High sulfur and nitrogen foods are the main triggers of parosmia

PURPOSE: Parosmia is a condition associated with a significant impact on quality of life. Although its pathophysiology remains poorly understood, certain aromas and fragrances are frequently reported as triggers. This study aimed to identify the primary triggers of parosmia and analyze their molecular similarities. METHODS: This cross-sectional study included individuals with current complaints of parosmia. Data were prospectively collected via an online survey that assessed the most commonly reported triggers and associated perceptions. A perfumer analyzed the molecular characteristics of these substances. RESULTS: A total of 102 individuals with parosmia were included. The most frequently reported triggers were onion (68%), garlic (62.9%), coffee (49.5%), and beef (48.5%). These substances share sulfur-containing, nitrogenous, and thioester components, characterized by high olfactory potency and sensory notes described as "rotten," "sulfurous," and "roasted/burnt." The most associated perceptions were sewage (71%) and burnt (37.6%). CONCLUSION: The primary triggers of parosmia appear to share significant molecular similarities. This knowledge may contribute to a better understanding of the pathophysiology of parosmia and serve as a preliminary step toward developing new therapeutic approaches for this disorder.