[tt] WP: Aging Gracefully: It's a Real Workout

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Aging Gracefully: It's a Real Workout
http://www.washingtonpost.com/wp-dyn/content/article/2008/08/15/AR2008081502980_pf.html

By Jonah Lehrer
Sunday, August 17, 2008; B01

The most depressing thing about getting older is that it can't be
stopped. Or so we've been told. The aging process seems to be one of
inevitable decline, the withering away of both body and mind. No
matter how much we rage against the dying of the light, we're still
going to forget where we put our car keys.

But is our fate really so fixed? Is the march of time always so
cruel? All signs point to . . . not really. Consider Dara Torres,
the 41-year-old U.S. swimmer, who is nine years older than her
closest-in-age teammate in Beijing. Although now competing in her
fifth Olympics, Torres is swimming faster than ever before. Or what
about Madonna? The pop star may have turned 50 yesterday, but the
synth beat goes on. She's currently preparing for her "Sticky and
Sweet" tour, where diehard fans will pay up to $350 to see the
former Material Girl perform, clad for part of the time in what the
designer overseeing her look described as "Gangster Pimp"-inspired
fashion.

And then there's the presidential campaign, which has put age and
generational differences front and center. John McCain, at 71, is 
attempting to become the oldest first-term president in American
history. His run, along with the unretirement of 38-year-old NFL
quarterback Brett Favre, is part of this recent parade of public age
defiance. This doesn't mean, of course, that weekend warriors
pushing 40 now think that their pro-football dreams still have a
glimmer of hope, or that 50-somethings are demanding, en masse,
higher age cutoffs on "American Idol." But it does show, on a broad
variety of prominent stages, that more and more, people aren't
clinging to empty platitudes about age being just a number. Instead,
they're ignoring age as a limiting factor entirely. Time, it turns
out, is something you can bargain with.

As a 27-year old science writer who still gets carded at bars, I
often find discussions of the aging process pleasantly abstract. I'm
more likely to use Clearasil than anti-wrinkle cream. But the
spectacle of Torres's competing and McCain's campaigning has
rekindled an important scientific debate about the inevitability of
the aging process and what even young and middle-aged people can do
to blunt the adverse effects of time.

New research demonstrates that Torres, Madonna and McCain's mother,
Roberta -- who is still campaigning for her son at the age of 96 --
aren't rare outliers, but rather examples of a somewhat common
phenomenon. According to scientists, it's entirely possible to grow
significantly older without getting much slower -- as long as we're
willing to put in the work. The elixir of youth, it turns out, is an
old-fashioned cocktail: blood, sweat and tears.

This scientific research arrives just as the graying of the baby
boomers is leading to an explosive growth in medical treatments that
promise a perpetual adolescence. With its offerings of dietary
supplements and caloric-restriction diets, face creams infused with
fetal stem cells and injections of Botox, the anti-aging industry
has managed to turn an inescapable biological process into a
lucrative source of anxiety. What the latest science suggests,
however, is that the best anti-aging treatment isn't something you
apply to your skin or buy in a bottle: It's what you already have in
your head. The bad news, of course, is that the same research shows
that the passage of time is not an equal opportunity eroder.

Last year, a large study led by researchers at Harvard University
compared the brains of young adults and senior citizens. As
expected, the scientists found consistent differences between the
two groups. The most significant occurred in a brain system known as
the "default network," which is active when people turn their attention 
inward, as when they're trying to remember a name. The
default network is defined by a series of pathways between the front
of the brain -- this includes areas of the prefrontal cortex -- and
the "back" of the brain, such as the cingulate cortex.

Under normal circumstances, the default network ensures that these
two brain areas work in perfect sync. "When the front of the brain
fires, you want to see the back of the brain fire right back," says
Jessica Andrews-Hanna, the study's lead author. "Unfortunately, this
connection seems to weaken with age, so that older people can end up
with a rather disconnected brain." Andrews-Hanna suggests that
deficits in the default network might be responsible for many of the
classic symptoms of old age, such as an inability to focus and
problems with memory retrieval.

So far, so depressing. The aging process is a biological wrecking
crew. But buried in all the bad news are some optimistic data. It
turned out that nearly half of the older subjects exhibited brain
activity that appeared indistinguishable from that of the young
adults: Their default system was nearly as synchronized as those of
people in their 20s. Furthermore, these differences in brain
activity were correlated with performance on a battery of tests that
measured short-term memory, abstract reasoning powers and processing
speed. "There really was tremendous individual variation,"
Andrews-Hanna says, "and this variation was evident both in the
brain and in observed behavior."

The question, of course, is what causes this variation. How do some
people manage to maintain such a spry cortex? Some scientists argue
that the secret to thinking like a young person is cognitive
exercise. "The brain is a learning machine, and like all machines it
needs to be continually maintained," says Michael Merzenich, a
professor emeritus at the University of California at San Francisco.
"If you stop exercising the brain -- and this is what often happens
during retirement -- then you shouldn't be surprised when it starts
to die off."

Merzenich has developed a software program, Posit Science Brain
Fitness, that helped reverse the cognitive effects of aging in 93
percent of elderly subjects, according to a 2006 study. After a few
months of intensive training, the brains of 75-year-olds had the
memory function of people decades younger, at least when tested in a
lab. Just as Dara Torres maintains her edge through a relentless
practice schedule -- in addition to hours of swimming and extensive
weight-lifting sessions, she also reportedly stretches for several
hours multiple times a week -- Merzenich argues that the aging brain
requires rigorous workouts to stay in shape. There are no shortcuts.
Even people blessed with ideal genetics -- those lucky souls at low
risk for wrinkles and memory loss -- still need to exercise the mind
to preserve their mental vigor.

But the mind does have one crucial advantage over the body: It can
rewire itself as it tries to cope with the challenges of getting
older. According to Denise Park, a neuroscientist in the Productive
Aging Laboratory at the University of Texas at Dallas, the
inevitable atrophy caused by the aging process means that older
brains must continually find new ways to perform the same mental
tasks. The cortex deals with cell death by re-directing its traffic,
becoming more reliant on those neural pathways that remain viable.

Although it's still unclear where such mental flexibility comes
from, several studies suggest that it's largely an ancillary benefit
of "sustained cognitive engagement," or thinking intensely on a
regular basis. Not only does an active mind have more cortical
matter to lose -- scientists refer to this as "cognitive reserve,"
since the extra tissue serves as a buffer against cell death -- but
it also seems better able to adjust its activity in response to the
insults of age. "The brain operates on a use-it-or-lose-it
principle," says Merzenich. "And the ability to cope with change
seems to really be something you either use or lose."

What this suggests is that successful aging has little to do with
stopping the aging process, because that can't be done. Our flesh is
mortal; there is no fountain of youth. Dara Torres herself talks
about how much longer it takes her body to recover at the age of 41,
which is one reason she chose to race individually only in the
50-meter freestyle at the Beijing Olympics. Nevertheless, as she
demonstrates, these anatomical changes don't need to become
handicaps. The brain is a flexible machine: If we put in the effort
-- and it takes lots of effort -- our cells will find a way to stay
fit. Nobody ever said aging gracefully was easy.

jonah.lehrer at gmail.com

Jonah Lehrer is an editor at large at Seed magazine and the author
of "Proust Was a Neuroscientist."