Thromb Haemost 2014; 112(06): 1151-1158
DOI: 10.1160/th14-05-0450
Blood Coagulation, Fibrinolysis and Cellular Haemostasis
Schattauer GmbH

Effects of dark chocolate consumption on the prothrombotic response to acute psychosocial stress in healthy men

Roland von Känel
1   Department of Neurology, Inselspital, Bern University Hospital, and University of Bern, Switzerland
2   Department of Clinical Research, University of Bern, Switzerland
3   Department of Psychosomatic Medicine, Clinic Barmelweid, Barmelweid, Switzerland
,
Rebecca E. Meister
1   Department of Neurology, Inselspital, Bern University Hospital, and University of Bern, Switzerland
2   Department of Clinical Research, University of Bern, Switzerland
4   Clinical Psychology and Psychotherapy, Psychological Institute, University of Zurich, Switzerland
,
Monika Stutz
5   Thrombosis Research Laboratory, Inselspital, Bern University Hospital, Switzerland
,
Petra Kummer
4   Clinical Psychology and Psychotherapy, Psychological Institute, University of Zurich, Switzerland
,
Angela Arpagaus
4   Clinical Psychology and Psychotherapy, Psychological Institute, University of Zurich, Switzerland
,
Susanne Huber
4   Clinical Psychology and Psychotherapy, Psychological Institute, University of Zurich, Switzerland
,
Ulrike Ehlert
4   Clinical Psychology and Psychotherapy, Psychological Institute, University of Zurich, Switzerland
,
Petra H. Wirtz
6   Biological and Health Psychology, Department of Psychology, University of Bern, Switzerland
7   Work and Health Psychology, University of Konstanz, Konstanz, Germany
› Author Affiliations

Financial support: This work was funded by research grants from the Swiss Cocoa and Chocolate Foundation (Grant 2009) and the Swiss National Science Foundation (Grant PP00P1_128565/1) (both to PHW). The funding bodies had no influence on the study design, data collection and analyses, the writing of the manuscript, or the decision to submit the manuscript for publication.
Further Information

Publication History

Received: 21 May 2014

Accepted after major revision: 22 July 2014

Publication Date:
18 November 2017 (online)

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Summary

Flavanoid-rich dark chocolate consumption benefits cardiovascular health, but underlying mechanisms are elusive. We investigated the acute effect of dark chocolate on the reactivity of prothrombotic measures to psychosocial stress. Healthy men aged 20–50 years (mean ± SD: 35.7 ± 8.8) were assigned to a single serving of either 50 g of flavonoid-rich dark chocolate (n=31) or 50 g of optically identical flavonoid-free placebo chocolate (n=34). Two hours after chocolate consumption, both groups underwent an acute standardised psychosocial stress task combining public speaking and mental arithmetic. We determined plasma levels of four stress-responsive prothrombotic measures (i. e., fibrinogen, clotting factor VIII activity, von Willebrand Factor antigen, fibrin D-dimer) prior to chocolate consumption, immediately before and after stress, and at 10 minutes and 20 minutes after stress cessation. We also measured the flavonoid epicatechin, and the catecholamines epinephrine and norepinephrine in plasma. The dark chocolate group showed a significantly attenuated stress reactivity of the hypercoagulability marker D-dimer (F=3.87, p=0.017) relative to the placebo chocolate group. Moreover, the blunted D-dimer stress reactivity related to higher plasma levels of the flavonoid epicatechin assessed before stress (F=3.32, p = 0.031) but not to stress-induced changes in catecholamines (p’s=0.35). There were no significant group differences in the other coagulation measures (p’s≥0.87). Adjustments for covariates did not alter these findings. In conclusion, our findings indicate that a single consumption of flavonoid- rich dark chocolate blunted the acute prothrombotic response to psychosocial stress, thereby perhaps mitigating the risk of acute coronary syndromes triggered by emotional stress.