Mild stress boosts the immune system

Chronic stress is bad, but there is a silver lining. A new study reveals that short-term stress can boost the immune system. It may be that one day the ability to manipulate stress-hormone levels will help to improve patients’ responses to vaccines or even to recovery from surgery or injuries.

Fight-or-flight is meant to help

Chronic, long-term stress negatively impacts health by suppressing the immune response. The immune system plays a vital role in protecting our bodies from disease. However, lead author of this new study, Firdaus Dhabhar, PhD, an associate professor of psychiatry and behavioral sciences and member of the Stanford Institute for Immunity, Transplantation, and Infection, explained that short-term stress actually stimulates immune activity. “Mother Nature gave us the fight-or-flight stress response to help us, not kill us,” explained Dhabhar.

Coordinated system detects danger and protects the body

“You don’t want to keep your immune system on high alert at all times. So nature uses the brain, the organ most capable of detecting an approaching challenge, to signal that detection to the rest of the body by directing the release of stress hormones. Without the, a lion couldn’t kill, and an impala couldn’t escape,” said Dhabhar.

Researchers relied on rats for their study. They subjected them to mild stress and the team drew blood samples to test for immune cells. The team found that immune cells were dispatched by three hormones: norepinephrine, epinephrine and coricosterone. Researchers then administered the three hormones in various combination to see the reaction on the rats’ bodies.

Stress hormones ultimately boost immunities

They found that norephinephrine is released early and helps transport immune cells such as lymphocytes, monocytes and neutrophils into the blood. Other hormones had a similar effect as well. The result was a boost to the immune system. Human testing awaits.

Source: MedicalNewsToday, Journal of Psychneuroendocrinology