Study Shows How Stress Triggers Immune System01/23/12
MONDAY, Jan. 23 (HealthDay News) -- Shedding some light on why
stress might be bad for you, a new study finds that parts of your
immune system ramp up when you get into personal conflicts with
It's not clear how this effect of stress may make you sick, but
the activated parts of the immune system -- which cause
inflammation in the body -- have been linked to conditions such as
diabetes and cancer.
"The message is that the flotsam and jetsam of life predict changes in your underlying biology in ways that cumulatively could have a bad effect on health," said study co-author Shelley Taylor, a professor of psychology at the University of California, Los Angeles. "What this tells me is that people should be investing in socially supportive relationships, and they should not court relationships that lead to a great deal of conflict."
It's well-known that stress causes several reactions in the
body. "Stress activates the immune system in preparation for
fighting infection and healing wounds," explained Dr. Andrew
Miller, a professor of psychiatry and behavioral sciences at Emory
University School of Medicine, in Atlanta. "This is not a bad
thing, especially in the context of a situation where a fight and
wounding may ensue. However, if the immune system is constantly
activated, this can contribute to a multitude of chronic health
problems, including cardiovascular disease, diabetes, cancer and
In the new study, researchers sought to determine whether the
stress of personal conflicts and competitive sports would trigger
the release of molecules known as cytokines, which are linked to
The researchers paid 122 young adults (53 men and 69 women) to
take part in the study. The participants filled out diaries about
their activities over eight days, focusing on their interactions
with others and whether these were positive or negative. The
participants were also given stress tests in the lab. Saliva
samples were taken before and after those tests, to measure
biological markers for inflammation.
The researchers found that cytokine levels went up after
"negative" interactions, usually arguments. But playing sports
didn't have the same effect, even though it's competitive. This may
be because "we're really talking about people doing friendly
games," Taylor said. "We're not looking at USC playing in the
It's possible that some kinds of competitions, like poker games,
could trigger inflammation, she said.
Why does it matter if stress triggers molecules linked to
inflammation? "If you aren't wounded, there's no place for them to
go, and they're circulating," Taylor said. "It's not like they've
gone to the site of a wound and engaged in anti-infection
Low-grade inflammation in the body can contribute to the buildup
of artery-blocking plaque and contribute to disorders linked to an
out-of-control immune system, such as asthma, Taylor said.
So what does this all mean? The challenge, Emory's Miller said,
is figuring out which came first -- stress or inflammation.
"Do aggressive, socially disadvantaged individuals exhibit more inflammation because they are constantly stressed?" he asked. "Or are they running their immune system hot because that is their fundamental nature, and the cytokines are driving their aggression because cytokines induce the brain to perceive the world as threatening?"
The study appears in this week's issue of the
Proceedings of the National Academy of Sciences.
For more about
stress, visit the U.S. National Library of Medicine.
Copyright © 2012
. All rights reserved.
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.