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.

Conclusion: 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.

Keywords:

• Coffee
• Caffeine
• Autonomic nervous system
• Heart rate variability
• Blood pressure

Acknowledgments

We would like to thank all participants, and Mrs Bärbel Girresch for her helpful assistance.

Disclaimer statements

Contributors FZV and CH designed the study and wrote the protocol. CH carried out the experiments. FZV wrote the first draft of the manuscript. FZV, CH, JFT, JK, CW, and HCD were involved in the analysis and interpretation of the data, assisted in writing the manuscript, carefully revised the manuscript, and approved its final content.

Funding None.

Conflicts of interest None.

Ethics approval The study conformed with guidelines issued in the Declaration of Helsinki, and the Ethics Committee of the Charité University Medical Center Berlin approved the study.