The Acute Electrocortical and Blood Pressure Effects of Chocolate


  • Michelle Montopoli Department of Psychological Sciences Northern Arizona University
  • Larry C Stevens Department of Psychological Sciences Northern Arizona University
  • Constance Smith Department of Psychological Sciences Northern Arizona University
  • George Montopoli Department of Mathematics Arizona Western College
  • Stephanie Passino Department of Psychological Sciences Northern Arizona University
  • Somer Brown Department of Psychological Sciences Northern Arizona University
  • Lena Camou Department of Psychological Sciences Northern Arizona University
  • Katie Carson Department of Psychological Sciences Northern Arizona University
  • Shannon Maaske Department of Psychological Sciences Northern Arizona University
  • Kathleen Knights Department of Psychological Sciences Northern Arizona University
  • William Gibson Department of Psychological Sciences Northern Arizona University
  • Joyce Wu Department of Psychological Sciences Northern Arizona University



Chocolate, Cocoa, Cacao, L-theanine, EEG, Blood Pressure


Objective: The present study investigated the effects of consuming chocolate on electroencephalograph (EEG) frequencies and localization and on blood pressure.  Method: Across six conditions, 122 participants consumed either higher (60%) cacao chocolate, low (0%) cacao chocolate, higher cacao chocolate +L-theanine, high sugar water, low sugar water, or water.  EEGs, blood pressure, and mood were measured before and after a 60-minute digestion period.  Results: Analyses indicated a decrease in frontal, parietal, and temporal theta and an increase in occipital beta EEG following the consumption of a 60% cacao confection compared with control conditions.  Diastolic blood pressure increased with the consumption of higher cacao chocolate when compared to water alone and to higher cacao chocolate  + L-theanine. Diastolic and systolic blood pressure decreased following consumption of higher cacao + L-theanine chocolate, averaging 4-8 mmHg. No condition-specific mood changes or gender differences were found.  Conclusions: This study suggests an acute stimulating effect of cacao on the human brain and vasoconstrictive effects on peripheral vasculature, the latter of which appear to be offset by an L-theanine additive.  Significance: This is the first known study to investigate acute EEG effects of consuming chocolate and suggests a potential attention-enhancing effect.

Author Biography

Larry C Stevens, Department of Psychological Sciences Northern Arizona University

Department of Psychological Sciences

Northern Arizona University

Full Professor of Psychological Sciences

Licensed Psychologist

National Science Foundation Research Experiences for Undergraduates Site Grant PI and Program Coordinator


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