Short bursts of stress can be good for your health: study

Researchers at Stanford University in the US, who have been investigating the beneficial effects of worry and pressure have said that injections of stress hormones might be beneficial for those about to undergo surgery or anyone having a vaccination, in order to 'turbo charge' the immune system's response.

The new study has pinpointed exactly how stress boosts the immune system.

The researchers subjected rats to frequent blood tests, which caused them to be stressed, the Daily Mail reported.

They monitored the changes in blood levels of three hormones (norepinephrine, epinephrine and cortisol) released when the brain feels the body is under threat.

They found that when the rats were stressed, the brain immediately ordered the carefully choreographed release of each hormone in a particular order - norepinephrine first, then epinephrine and finally cortisol.

Each hormone appeared to have a specific role in dispatching disease-fighting immune system cells to different parts of the body to defend against attack.

Norepinephrine, for example, had the job of mobilising cells into the bloodstream.

Epinephrine, on the other hand, appeared to be in charge of sending them to the skin to act as protection in case of injury.

This response, amassing protective cells in areas most at risk of attack, lasted only around two hours and was likened by researchers to mustering troops in a crisis.

However, the key to these benefits is that a person only suffers from a fleeting moment of stress - chronic, long-term stress has been shown to suppress the immune system by lowering the levels of white blood cells, which form a crucial part of the body's defences against infections.

"You don't want to keep your immune system on high alert at all times. But the evidence does suggest that putting oneself under short-term stress during procedures like vaccination or surgery can boost immune defences," Professor Firdaus Dhabhar, who led the research, said.

"The key is that the stress really has to be short-term, lasting only for minutes or hours. It involves a rapid activation of the biological stress response followed by a rapid shutdown soon after the challenge is over," Dhabhar was quoted as saying by the paper.