title: Short-term effects of espresso coffee on heart rate variability and blood pressure in habitual and non-habitual coffee consumers--a randomized crossover study.
abstract: OBJECTIVE
  Coffee is one of the most widely consumed beverages worldwide. Aim of this study was to investigate short-term effects of espresso coffee on heart rate variability (HRV), a marker of vagal activity, in healthy habitual and non-habitual coffee consumers.
  
  
  METHODS
  Seventy-seven healthy subjects (38 habitual and 39 non-habitual coffee consumers, 74% women, mean age 26.97 ± 6.88 years) took part in three laboratory sessions in a randomized order. In condition 1, subjects consumed espresso; in condition 2, subjects consumed decaffeinated espresso; and in condition 3, subjects consumed warm water. HRV and blood pressure were assessed at rest before and after ingestion of the respective beverage.
  
  
  RESULTS
  HRV was significantly increased after consumption of caffeinated espresso, decaffeinated espresso, or water, indicating increased vagal activity in the course of the experiments. In the habitual coffee consumers, the increase in vagally mediated HRV was significantly lower after consumption of decaffeinated espresso compared to caffeinated espresso. Increases of systolic blood pressure were only found in the non-habitual consumers.
  
  
  CONCLUSIONS
  We found no evidence for specific short-term effects of caffeinated espresso on vagal activity in healthy subjects. Instead, consumption of decaffeinated espresso inhibited vagal activity in habitual consumers. This may be explained by an attempt of the organism to establish a sympathovagal equilibrium comparable to that after caffeine consumption. In the absence of caffeine-induced sympathetic activation, this may have been achieved by relative vagal withdrawal.
authors: a Department of Psychiatry and Psychotherapy , Charité University Medical Center , Berlin , Germany.|b Department of Psychosomatic Medicine and Psychotherapy , Charité University Medical Center , Berlin , Germany.
authors: Frank
authors: F
authors: Zimmermann-Viehoff
authors: c Department of Psychology , Ohio State University , Columbus , USA.
authors: Julian
authors: J
authors: Thayer
authors: c Department of Psychology , Ohio State University , Columbus , USA.
authors: Julian
authors: J
authors: Koenig
authors: b Department of Psychosomatic Medicine and Psychotherapy , Charité University Medical Center , Berlin , Germany.
authors: Christian
authors: C
authors: Herrmann
authors: b Department of Psychosomatic Medicine and Psychotherapy , Charité University Medical Center , Berlin , Germany.
authors: Cora S
authors: CS
authors: Weber
authors: b Department of Psychosomatic Medicine and Psychotherapy , Charité University Medical Center , Berlin , Germany.
authors: Hans-Christian
authors: HC
authors: Deter
mesh_terms: D000328:Adult; D001341:Autonomic Nervous System / Q000502:physiology* / Q000503:physiopathology; D015415:Biomarkers; D001794:Blood Pressure; D002110:Caffeine / Q000009:adverse effects*; D003069:Coffee / Q000009:adverse effects*; D003296:Cooking; D018592:Cross-Over Studies; D005247:Feeding Behavior; D005260:Female; D005518:Food Preferences; D005858:Germany / Q000453:epidemiology; D006184:Habits; D006339:Heart Rate; D006801:Humans; D006973:Hypertension / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D012306:Risk; D055815:Young Adult
chemical_list: D015415:Biomarkers; D003069:Coffee; D002110:Caffeine
keywords: Autonomic nervous system; Blood pressure; Caffeine; Coffee; Heart rate variability