[MUSIC] What am I thinking about? Mortgage, debt,
money pouring out... And I felt a lump--I know cancer when I
feel it. Where is she? What is she up to? Never calling, never
saying a word... >> Stress. It is everyone's inferno, bedeviling our
minds, igniting our nights, upending our equilibrium--but it hasn't
always been so. [MUSIC] Once, its purpose was to save us. >> If
you're a normal mammal, what stress is about is three minutes of
screaming terror on the savanna, after which it's either over with or you're over
with. >> But everything changed. What once helped us survive has now become
the scourge of our lives. >> And I just burst into tears, and wept, and
wept. >> Today, scientific discoveries, in the field...
[PUFF SOUND]. >> Got him. Ooop. >> And in the lab, prove that stress
is not a state of mind, but something measurable, and dangerous. >>
This is not an abstract concept. It's not something that maybe someday you
should do something about. You need to attend to it today. >> In some
of the most unexpected places, scientists are revealing just how lethal
stress can be. >> Chronic stress could do something as unsubtle and grotesque as
kill some of your brain cells. >> The impact of stress can be found deep
within us, shrinking our brains, adding fat to our bellies, even unraveling
our chromosomes. >> This is real, this is not just somebody
whining. [ANIMAL DISTRESS SOUND]. >> Stress--savior, tyrant, plague--its
portrait revealed. [MUSIC] >> This program was made possible by
contributions to your PBS station from viewers like you.
Thank you. [MUSIC] >> All of us have a personal relationship
with stress, but few of us know how it operates within us.
Or understand how the onslaught of the modern
world can stress us to the point of death. [MUSIC] Fewer still know what we can do about it. [MUSIC] But over the last three decades, Stanford
University neurobiologist Robert Sapolsky has been advancing our understanding of
stress--how it impacts our bodies, and how our social standing can make us more
or less susceptible. >> Is the aggregate bad news and more... >> Most of the time,
you can find him teaching and researching in the high-achieving,
high-stressed world of brain science. >> The paper is this huge contrast
between... >> But that's only part of his story. For a few
weeks every year or so, Sapolsky shifts his lab to a place
more than 9,000 miles away on the plains of the Masai Mara Reserve, in
Kenya, East Africa. [MUSIC] Robert Sapolsky first came to Africa over
30 years ago on a hunch. He suspected he could find out more about
human stress and disease by looking at non-humans, and he
knew just the non-humans. [MUSIC] >> You live in a place like this, you're a
baboon, and you only have to spend about three hours a
day getting your calories. And if you only have to work three hours a
day, you got nine hours of free time every day to devote to making
somebody else just miserable. [SCREECH SOUNDS] They are not being stressed by
lions chasing them all the time, they're being stressed by each other. They
are being stressed by social and psychological tumult invented by their own
species. They are a perfect model for Westernized
stress-related disease. >> To determine just what toll stress was
taking on their bodies, Sapolsky wanted to look inside these wild baboons at the
cellular level for the very first time. To do this, he would have to take their
blood in the most unassuming way. [MUSIC] >> Basically, what you're trying to do is
anesthetize a baboon, without him knowing it's coming. Because you don't want to
have any of this anticipatory stress, so you can't just, you know, get in your jeep
and chase the baboon up and down the field for three hours, and, finally, when he's
winded, dart him with an anesthetic. [MUSIC] Now, the big advantages of a blowgun are
that it's pretty much silent, and hasn't a whole lot in a way of moving parts, but
the big drawback is doesn't go very far. [MUSIC] So what you spend just a bizarre amount of
time doing is trying to figure out how to look nonchalant around a baboon. [PUFF
SOUND] Got him. Time? Okay, he is wobbling now. Whoop,
there he goes. >> From each baboon blood sample, Robert
measured levels of hormones central to the stress response. >> Well, to make
sense of what's happening in your body, you've got these two hormones that are the
workhorses, the whole stress response. One of them, we all know,
adrenaline--American version, epinephrine. The other is a less known hormone called
glucocorticoids, comes out of the adrenal gland along with adrenaline. And these are
the two backbones of the stress response. [ZEBRA BARKS]. >> That stress response and those two hormones are critical to our
survival. [HOOF SOUNDS]. >> Because what stress is about is
somebody is very intent on eating you, or you are very intent on eating somebody,
and there's an immediate crisis going on. >> When you run for your life, basics are
all that matter. Lungs work overtime to pump mammoth quantities of oxygen into the
bloodstream. The heart races to pump that oxygen throughout the body so muscles
respond instantly. [SPLASHING SOUNDS]. >> You need your blood pressure up to
deliver that energy. You need to turn off anything that's not
essential--growth, reproduction, you know, you're running for your life, this is no
time to ovulate, tissue repair, all that sort of thing--do it later, if there
is a later. >> When the zebra escapes, its stress response shuts down. But human
beings can't seem to find their off switch. >> We turn on
the exact same stress response for purely psychological states---thinking
about the ozone layer, the taxes coming up, mortality, 30-year mortgages--we turn
on the same stress response. And the key difference there is, we're not
doing it for a real physiological reason, and we're doing it nonstop. >> By not
turning off the stress response when reacting to
life's traffic jams, we wallow in a corrosive bath of hormones. Even though
it's not life or death, we hyperventilate, our hearts pound,
muscles tense. >> Ironically, after a while, the stress response is more
damaging than the stressor itself, because the stressor is some psychological
nonsense that you're falling for. No zebra on Earth, running for its life, would understand why...fear of speaking in
public would cause you to secrete the same hormones that it's doing at that
point to save its life. >> Stress is the body's way of rising to a
challenge, whether the challenge is life-threatening, trivial, or fun. >> You
get the right amount of stress, and we call it stimulation. The goal in
life isn't to get rid of stress--the goal in life is to have the right type of
stress, because when it's the right type, we love it.
[ROARING SOUND] We jump out of our seats to experience it,
we pay good money to get stressed that way. It tends to be a moderate stressor, where
you've got a stressor that's transient. It's not for nothing roller coaster
rides are not three weeks long.
And most of all, what they're about is, you relinquish a little bit of control
in a setting that overall feels safe. >> 50 and 25. >> Anticipating the long
reach of stress is a recent idea, for when Robert was Rachel's age, scientists
believed stress was the cause of only one major problem.
[THROBBING SOUND]. >> This is a picture of a major American
personnel problem--an ugly sore that doctors call a peptic ulcer, eating
away at the wall of a man's stomach. [MUSIC] >> Those stomach pains that you talk
about, the gnawing, the burning, those are obvious symptoms of gastric ulcer. >>
Thirty years ago, what's the disease that comes to everybody's mind when you mention
stress--it's ulcers, stress and ulcers, stress and ulcers. And this was the first
stress-related disease discovered, in fact, 70 years ago. >> What I want you
to do is to work on your attitude. >> My attitude? >> That's right. Ulcers
breed on the wrong kind of feeling. You've got to be honest with yourself
about the way you feel about it. >> Finding a new doctor sounds like a
better answer to me. >> The connection between stress and ulcers was mainstream
medical gospel until the early 1980s. Then, Australian researchers identified a
bacteria as the major cause of ulcers. >> And this overthrew the entire field,
this was, it's got nothing to do with stress, it's a
bacterial disorder. And I'm willing to bet half the gastroenterologists on Earth,
when they heard about this, went out and celebrated that night. This was, like, the
greatest news--never again were they going to have to sit down their patients, and
make eye contact, and ask them how is it going, so, anything
stressful--it's got nothing to do with stress, it's a bacterial disorder.
>> So no longer would the solution be stress management, now it could be
something as simple as a pill. It was a major breakthrough--stress didn't
cause ulcers. Case closed. [MUSIC] But a few years later, the research took a
new twist. Scientists discovered that this
ulcer-causing bacteria wasn't unique--in fact, as much as two thirds of
the world's population has it. [MUSIC] So why do only a fraction of these people
develop ulcers? Research revealed that when stressed, the body begins shutting
down all non-essential systems, including the immune system. And it became clear
that, if you shut down the immune system, stomach bacteria can run amuck. >> Because
what the stress does, is wipe out the ability of your body to
begin to repair your stomach walls when they start rotting away from his
bacteria. [SOUND]. >> So stress can cause ulcers by disrupting our
body's ability to heal itself. [MUSIC] If stress can undermine the immune system,
what other havoc can it wreak? One answer comes from a colony of captive
macaque monkeys near Winston-Salem, North Carolina. >> People think of stress
as something that keeps them up at night, or something that makes them yell at their
kids. But, you ask me, what is stress, I say, Look at it--it's this huge plaque
in this artery, that's what stress is. >> For two decades, Dr. Carol Shively has
been studying the arteries of macaques. [MUSIC] Like baboons and British civil servants,
these primates organize themselves into distinctly hierarchical groups, and
subject one another to social stress. [SCREECH SOUND] Stress hormones can
trigger an intense negative cardiovascular response, a pounding heart and increased
blood pressure. So, if stress follows rank, would the
cardiovascular system of a high-ranking macaque, call him a primate
CEO, be different from his subordinate? [MUSIC] When Shively looked at the arteries of a
dominant monkey, one with little history of stress, its
arteries were clean. But a subordinate monkey's arteries told a
grim tale. >> A subordinate artery has lots more atherosclerosis built up
inside it than a dominant artery does. >> Stress, and the resulting flood of
hormones, had increased blood pressure, damaging artery walls, making them
repositories for plaque. >> So now, when you feel threatened, your
arteries don't expand, and your heart muscle doesn't get more blood,
and that can lead to a heart attack. This is not an abstract concept, it's not
something that maybe someday you should do something about, you need to attend to it
today, because it's affecting the way your body functions. And a stress today
will affect your health tomorrow and for years to come. >> Social and psychological
stress, whether macaque, human, or baboon, can
clog our arteries, restrict blood flow, jeopardize the health of our heart--and
that's just the beginning of stress's deadly curse. Robert's early research
demonstrated that stress can work on us in an even more
frightening way. >> Well, back when I was starting in this
business, what I wound up focusing on was what seemed an utterly
implausible idea at the time, which was chronic stress and chronic
exposure to glucocorticoids could do something as unsubtle and grotesque as
kill some of your brain cells. >> As a PhD candidate at Rockefeller
University in the early '80s, Sapolsky collaborated with his mentor, Dr. Bruce McEwen, to follow the path of stress
into the brain. [MUSIC] They subjected lab rats to chronic stress,
and then examined their brain cells. The team made an astonishing find. While
the cells of normal rat brains have extensive branches, stressed rats
brain cells were dramatically smaller. >> And, what was most interesting in many
ways was the part of the brain where this was happening--hippocampus. You take Intro
Neurobiology any time for the last 5,000 years, and what you learn
is: hippocampus is learning and memory. >> Stress in these rats shrank the part of
their brain responsible for memory. >> Stress affects memory in two ways.
Chronic stress can actually change brain circuits, so that we lose the capacity to
remember things as we need to. Very severe acute stress can have another
effect, which is often we refer to as stress makes
you stupid, which is making it impossible for you in, over short periods of time to
remember things you know perfectly well. >> We all know that phenomenon, we all
know that one from back when, when we stressed ourselves by not getting
any sleep at all. And the next morning at 9 o'clock, we couldn't remember a single
thing for that final exam. You take a human and stress them big time,
long time, and you're going to have a hippocampus
that pays the price as well. >> Dr. Blackburn is a leader in the field
of telomere research. >> We have 46 chromosomes and they're
capped off at each end by telomeres. Nobody knew in humans whether telomeres
and their fraying down over life would be affected by chronic stress, and
so, we decided we would look at this cohort of chronically stressed
mothers. And we decided to ask what's happening to their telomeres
and to the maintenance of their telomeres. What we found was the length of the
telomeres directly relates to the amount of stress somebody is under,
and the number of years that they've been under the stress. >> Such stressed
mothers became the focus of a study by Dr. Blackburn's colleague, psychologist Elissa
Epel. [MUSIC] >> Mothers of young children are a highly
stressed group. They are often balancing competing demands
like work and child rearing, and often don't have time to take care of
themselves. So, if you add on top of that, the extra burden of caring for a child
with special needs, it can be overwhelming. It can tax the
very reserves that sustain people, and if they are stressed, if they report
stress, they tend to die earlier. >> These women have shortened telomeres,
decreased activity of this enzyme, and a very, very rough number, for every year
you're taking care of a chronically ill child, you got roughly six years worth of
aging. >> This is real, this is not just somebody whining--this is
real, medically serious aging going on, and we can see that it's actually caused
by the chronic stress. [WHOOSH SOUND]. >> But there is hope. Dr. Blackburn
co-discovered an enzyme, telomerase, that can repair the damage. >> It's what I
always call it the threat of hope. [LAUGHTER] [CROSSTALK]. >> That's good.
That's good. >> Yeah. >> Preliminary data suggests that a meeting of minds, such as
this, may actually have a health benefit, by stimulating the healing effects of
telomerase. >> [CROSSTALK] And laugh. >> And laugh. If you don't, if you don't
laugh, forget it, you can't handle it, it's... >> What I found is that the humor
is something--there's a certain level of black humor that we have about
our kids that only we appreciate, we are the only ones who get the jokes
and, in a way, we're the only ones who are allowed to
laugh at the jokes. >> Right. >> One of the questions in the
stress field is, you know, what are the active ingredients that
reduce stress and that promote longevity? And compassion and caring for others may
be one of those most important ingredients. So, those may
be the factors that promote longevity and increase telomerase, and keep ourselves
rejuvenating and regenerating. [MUSIC] >> So, perhaps connecting with and helping
others can help us to mend ourselves, and maybe even live longer, healthier lives.
Twenty years ago, Robert got a shocking preview of this
idea. The first troop he ever studied, the baboons he felt closest to and had
written books about, suffered a calamity. It would have a
profound effect on his research. >> The Keekorok troop is the one I started
with 30 years ago, and they were your basic old baboon troop at the time--and
which means males were aggressive, and society was highly stratified, and females
took a lot a grief, and your basic off-the-rack baboon troop. And
then about, by now almost 20 years ago, something horrific and scientifically very
interesting happened to that troop. >> The Keekorok troop took to foraging for food in the garbage dump of a popular
tourist lodge. It was a fatal move--the trash included
meat tainted with tuberculosis. The result was that nearly half the males
in the troop died. >> Not unreasonably, I got depressed as hell and pretty damn
angry about what happened. You know, you're 30 years old, you can afford to
expend a lot of emotion on a baboon troop, and there was a lot of emotion there. [MUSIC] >> For Robert, a decade of research
appeared to have been lost. But then he made a curious observation
about who had died and who had survived. >> It wasn't random who
died. In that troop, if you were aggressive, and if you were
not particularly socially connected, socially affiliative, you didn't spend
your time grooming and hanging out, if you were that kind of male, you died.
>> Every alpha male was gone. The Keekorok troop had been transformed.
>> And, what you were left with was twice as many
females as males. And the males who were remaining were, you know, just to use
scientific jargon, they were good guys. They were not aggressive jerks, they were
nice to the females, they were very socially affiliative---it completely
transformed the atmosphere in the troop. [MUSIC] >> When male baboons reach adolescence,
they typically leave their home troop and roam, eventually finding a new troop. >>
And when new adolescent males would join the
troop, they'd come in just as jerky as any
adolescent males elsewhere on this planet, and it would take them about six months to
learn...we're not like that in this troop. We don't do stuff like that. We're not
that aggressive. We spend more time grooming each other.
Males are calmer with each other. You do not dump on a female if you're in a
bad mood. And it takes these new guys about six months, and they assimilate this
style, and you have baboon culture in this particular troop has a
culture of very low levels of aggression, and high levels of social affiliation, and
they're doing that 20 years later. >> And so the tragedy had provided Robert with a
fundamental lesson, not just about cells, but how the absence of stress could impact
society. >> Do these guys have the same problems with high blood pressure? Nope.
Do these guys have the same problems with brain chemistry related to anxiety, stress
hormone levels? Not at all. It's not just your rank, it's what your
rank means in your society. >> And the same is true for humans, with only a slight variation. >>
We belong to multiple hierarchies. And you may have the worst job in your
corporation, and no autonomy and control of predictability, but you're the
captain of the company softball team that year. And you better bet you are going to
have all sorts of psychological means to decide it's just a job, nine to five,
that's not what the world is about--what the world's about is softball. I'm the
head of my team, people look up to me. And you come out of that deciding you are
on top of the hierarchy that matters to you. [CAGE SOUNDS] Well, that worked. Damn, lots of baboon poop...
Which, under the right circumstances, with the
right season's experiment is a gold mine. Unfortunately, this time around it's just
a cage to have to clean now. [MUSIC] I'm studying stress for 30 years now, and
I even tell people how they should live differently--so, presumably, I should have
incorporated all of this. And the reality is, like, I'm unbelievably
stressed, and type A, and poorly coping, and, like, why else
would I study this stuff 80 hours a week? No doubt everything I advise is going to
lose all its credibility if I keel over dead from a heart attack in my early 50s.
Nah, I'm not good at dealing with stress. You know, one thing that works to my
advantage is I love my work and I love every aspect of it, so that's
good... Nonetheless, this is pretty clearly a different place
than the savanna in East Africa. You know, you can do science here that's
very different and more interesting in some ways. You can
have hot showers on a more regular basis. It's a more interesting, varied world in
lots of ways, but, you know, there's a lot out there that you
sure miss. [MUSIC] It is a pretty miraculous place, where
every meal tastes good, and you're ten times more aware of every
sensation. [MUSIC] This is a hard place to come to year after
year without getting, I think, a very different metabolism and
temperament. I'm more extroverted here... I'm more, more happy... This is a hard
place not to be happy. [MUSIC]
