Human Nature: Science, Technology, and Life.

Obama’s Gray Hair

Are the burdens of the presidency graying Barack Obama? Are his gray hairs a sign of life-shortening stress?

Today's New York Times front page makes it sound that way:

For a guy who prides himself on projecting a stress-free demeanor, the changes above his temples are speckled evidence that perhaps the psychological and physical strains of the job—never mind the long process of winning it—are in fact taking something of a toll. (Experts say stress can contribute to whitening locks.) ...

But with the economy struggling, two wars raging and countless other pressures facing him, the president is very likely to see additional signs of wear and tear in the mirror each morning. "Presidents age two years for every year that they're in office," said Dr. Michael F. Roizen, co-founder of RealAge, a Web site that tells you how much older your body really is because of all that smoking and drinking you have been doing. ... Rapidly lightening locks are just one sign that the job is getting to America's presidents.

The front page of today's Washington Post Style section agrees:

Are times so stressful—a plummeting economy and two wars—that our young president is going grayer a mere six weeks into the job? ... With each debate, after every primary fight, it seems Barack Obama's tightly clipped hair became just a dash saltier. ... And it's an article of faith, backed by photographic evidence, that the Oval Office ages the men in it. Look no further than George W. Bush and Bill Clinton.

It's natural to look at the president's gray hair and take it as a sign of job stress. But guess what's even more natural? Gray hair. The Times' headline—"For Young President, Flecks of Gray"—implies that Obama is graying prematurely. Not true. According to a scholarly review published three years ago in the Journal of Investigative Dermatology, "Age of onset of graying also appears to be hereditary, developing usually in late fourth decade. Thus, the average age for Whites is mid-30s, for Orientals late-30s, and for Africans mid-40s, such that by 50 years of age, 50% of people have 50% gray hair."

Obama is 47. As the Times and Post photographs show, he's only marginally gray. He's right on schedule.

Is his gray hair a sign of premature aging, "wear and tear" and "taking a toll," as the newspaper stories imply? Sorry. Evidence published in Medical Hypotheses suggests otherwise:

An office and autopsy study was performed to see if early graying was associated with increased morbidity, earlier age at death, and specific cause of death. 195 consecutive office patients over the age of 40 were studied to see if premature graying of scalp hair (50% or more gray before age 50) was associated with increased incidence of disease before age 50 ...For fathers, mean age at death if prematurely gray was 68.27 years; if not prematurely gray, 66.03 years ... For mothers, the values were 70.55 years and 70.37 years respectively ... 874 autopsy patients dying over a 23-year period (1966-1989) were studied to see if the median age at death (of patients 50% or more gray) differed for any of the six categories of disease (myocardial infarction, congestive heart failure, cancer, stroke, pneumonia/bronchitis, or cirrhosis of the liver/GI problems) when compared to the entire autopsy sample of 19 categories of disease ... This dual office and autopsy study provides no evidence to support the contention that early gray hair is a risk factor.

The study, published in 1991, is getting a bit old. But then, aren't we all? Bill Clinton was 46 when he became president. George W. Bush was 53. That's perfectly consistent with the 50-50-50 rule (50 percent of people being 50 percent gray by age 50). There's nothing premature about their grayness—or Obama's. Being president may be bad for your health. But your gray hair tells us nothing.

Age, Wisdom, and Driving

Here's the theory: Old people are bad drivers. And we're living longer, so there are more old people on the road, so they're causing more accidents. And they're already fragile, so they're killing more people, including themselves. Right?

Wrong. According to the latest data from the Insurance Institute for Highway Safety (flagged by Tara Parker-Pope of the New York Times), it's true that "older people now hang onto their licenses longer, drive more miles, and make up a bigger proportion of the population than in past years as baby boomers age." It's also true that "per mile traveled, crash rates and fatal crash rates increase starting at age 70 and rise markedly after 80," possibly because "physical, cognitive, and visual declines associated with aging may lead to increased crash risk."

That's what makes the bottom-line findings so surprising:

Despite growing numbers on the road, fewer older drivers died in crashes and fewer were involved in fatal collisions during 1997-2006 than in years past. ... Crash deaths among drivers 70 and older fell 21 percent during the period, reversing an upward trend, even as the population of people 70 and older rose 10 percent. Compared with drivers ages 35-54, older drivers experienced much bigger declines in fatal crash involvements.

The institute's chief of research adds: "No matter how we looked at the fatal crash data for this age group—whether by miles driven, licensed drivers, or population—the fatal crash involvement rates for drivers 70 and older declined, and did so at a faster pace than the rates for drivers 35-54 years old."

So what gives? "Reasons for the fatality declines aren't clear, but another new Institute study indicates that older adults increasingly self-limit driving as they age and develop physical and cognitive impairments," says the IIHS. In that study,

The oldest drivers were more likely to say they restricted their own driving. Drivers 80 and older were more than twice as likely as 65-69 year-olds to self-limit driving by doing such things as avoiding night driving, making fewer trips, traveling shorter distances, and avoiding interstates and driving in ice or snow. The percentage of drivers who said they limit their driving increased with each added degree of impairment. Drivers cited memory and medical impairments more often than vision or mobility ones.

In other words, as we age, self-knowledge and self-regulation compensate for our loss of abilities. As Farhad Manjoo reported four months ago in Slate,

Statistics on current road deaths show that people over the age of 65 are only 16 percent more likely to cause accidents than are people aged 25 to 64. Drivers under 25, meanwhile, are the most dangerous people on the road—they're 188 percent more likely to cause crashes than middle-aged adults.

Aging is a tragic but beautiful process: As we decay in some ways, we grow in others. We become less able to control the world but more able to control ourselves. As IIHS points out, our decline isn't just physical; it's mental, too. Yet we understand ourselves better than ever. Even as our vision deteriorates, we become more clear-eyed about our own limits. And even as our memory degrades, we develop a more important kind of knowledge: We know what we don't know.

Not everyone grows this way. To the extent that self-regulation has reduced fatal crash rates among aging drivers, the implication is that old people can be made more aware of their limits and can adjust accordingly. If you're aging, the lesson is to monitor and govern your driving. And if you're young, the lesson is to cultivate what old people have—self-knowledge and self-control—while your mind and body are still at full strength.

Cyborg Seniors

If you get the Human Nature RSS feed but don't check the Slate home page, you may have missed an article worth reading: How seniors became cyborgs. It's about the mechanical and electronic components we've been putting into old people to replace failing body parts. It's part of our "Geezers" issue. Take a look.

No Chubby For Old Men

 If you're looking for interesting bathroom reading, allow me to recommend Urology. The July issue is chock full of page-turners: "Robotic Prostatectomy," "Scrotal Mass with Bladder Outlet Obstruction," "Histologic Comparison of Pubovaginal Sling Graft Materials," "Multi-Drug-Resistant Bacteremia After Transrectal Ultrasound Guided Prostate Biopsies," and my favorite, "Modern Management of Adult-Acquired Buried Penis" (it's "a result of obesity" - don't ask).

Seriously, though, I want to talk about an article in the July issue. It's called, "Does ‘Normal' Aging Imply Urinary, Bowel, and Erectile Dysfunction?" Here are key excerpts from the abstract:

We assessed if urinary, bowel, and sexual dysfunction and associated bother were part of the "normal" aging process in the general male Dutch population. ... Three thousand eight hundred ten (3810) men responded (81%), mean age 67 years, range 58 to 78. ... Bowel dysfunction and bother were not related to age. Erectile dysfunction was reported by 19%, ranging from 12% in the youngest to 26% in the oldest group ...

Conclusions: Urinary and bowel dysfunction were not part of the "normal" aging process. Erectile dysfunction was significantly more prevalent in older men.

And here's the headline on the Reuters write-up: "Erectile dysfunction may be ‘normal' with age."

The curious thing here is the word normal. It's being used in this context to mean age-related. Most men in the sample didn't have erectile dysfunction. But because ED's frequency increases with age, and because we think of aging as a universal process accompanied by physical decline, ED seems normal.

Since "urinary and bowel dysfunction were not part of the ‘normal' aging process," the authors conclude, they "may well be related to prior treatment" in men who have been treated for prostate cancer. This appears to make them logical targets for prevention or remedy. Does the opposite implication follow for ED? Does its "normality" make it a less compelling target?

There are many plausible ways to think about normality and health. Age-dependence is one of them. To me, the authors' framework makes sense: Medicine should focus first on maladies that strike some people unusually early in life. Maladies that accumulate with age are less unfair. They're also less tractable, since they're more biologically inherent.

ED, however, is a confounding example because it's in the process of being transformed from a "normal" to a commonly treated condition. Bob Dole made his famous ad for Viagra  in 1999, when he was 76. In the last decade, 35 million men have used Viagra. Millions more have taken similar drugs such as Cialis or Levitra. Modern man has set out to conquer the ancient loss of manhood.