Cognitive performance during the pollen season: how much of a restriction is hay fever?
Runny nose, itchy eyes: even a small concentration of pollen in the air can trigger a reaction in allergy sufferers. Researchers from the University of Basel and the Swiss Tropical and Public Health Institute have now investigated whether allergic reactions such as these influence cognitive performance.
23 April 2025 | Shania Imboden
For allergy sufferers, it is difficult to enjoy spring. Almost as soon as nature begins to blossom again after winter, pollen spreads through the air. With climate change prolonging the pollen season, people are suffering from allergies for longer and many feel restricted in their day-to-day lives – including cognitively. Watery eyes, a stuffy nose or headaches can limit allergy sufferers in carrying out their tasks.
A group of researchers led by Dr. Marloes Eeftens from the Swiss Tropical and Public Health Institute (Swiss TPH) has now investigated the extent to which pollen load actually influences cognitive performance. The scientists reported on their findings in Environmental Epidemiology.
A focus on individual allergies
392 adults from the Basel region took part in the study, 299 of whom had a verified pollen allergy. “It can often be difficult to find subjects for studies. But there was a lot of interest here,” says Baylee Corpening, lead author of the study. The researchers explain this by the fact that many of those affected do not always feel like their complaints are taken seriously. There was therefore a great deal of interest in having these complaints investigated from a scientific standpoint.
The researchers performed skin prick tests prior to the study to determine each subject’s personal allergy season. The investigations began at the start of the respective season: the study participants completed four online tests of their cognitive performance each day for ten days. Among other things, the tests examined attention, ability to concentrate, reaction time, and verbal and visual-spatial memory.
Self-perception is misleading
These tests did not reveal any significant correlation between pollen count and cognitive performance in allergy sufferers. “Tests like these are often used to test people with mild cognitive impairments. However, they may not be sensitive enough to detect minor cognitive changes in otherwise healthy individuals,” explains Baylee Corpening.
But some participants rated their own performance as worse than shown by the data collected. “Mood has a huge impact on this self-assessment. An active lifestyle, along with the consumption of coffee, alcohol or medication, can also change how we perceive our own performance,” says Corpening. Subjective perception and objective data therefore often differ from one another.
Little research has yet been carried out
Unlike pollutants from anthropogenic sources, the effects of pollen on health have only been researched to a limited extent. The research team led by Marloes Eeftens is conducting several studies to systematically investigate the effects of pollen on physical and mental health and performance. The topic is becoming increasingly important as more and more people develop allergies.
An estimated 20 percent of the Swiss population are allergic to at least one type of pollen. It is suspected that the Western lifestyle may be one reason for this. “Processed foods, frequent use of antibiotics and a lifestyle increasingly detached from nature are making our immune systems more reactive to harmless environmental influences such as pollen,” says Marloes Eeftens.
Original publication
Corpening Baylee et al.
Associations between ambient pollen exposure and measures of cognitive performance
Environmental Epidemiology (2025), doi: 10.1097/EE9.0000000000000374
