Watching a child
cry while they get poked by a needle can be gut-wrenching, but the stress
experienced by the child may actually be beneficial. While stress has long held a bad reputation
for being harmful, recent evidence provide a new perspective on the influence
of stress on human health. Although
chronic psychological stress is associated with immune dysfunction and
increased risk for a wide variety of conditions/diseases, acute stress enhances
many feature of the immune system and actually can protect an organism from disease.
Firdaus
Dhabhar and his colleagues at Stanford University found that exposing mice to
acute stress before they were vaccinated boosted the immune system and made the
vaccines more effective. Dhabhar
observed similar results in humans. Patients
anticipating knee-surgery increased the number of immune cells circulating in
the bloodstream in the days preceding the operation and had better
post-operation recovery compared to non-stressed patients. These results seem to make sense from an
evolutionary perspective; just as the acute stress response increases the
functioning of the cardiovascular system to prepare for fight-or-flight, acute stress
also appears to improve the immune system in the case of injury or infection. While the underlying
mechanisms for these findings remain unclear, there is some evidence that these
effects are mediated by stress-induced hormones, danger-associated molecular
patterns (DAMPs), microbial associated molecular patterns (MAMPs), and the inflammasome. Regardless of the mechanism, it appears safe to conclude feeling anxious
about receiving a shot is something that should be celebrated not embarrassed about
(even if you are no longer a child).
