To understand the difference between good
stress and bad stress, said neuroscientist Robert Sapolsky,
consider the fact that a roller coaster ride lasts for
three minutes, not three days.
"There's a reason that we'll pay money to go on
a roller coaster and be terrified" for a brief period,
said the Stanford University professor.
This kind of stressful episode can be invigorating and
empowering, he said. Blood circulates better, senses are
heightened, memory sharpens, energy peaks and chemicals
producing pleasure increase in the brain.
But if that same stress continues for an extended period,
Sapolsky said, the body continues straight downhill.
His Stanford laboratory was among the first to document
the way sustained stress can damage the hippocampus, a
region of the brain central to learning and memory.
Under continued stress, neurons shrivel in another part
of the brain, the prefrontal cortex, the center of emotion
and executive function. Meanwhile, the amygdala, which
processes fear and anxiety, grows neurons, essentially
trapping us in a state of fear. The body stops its repair
work, compromising the immune system, and constant pressure
on the cardiovascular system eventually leads to high
blood pressure and heart disease, Sapolsky said.
Sapolsky, recipient of a MacArthur Foundation "genius"
grant for studying stress in groups of baboons, presented
his conclusions at a Mind and Life Institute conference
in Washington last month, where scientists reported on
leading-edge brain research and the effects of meditation
on healing and health.
When it comes to stress, Sapolsky said, many of us have
it all wrong.
"It's easy to say, 'Aha! The answer is having no
stress in my life!' " But the idea that we should
-- or could -- live without it, he said, is "nonsense."
The body's reaction to stress can become chronic and
pernicious. This doesn't happen because a physical threat
to safety continues for a long time, but because humans
-- endowed with imagination, memory and language -- have
the ability to create psychological stress, even when
no physical or emotional threat is present. Sapolsky,
author of the book "Why Zebras Don't Get Ulcers,"
calls this "adventitious suffering -- the pain of
what was, what will be, what could be or what someone
else is experiencing."
The body makes no distinction between immediate, in-your-face
stressors and chronic, in-your-imagination ones, Sapolsky
said. Faced with either kind of threat, the body reacts,
and when the threat is sustained psychologically, the
physically destructive stress response continues.
An individual's personality or the frame of mind in which
one encounters stress also can determine its health effects.
Ronald Glaser, a viral immunologist at Ohio State University
(OSU), studies the physical changes induced by everyday
stress. He and his wife, Jan Kiecolt-Glaser, a clinical
psychologist and researcher at OSU, were among the first
to test the effects of stress on the immune system.
In 1991, they took a sampling of college students on
the last day of a series of academic exams and inoculated
them with the hepatitis B vaccine. They then monitored
the antibody response in each. The students had been followed
a year and a half before the inoculations. Those who had
the least stress in their everyday lives, or who had greater
social support, had more-robust immune system reactions
to the vaccine than the others.
The lesson: Those who encounter stress from a position
of psychological strength and social alliances withstand
stress better.
According to Sheldon Cohen, a psychology professor at
Carnegie Mellon University, the medical literature demonstrates
a link between chronic stress and depression, upper respiratory
infections, cardiovascular disease and HIV progression.
But understanding why these deleterious reactions occur,
explained Glaser, is "big-time complexity" involving
the central nervous, endocrine and immune systems and
how they "talk" to each other. Researchers don't
completely understand it yet.
What is known is that stress hormones -- cortisol, ACTH,
prolactin, growth hormone, epinephrine and norepinephrine
-- increase when a person is under stress. They bind to
receptors in blood cells and change what the cells do
in the body, Glaser says.
To explain how different people respond to chronic stress,
Sapolsky used the analogy of living in New York: For someone
with good mental health and a strong social support system,
he said, the city offers an exciting life and an intense,
beneficial sensory experience -- good stress. But if you
are someone who has developed a lot of scar tissue putting
up with what the city can throw at you, or you live in
a place with no running water and drug dealers on the
corner, the city and its stressors can be "one more
nail in your coffin."
Letting adventitious suffering get the better of you
can do the same. It's important to realize that while
it feels real and has real effects, it is a creation of
humans' ability to empathize and worry.
Simply recognizing that may make it easier to turn stress
that results from adventitious suffering into productive
stimulation, Sapolsky said.
Meditation, Sapolsky said, can focus the mind and bring
the roots of your stress into awareness. For some, merely
taking stock can do the same.
Or you might follow the simple advice of Barrie Cassileth,
who heads integrative medicine services at Memorial Sloan-Kettering
Cancer Center in New York.
"Close your eyes for a minute, take a deep breath,
think about people dying in other parts of the world.
Refocus, and get back to work."
