GLP-1 receptor agonists significantly impair taste function

• Published in: Physiology & behavior Vol. 291; p. 114793
• Main Authors: Khan, Rafa, Doty, Richard L.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.03.2025
• Subjects: Adult; behavior; brain stem; COVID-19; COVID-19 infection; diarrhea; Female; GLP-1 receptor agonists; glucagon-like peptide 1; Glucagon-Like Peptide-1 Receptor Agonists; Humans; Male; Middle Aged; nausea; Obesity; Olfaction; Pennsylvania; sensory evaluation; sensory system; smell; Smell - drug effects; Taste; Taste - drug effects; Taste Disorders - chemically induced; UPSIT; variance; WETT; Pennsylvania; UPSIT; Obesity; Taste; GLP-1 receptor agonists; WETT; Olfaction
• ISSN: 0031-9384; 1873-507X; 1873-507X
• DOI: 10.1016/j.physbeh.2024.114793

•GLP-1 agonists decrease objective measures of taste function.•Perception of all 5 basic taste qualities is depressed by GLP-1 agonists.•GLP-1 agonist side effects (e.g. nausea) greater in those with better taste & smell. Over 10% of the US population are prescribed glucagon-like peptide-1 receptor agonists (GLP-1 RAs) to combat obesity. Although they decrease cravings for foods, their influence on chemosensory function is unknown. We employed state-of-the-art quantitative taste and smell tests to address this issue. The 53-item Waterless Empirical Taste Test (WETT®) and the 40-item University of Pennsylvania Smell Identification Test (UPSIT®) were completed by 46 persons taking GLP-1 RAs and 46 controls matched on age, sex, smoking behavior, and COVID-19 infection histories. Data were analyzed using analyses of variance. The WETT® scores were significantly diminished in the GLP-1 RA group relative to controls [total means (95% CIs) = 28.61 (25.66,31.56) and 40.63 (38.35,42.91), p < 0.001, η2 = 0.37]. Eighty five percent of the GLP-1 subjects scored worse than their individually matched controls. All 5 WETT® subtest scores were similarly affected (ps < 0.001). Smell function, although slightly decreased on average, was not significantly impacted (p = 0.076). Women outperformed men on all tests. Remarkably, UPSIT® and WETT® scores were higher, i.e., better, in those reporting nausea, diarrhoea, and other GLP-1-related side effects. This study demonstrates, for the first time, that GLP-1 RAs alter the function of a major sensory system, significantly depressing the perception of all five basic taste qualities. The physiologic basis of this effect is unknown but may involve GLP-1 receptors in the brainstem and afferent taste pathways, as well as vagus nerve-related processes.