title: The immediate and short-term chemosensory impacts of coffee and caffeine on cardiovascular activity.
abstract: The immediate and short-term chemosensory impacts of coffee and caffeine on cardiovascular activity.
  
  
  BACKGROUND
  Caffeine is detected by 5 of the 25 gustatory bitter taste receptors (hTAS2Rs) as well as by intestinal STC-1 cell lines. Thus there is a possibility that caffeine may elicit reflex autonomic responses via chemosensory stimulation.
  
  
  METHODS
  The cardiovascular impacts of double-espresso coffee, regular (130 mg caffeine) and decaffeinated, and encapsulated caffeine (134 mg) were compared with a placebo-control capsule. Measures of four post-ingestion phases were extracted from a continuous recording of cardiovascular parameters and contrasted with pre-ingestion measures. Participants (12 women) were seated in all but the last phase when they were standing.
  
  
  RESULTS
  Both coffees increased heart rate immediately after ingestion by decreasing both the diastolic interval and ejection time. The increases in heart rate following the ingestion of regular coffee extended for 30 min. Encapsulated caffeine decreased arterial compliance and increased diastolic pressure when present in the gut and later in the standing posture.
  
  
  CONCLUSIONS
  These divergent findings indicate that during ingestion the caffeine in coffee can elicit autonomic arousal via the chemosensory stimulation of the gustatory receptors which extends for at least 30 min. In contrast, encapsulated caffeine can stimulate gastrointestinal receptors and elicit vascular responses involving digestion.
  
  
  CONCLUSIONS
  Research findings on caffeine are not directly applicable to coffee and vice versa. The increase of heart rate resulting from coffee drinking is a plausible pharmacological explanation for the observation that coffee increases risk for coronary heart disease in the hour after ingestion.
authors: School of Life Sciences, University of Westminster, London, UK. research@micmcmullen.se
authors: Michael K
authors: MK
authors: McMullen
authors: Julie M
authors: JM
authors: Whitehouse
authors: Gillian
authors: G
authors: Shine
authors: Peter A
authors: PA
authors: Whitton
authors: Anthony
authors: A
authors: Towell
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D002110:Caffeine / Q000008:administration & dosage / Q000494:pharmacology*; D002319:Cardiovascular System / Q000187:drug effects; D003069:Coffee; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D007422:Intestines / Q000187:drug effects / Q000502:physiology; D008875:Middle Aged; D011984:Sensory Receptor Cells / Q000187:drug effects / Q000502:physiology
chemical_list: D003069:Coffee; D002110:Caffeine