title: Caffeine ingested under natural conditions does not alter taste intensity.
abstract: It has been reported that prolonged application of 10 micromolar (microM) caffeine (CAF) to the dorsal surface of the tongue may markedly enhance the perceived intensity of many taste stimuli, including NaCl and several noncarbohydrate sweeteners. The present study investigated the effect of oral CAF vs. placebo ingestion on perceived taste intensity. Ingestion of CAF (5.5 mg/kg) raised median salivary CAF levels to 19.8 microM at 50 minutes post-dose, when subjects evaluated the intensity of solutions of 5 noncarbohydrate sweeteners, 2 carbohydrate sweeteners, 2 bitter tastants, NaCl, citric acid, 2 odors, and a tone. Taste solutions were prepared using either 1) deionized water or 2) 10 microM CAF as the medium, and all stimuli were rated for intensity on a 9-point category scale. There was no effect of condition (CAF or placebo) or tastant medium on any response measure. The results suggest that perceptions of taste intensity are not appreciably altered under natural conditions of CAF ingestion and subsequent lingual adaptation to microM levels of CAF in saliva.
authors.affiliation: Monell Chemical Senses Center, Philadelphia, PA 19104.
authors.forename: D J
authors.initials: DJ
authors.lastname: Mela
mesh_terms: D000284:Administration, Oral; D000328:Adult; D002110:Caffeine / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008297:Male; D012684:Sensory Thresholds / Q000187:drug effects*; D013649:Taste / Q000187:drug effects*; D014059:Tongue / Q000187:drug effects / Q000502:physiology*
chemical_list: D002110:Caffeine