New Study Links Stress and Aging
Scientists Think Emotional Strain Increases Wear on Healthy Bodies
By Rob Stein
Washington Post Staff Writer
Monday, November 29, 2004; 5:24 PM
Scientists have identified the first direct link between stress and aging, a
finding that could explain why intense, long-term emotional strain can make
people get sick and grow old before their time.
Chronic stress appears to hasten the shriveling of the tips of the bundles of
genes inside cells, which shortens their lifespan and speeds the body's
deterioration, according to a small but first-of-its-kind study involving
mothers caring for chronically ill children.
If the findings are confirmed, they could provide the first explanation on a
cellular level for the well-documented association between psychological stress
and increased risk of physical disease, as well as the common perception that
unrelenting emotional pressure accelerates the aging process.
"There is this deeply held belief that stress leads to premature aging. But
there is no hard evidence for how this might happen," said Elissa Epel, a
psychiatrist at the University of California, San Francisco (UCSF), who helped
conduct the research. "This is the first time that psychological stress has
been linked to a cellular indicator of aging in healthy people."
The findings could lead to new ways to detect the early physical effects of
stress and monitor whether attempts to alleviate its effects are working, she
While cautioning that the findings needed to be confirmed by additional
research, other scientists said the results represent an unprecedented step in
deciphering the intricacies of the mind-body connection.
"This is a real landmark observation," said Robert M. Sapolsky of
Stanford University, who wrote a commentary accompanying the paper in Tuesday's
issue of the Proceedings of the National Academy of Sciences. "This is a
huge interdisciplinary leap . . . a great study."
Dennis H. Novack, who studies the link between emotions and health at Drexel
University School of Medicine, agreed.
"Everybody's trying to figure out what causes aging and premature aging. We
all know that stress seems to age people -- just look at the aging of our
presidents after four years," he said. The new study "demonstrated
that there is no such thing as a separation of mind and body -- the very
molecules in our bodies are responsive to our psychological environment."
Epel and her colleagues studied 39 women ages 20 to 50 who had been experiencing
grinding stress for years because they were caring for a child suffering from a
serious chronic illness, such as autism or cerebral palsy, and 19 other very
similar women whose children were healthy.
New Study Links Stress and Aging
The researchers examined structures inside cells called telomeres. Telomeres
are the caps at the ends of chromosomes -- the molecules that carry genes.
Every time a cell divides, telomeres get shorter. In the natural aging
process, the telomeres eventually get so short that cells can no longer
divide, and they then die.
The researchers also measured levels of an enzyme called telomerase, which
helps rebuild telomeres to stave off this process. Telomerase levels naturally
decline with age.
"This is an in-born glitch in the way nature has arranged things,"
said Elizabeth Blackburn, a professor of biology and physiology at UCSF who
helped conduct the study. "It's always a race, and over the long term we
eventually lose the race and age."
The researchers found that the longer a woman had been caring for a sick
child, the shorter her telomeres, the lower her levels of telomerase, and the
higher her levels of "oxidative stress." Oxidative stress is a
process in which so-called free radicals in the body damage DNA, including
The greater a woman's perception of her stress in the study, the worse she
scored on all these tests. Compared to women with the lowest levels of
perceived stress, women with the highest perceived stress had telomeres
equivalent to someone who was 10 years older, the researchers found.
"The shorter the telomeres, the higher the perceived stress and the lower
the telomerase," Blackburn said. "It was just the same with
oxidative stress -- the worse the perceived psychological stress, the greater
the oxidative stress. It all went in the same direction."
The researchers studied telomeres and telomerase in white blood cells taken
from blood samples. Prematurely aged white blood cells alone could make people
more prone to illness because they are a key part of the immune system. But
the findings likely hold true for other types of cells as well, Epel said, and
the researchers now plan to do studies to confirm that.
It's unclear exactly how stress might affect telomeres and telomerase levels,
but it could be that chronically elevated levels of stress hormones such as
cortisol damage the telomeres and other genes in the body and lower telomerase
levels, inhibiting the cells' ability to respond.
"That's the obvious hypothesis that jumps out," Blackburn said.
Whatever the mechanism, the findings indicate that doctors could monitor
telomere length and telomerase levels for signs that people under chronic
stress are suffering adverse effects, Epel said.
"Telomere length and telomerase may be used as a way to monitor health.
Very low telomerase or very short telomeres might serve as a kind of red
flag," Epel said.
If someone appears headed for trouble, doctors could recommend meditation,
Yoga or other stress-reduction techniques, she said.
"The findings emphasize the importance of managing life stress, to take
it seriously if one feels stressed, to give your body a break, and make life
changes that promote well-being," Epel said.