I
n a study released two weeks ago,
California scientists announced they had found the
first direct link between emotional stress and signs
of premature aging.The
study, which was widely praised by other
researchers, strengthens the popular belief that
emotional stress may have serious medical
consequences. It is also consistent with the idea
that stress-reducing practices such as yoga,
meditation, jogging or any kind of real relaxation
may reduce the risk of certain diseases.
Previous studies have shown that
chronic stress is linked to a higher risk of heart
attack, high blood pressure and insomnia, said Dr.
Herbert Benson, president of the Boston-area
Mind/Body Medical Institute and an associate
professor of medicine at Harvard Medical School.
Stress is also associated with more intense hot
flashes, a lower threshold for pain, and increased
anxiety, depression, excessive anger and hostility.
But, before you stress out about
the ill effects of stress, a few cautions: Many of
the biochemical links between feeling stressed and
getting sick are still unknown. And stress clearly
doesn't cause everything.
''For a long time, people believed
that stress caused cancer. It's not true," said
psychologist Barrie Cassileth, chief of the
integrative medicine service at Memorial
Sloan-Kettering Cancer Institute in New York.
Several studies have looked at people who have lost
a child, been in concentration camps or psychiatric
wards or who were prisoners of war -- and found no
link between those stressful situations and cancer.
The new study is ''a very
important milestone" in mind-body research, said
Bruce McEwen, director of neuroendocrinology at
Rockefeller University in New York.
In a commentary accompanying the
California paper in the Proceedings of the National
Academy of Sciences, Robert Sapolsky of Stanford
University wrote that the discovery is ''remarkable"
and ''exciting" because it ties together an
emotional state with very fundamental cell biology.
In the study, researchers from the
University of California at San Francisco followed
58 women ages 20 to 50. Thirty-nine of the women had
been caring for a chronically ill child for as long
as 12 years, and the rest were raising healthy
children. All the women were healthy.
But, in women who were more
stressed, as gauged both by their subjective ratings
and the duration of their care-giving, cells showed
signs of premature aging. Their telomeres, tiny
structures on the ends of chromosomes, were
shriveling up faster than normal. Like the tips of
shoelaces, telomeres protect the ends of
chromosomes; once telomeres get too short, a cell
can no longer divide.
The longer a woman took care of a
sick child, the shorter were the telomeres in her
white blood cells, said lead author Elissa Epel, a
UCSF psychologist. The women who felt most stressed
also had lower levels of telomerase, an enzyme that
restores telomere length. And they had greater
''oxidative stress," a measure of damage done to
cells by destructive forms of oxygen, noted
Elizabeth Blackburn , a coauthor and UCSF professor
of biochemistry and biophysics.
The women whose subjective ratings
of stress were the highest had the equivalent of 10
years of extra aging in their immune cells, compared
to women in both groups who rated their stress
lower, Epel said.
''It's how you perceive stress
that is important, not care-giving per se," Epel
said, adding that the same external situation can
produce different kinds of stress in different
people.
One implication is that if you're
in what you perceive to be an unpleasantly stressful
situation, change the situation if you can; if you
can see the situation in a less-stressful light,
that may help, too, though this can be hard to do.
The California study is actually
the latest in a series of findings documenting a
link between chronic stress and disease or immune
system disruption.
In one 1999 study, University of
Pittsburgh researchers found that people who were
taking care of an ill spouse and experiencing stress
had a 63 percent higher risk of death over a
four-year period than noncare-givers in the same
study.
At Ohio State University, the
husband-and-wife team of Janice Kiecolt-Glaser, a
psychologist, and Ronald Glaser, an immunologist,
have found that spouses who take care of partners
with dementia have weakened immune systems.
Small, experimentally produced
wounds, for instance, take longer to heal in
stressed care givers, and immune responses to
vaccinations are less vigorous. In a recent,
six-year study, the Glasers found that chronically
stressed caretakers pump out excessive quantities of
Il-6, an immune system chemical, that is linked to
heart disease, osteoporosis, arthritis, diabetes and
other conditions.
Like the California researchers,
the Glasers found that Il-6 levels in the stressed
care givers were as high as those of people 15 years
older, suggesting that stress may accelerate aging.
In terms of stress and heart
disease, the most impressive study to date is a
52-country study published earlier this year in the
Lancet. Called INTERHEART, the study examined stress
at home and at work, financial stress and major life
events in 24,767 people and found that stress raised
heart attack risk 2 times, almost as much as smoking
and diabetes.
Although previous studies had
suggested a correlation between chronic stress and
heart disease, this was the first time a large,
cross-country study showed such a clear link, said
Dr. Roger Blumenthal, director of preventive
cardiology at Johns Hopkins Hospital.
The implication, he said, is that
people ''should work harder at decreasing stress,
increasing exercise and making time for hobbies.
It's ironic, but you have to make time to get away
from stressors."
How? Basically, by relaxing with
whatever tricks work -- jogging, meditation,
repetitive prayer, even zoning out watching tropical
fish, said Benson of Harvard. There are two keys to
this: Repetition, that is, repeating a sound, a
word, a phrase or even a movement, like jogging or
swimming; and when other thoughts pop into your
mind, gently guide yourself back to your repetitive
phrase or activity.
''The common denominator in all
these things is that they break the train of
everyday thought," Benson said. ''If you can break
that chain, even for just 20 minutes a day, it gives
the body a chance to reconstitute."
