A new study from the University of Auckland has found that natural daylight strengthens the body’s ability to fight bacterial infections by enhancing the function of neutrophils, white blood cells that form the first line of immune defense. Published in Science Advances, the research used zebrafish models to observe immune responses under varying light conditions.
The results showed that neutrophils were significantly more effective at destroying bacteria during daylight hours. This light-dependent boost is regulated by the circadian clock, particularly the Per2 gene. Light exposure activates this gene via clock proteins like BMAL1 and PER2, triggering the production of antimicrobial molecules such as myeloperoxidase and elastase.
Interestingly, when these clock proteins were disrupted, the enhanced immune effect of daylight was lost, even under the same light conditions. The study provides new insight into the link between circadian rhythms, environmental light and immune system performance.
Researchers suggest that optimizing light exposure, especially in hospitals or among shift workers could improve immune health and infection outcomes.
Disclaimer: This article is for informational purposes only and does not substitute for professional medical advice, diagnosis or treatment.
