A human longevity expert assessed the longstanding theory that the stresses of the job make American presidents age more quickly. When Barack Obama celebrated his 50th birthday in August 2012, journalists and experts noted that the president was showing more wear and tear—mostly in the form of wrinkles and gray hair—than when he took office in January 2009. Their observations sparked a flurry of news reports referencing the longstanding theory that U.S. president grow older more quickly than their contemporaries, perhaps due to the stresses of the job.

And though some dermatologists maintain that Obama was the latest victim of an expedited aging process in which presidents appear to age faster because of the stress of the office, others say that it's more attributable to natural aging than stress. And even so privileged people, including presidents, live longer lives. The youngest to become president after having been elected was John F. Kennedy, at the age of 43 years, 236 days on Inauguration Day. The oldest person to assume the presidency was Donald Trump, at the age of 70 years, 220 days on Inauguration Day. Of all presidents in history who wasn't assassinated went on to live dozens of years beyond the age they were inaugurated. The stress of the office took its toll on all in a matter of eight years. Going in at 73 or 78 will be a new frontier of presidential aging but if it is not the body of aging skin and grey hair taking its toll, is the mind a few steps behind. Ronald Wilson Reagan was 69 years, 11 months, 11 days when he took office although he aged gracefully his mind didn't after 6 years in office.