
New research from the University of Alberta suggests that allowing mild fever to run its course may have health benefits, as untreated moderate fever in fish helps clear infections quickly and control the inflammation. Although the benefits of natural fever for humans have yet to be confirmed, researchers believe that similar benefits are likely due to fever mechanisms shared across the animal kingdom.
Studies in fish suggest that delaying drug use may benefit humans.
According to new research from the University of Alberta, it may be better to let a mild fever take its natural course rather than immediately resorting to medication.
Researchers found that leaving low-grade fever in fish untreated helped them quickly clear the infection from their bodies, regulate inflammation, and repair any damaged tissue. “We let nature do what nature does, and in this case, that was a very positive thing,” says immunologist Daniel Barreda, lead author of the study and associate professor at the Faculty of Science of the Institute. Agriculture, Life and Environment and at the Faculty. science.
A moderate fever resolves on its own, which means the body can both induce and stop it naturally without medication, Barreda explains. The health benefits of natural fever for humans have yet to be confirmed by research, but the researchers say that because the mechanisms leading to and maintaining fever are shared between animals, it is reasonable to expect that that similar benefits occur in humans.
This suggests we should resist over-the-counter fever medications, also called nonsteroidal anti-inflammatory drugs, at the first signs of mild temperatures, he says. “They take away the discomfort felt with the fever, but you’re also probably giving some of the benefits of that natural response.”

Using a custom swim chamber to study the behavioral response of fish to fever, researchers Daniel Barreda, Amro Soliman, Farah Haddad and their team found that mild fever helped fish clear infection quickly, control inflammation and repair tissue damage. Credit: University of Alberta
The study helps shed light on the mechanisms that contribute to the benefits of moderate fever, which Barreda says has been evolutionarily conserved in the animal kingdom for 550 million years. “Every animal examined has this biological response to infection.”
For the study, the fish received a bacterial infection and their behavior was then tracked and assessed using
Reference: “Fever integrates antimicrobial defences, inflammation control and tissue repair in a cold-blooded vertebrate” by Farah Haddad, Amro M Soliman, Michael E Wong, Emilie H Albers, Shawna L Semple, Débora Torrealba , Ryan D Heimroth, Asif Nashiry, Keith B Tierney and Daniel R Barreda, March 14, 2023, eLife.
DOI: 10.7554/eLife.83644