Learning about stress

00:12
I have a confession to make.
00:16
But first, I want you to make a little confession to me.
00:23
In the past year, I want you to just raise your hand
00:26
if you've experienced relatively little stress.
00:29
Anyone?
00:32
How about a moderate amount of stress?
00:35
Who has experienced a lot of stress?
00:38
Yeah. Me too.
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But that is not my confession.
00:42
My confession is this:
00:44
I am a health psychologist,
00:46
and my mission is to help people be happier and healthier.
00:51
But I fear that something I've been teaching
00:54
for the last 10 years is doing more harm than good,
00:59
and it has to do with stress.
01:01
For years I've been telling people, stress makes you sick.
01:04
It increases the risk of everything from the common cold
01:07
to cardiovascular disease.
01:10
Basically, I've turned stress into the enemy.
01:14
But I have changed my mind about stress,
01:17
and today, I want to change yours.
01:21
Let me start with the study that made me rethink
01:23
my whole approach to stress.
01:26
This study tracked 30,000 adults in the United States for eight years,
01:30
and they started by asking people,
01:33
"How much stress have you experienced in the last year?"
01:37
They also asked,
01:38
"Do you believe that stress is harmful for your health?"
01:44
And then they used public death records to find out who died.
01:48
(Laughter)
01:49
Okay.
01:51
Some bad news first.
01:53
People who experienced a lot of stress in the previous year
01:56
had a 43 percent increased risk of dying.
02:00
But that was only true for the people
02:04
who also believed that stress is harmful for your health.
02:08
(Laughter)
02:10
People who experienced a lot of stress
02:13
but did not view stress as harmful
02:15
were no more likely to die.
02:16
In fact, they had the lowest risk of dying
02:20
of anyone in the study,
02:21
including people who had relatively little stress.
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Now the researchers estimated that over the eight years
02:27
they were tracking deaths,
02:29
182,000 Americans died prematurely,
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not from stress,
02:33
but from the belief that stress is bad for you.
02:37
(Laughter)
02:38
That is over 20,000 deaths a year.
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Now, if that estimate is correct,
02:44
that would make believing stress is bad for you
02:47
the 15th largest cause of death in the United States last year,
02:51
killing more people than skin cancer, HIV/AIDS and homicide.
02:57
(Laughter)
02:59
You can see why this study freaked me out.
03:02
Here I've been spending so much energy telling people
03:06
stress is bad for your health.
03:09
So this study got me wondering:
03:10
Can changing how you think about stress make you healthier?
03:14
And here the science says yes.
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When you change your mind about stress,
03:18
you can change your body's response to stress.
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Now to explain how this works,
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I want you all to pretend that you are participants
03:27
in a study designed to stress you out.
03:29
It's called the social stress test.
03:32
You come into the laboratory,
03:34
and you're told you have to give
03:36
a five-minute impromptu speech on your personal weaknesses
03:41
to a panel of expert evaluators sitting right in front of you,
03:44
and to make sure you feel the pressure,
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there are bright lights and a camera in your face,
03:49
kind of like this.
03:51
(Laughter)
03:52
And the evaluators have been trained
03:55
to give you discouraging, non-verbal feedback,
03:59
like this.
04:05
(Exhales)
04:06
(Laughter)
04:09
Now that you're sufficiently demoralized,
04:11
time for part two: a math test.
04:14
And unbeknownst to you,
04:16
the experimenter has been trained to harass you during it.
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Now we're going to all do this together.
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It's going to be fun.
04:24
For me.
04:25
Okay.
04:26
(Laughter)
04:27
I want you all to count backwards from 996
04:31
in increments of seven.
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You're going to do this out loud,
04:34
as fast as you can,
04:36
starting with 996.
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Go!
04:39
(Audience counting)
04:41
Go faster. Faster please.
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You're going too slow.
04:45
(Audience counting)
04:46
Stop. Stop, stop, stop.
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That guy made a mistake.
04:49
We are going to have to start all over again.
04:51
(Laughter)
04:52
You're not very good at this, are you?
04:55
Okay, so you get the idea.
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If you were actually in this study,
04:58
you'd probably be a little stressed out.
05:00
Your heart might be pounding,
05:01
you might be breathing faster, maybe breaking out into a sweat.
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And normally, we interpret these physical changes as anxiety
05:09
or signs that we aren't coping very well with the pressure.
05:13
But what if you viewed them instead
05:15
as signs that your body was energized,
05:17
was preparing you to meet this challenge?
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Now that is exactly what participants were told
05:23
in a study conducted at Harvard University.
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Before they went through the social stress test,
05:29
they were taught to rethink their stress response as helpful.
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That pounding heart is preparing you for action.
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If you're breathing faster, it's no problem.
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It's getting more oxygen to your brain.
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And participants who learned to view the stress response
05:44
as helpful for their performance,
05:46
well, they were less stressed out, less anxious, more confident,
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but the most fascinating finding to me
05:52
was how their physical stress response changed.
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Now, in a typical stress response,
05:57
your heart rate goes up,
05:59
and your blood vessels constrict like this.
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And this is one of the reasons that chronic stress
06:06
is sometimes associated with cardiovascular disease.
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It's not really healthy to be in this state all the time.
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But in the study,
06:14
when participants viewed their stress response as helpful,
06:17
their blood vessels stayed relaxed like this.
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Their heart was still pounding,
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but this is a much healthier cardiovascular profile.
06:25
It actually looks a lot like what happens
06:28
in moments of joy and courage.
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Over a lifetime of stressful experiences,
06:35
this one biological change
06:39
could be the difference
06:40
between a stress-induced heart attack at age 50
06:43
and living well into your 90s.
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And this is really what the new science of stress reveals,
06:49
that how you think about stress matters.
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So my goal as a health psychologist has changed.
06:56
I no longer want to get rid of your stress.
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I want to make you better at stress.
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And we just did a little intervention.
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If you raised your hand and said
07:05
you'd had a lot of stress in the last year,
07:07
we could have saved your life,
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because hopefully the next time your heart is pounding from stress,
07:12
you're going to remember this talk
07:14
and you're going to think to yourself,
07:16
this is my body helping me rise to this challenge.
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And when you view stress in that way,
07:24
your body believes you,
07:26
and your stress response becomes healthier.
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Now I said I have over a decade of demonizing stress
07:34
to redeem myself from,
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so we are going to do one more intervention.
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I want to tell you
07:40
about one of the most under-appreciated aspects of the stress response,
07:43
and the idea is this:
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Stress makes you social.
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To understand this side of stress,
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we need to talk about a hormone, oxytocin,
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and I know oxytocin has already gotten as much hype as a hormone can get.
07:58
It even has its own cute nickname, the cuddle hormone,
08:02
because it's released when you hug someone.
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But this is a very small part of what oxytocin is involved in.
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Oxytocin is a neuro-hormone.
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It fine-tunes your brain's social instincts.
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It primes you to do things
08:17
that strengthen close relationships.
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Oxytocin makes you crave physical contact with your friends and family.
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It enhances your empathy.
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It even makes you more willing to help and support
08:30
the people you care about.
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Some people have even suggested we should snort oxytocin...
08:39
to become more compassionate and caring.
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But here's what most people don't understand about oxytocin.
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It's a stress hormone.
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Your pituitary gland pumps this stuff out
08:54
as part of the stress response.
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It's as much a part of your stress response
08:58
as the adrenaline that makes your heart pound.
09:02
And when oxytocin is released in the stress response,
09:04
it is motivating you to seek support.
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Your biological stress response
09:10
is nudging you to tell someone how you feel,
09:13
instead of bottling it up.
09:16
Your stress response wants to make sure you notice
09:19
when someone else in your life is struggling
09:21
so that you can support each other.
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When life is difficult,
09:25
your stress response wants you to be surrounded
09:30
by people who care about you.
09:33
Okay, so how is knowing this side of stress going to make you healthier?
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Well, oxytocin doesn't only act on your brain.
09:40
It also acts on your body,
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and one of its main roles in your body
09:44
is to protect your cardiovascular system from the effects of stress.
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It's a natural anti-inflammatory.
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It also helps your blood vessels stay relaxed during stress.
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But my favorite effect on the body is actually on the heart.
09:59
Your heart has receptors for this hormone,
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and oxytocin helps heart cells regenerate
10:06
and heal from any stress-induced damage.
10:10
This stress hormone strengthens your heart.
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And the cool thing is that all of these physical benefits
10:18
of oxytocin are enhanced by social contact and social support.
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So when you reach out to others under stress,
10:26
either to seek support or to help someone else,
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you release more of this hormone,
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your stress response becomes healthier,
10:34
and you actually recover faster from stress.
10:37
I find this amazing,
10:39
that your stress response has a built-in mechanism
10:43
for stress resilience,
10:46
and that mechanism is human connection.
10:51
I want to finish by telling you about one more study.
10:54
And listen up, because this study could also save a life.
10:58
This study tracked about 1,000 adults in the United States,
11:01
and they ranged in age from 34 to 93,
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and they started the study by asking,
11:08
"How much stress have you experienced in the last year?"
11:12
They also asked,
11:14
"How much time have you spent helping out friends, neighbors,
11:18
people in your community?"
11:22
And then they used public records for the next five years
11:24
to find out who died.
11:27
Okay, so the bad news first:
11:30
For every major stressful life experience,
11:33
like financial difficulties or family crisis,
11:36
that increased the risk of dying by 30 percent.
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But -- and I hope you are expecting a "but" by now --
11:44
but that wasn't true for everyone.
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People who spent time caring for others
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showed absolutely no stress-related increase in dying.
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Zero.
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Caring created resilience.
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And so we see once again
12:01
that the harmful effects of stress on your health
12:04
are not inevitable.
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How you think and how you act
12:09
can transform your experience of stress.
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When you choose to view your stress response as helpful,
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you create the biology of courage.
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And when you choose to connect with others under stress,
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you can create resilience.
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Now I wouldn't necessarily ask for more stressful experiences in my life,
12:35
but this science has given me a whole new appreciation for stress.
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Stress gives us access to our hearts.
12:45
The compassionate heart that finds joy and meaning
12:49
in connecting with others,
12:51
and yes, your pounding physical heart,
12:54
working so hard to give you strength and energy.
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And when you choose to view stress in this way,
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you're not just getting better at stress,
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you're actually making a pretty profound statement.
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You're saying that you can trust yourself to handle life's challenges.
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And you're remembering that you don't have to face them alone.
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Thank you.
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(Applause)
13:32
Chris Anderson: This is kind of amazing, what you're telling us.
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It seems amazing to me that a belief about stress
13:39
can make so much difference to someone's life expectancy.
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How would that extend to advice,
13:45
like, if someone is making a lifestyle choice
13:47
between, say, a stressful job and a non-stressful job,
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does it matter which way they go?
13:54
It's equally wise to go for the stressful job
13:56
so long as you believe that you can handle it, in some sense?
13:59
KM: Yeah, and one thing we know for certain
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is that chasing meaning is better for your health
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than trying to avoid discomfort.
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And so I would say that's really the best way to make decisions,
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is go after what it is that creates meaning in your life
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and then trust yourself to handle the stress that follows.
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CA: Thank you so much, Kelly. It's pretty cool.
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(Applause)