would have been expected to live based on their age and the year they were inaugurated, and compared it to how long they actually lived.
Aging at twice the normal rate was estimated by removing two days of life for every day in office. For example, a 4-year term led to a reduction in estimated remaining lifespan of 8 years.
Olshansky determined that 23 of the 34 U.S. presidents who died from natural causes lived longer, and in many instances significantly longer, than predicted. Their average age at inauguration was 55.1 years.
Four presidents who were assassinated were removed from the analysis.
Consider that the average lifespan of the first eight presidents was 79.8 years, during a time when life expectancy at birth for men was less than 40.
"This is about how long females born in the U.S. today live," Olshansky said.
The study also found that living ex-presidents have either already exceeded their predicted longevity at the time of their inauguration, or are likely to do so.
"We know that socioeconomic status has an extremely powerful effect on longevity now," Olshansky said, "and it was likely to have been a factor in the past." All but 10 U.S. presidents were college educated. All were wealthy, and all had access to health care.
"We don't die from gray hair and wrinkled skin," concluded Olshansky. "What we're seeing in President Obama is really not inconsistent with what we see for any other man his age in the U.S. or elsewhere."