Healthy Olfactory Information Processing Is a Prerequisite for Odors to Alter Physiological Processes: A Randomized, Controlled Proof-of-Concept Study Involving Individuals with Temporary Anosmia

Objective: Anosmia, a medical condition with a plethora of etiologies, has shown to be notoriously challenging to treat. It is often reduced to the observation that odors cannot be “smelled” or identified. No research has so far been conducted to assess whether anosmia is only limited to a loss of smell or if the neural olfactory information processing also impairs the physical response to odor stimuli.

Methods: Individuals with temporary sinonasal anosmia were subjected to different inhalation protocols and control conditions. The physiological parameters assessed were arterial blood oxygenation, blood pressure, and heart rate variability.

Results: Contrary to the large effects found in previous research with healthy persons, none of the parameters showed meaningful effects in individuals suffering from anosmia.

Conclusion: The findings suggest that uninhibited olfactory information processing in the brain is a prerequisite for the functional mechanisms of odors to alter physiological processes.

Cite this article as: Schneider R, Singer N, Singer T. Healthy olfactory information processing is a prerequisite for odors to alter physiological processes: A randomized, controlled proof-of-concept study involving individuals with temporary anosmia. Eur J Rhinol Allergy 2022;5(3):77-83.