Date of Award


Degree Type

Selective Evidence-Based Medicine Review

Degree Name

Master of Science in Health Sciences - Physician Assistant


Physician Assistant Studies

Department Chair

John Cavenagh, MBA, PhD, PA-C


OBJECTIVE: The objective of this selective EBM review is to determine whether or not high-dose cocoa polyphenols are effective in improving emotional states in healthy individuals ages 18-65 years old for long-term treatment.

STUDY DESIGN: Systematic review of two randomized controlled trials (RCTs) and one randomized parallel open-label clinical trial, all published between 2008 and 2013, all English language.

DATA SOURCES: These three studies that evaluate the effectiveness of cocoa polyphenols in emotional state improvement were found using the PubMed database based on their relevance to the clinical question and their inclusion of patient-oriented outcomes.

OUTCOMES MEASURED: These three articles compared changes in mood and emotional states after ingestion of cocoa polyphenols with follow-up self-reported questionnaires and Bond and Lader Visual Analogue Scales (VAS).

RESULTS: Two of the three studies found no significant improvement in mood post-consumption of cocoa polyphenols. Martin et al. demonstrated that consumption of milk chocolate or dark chocolate did not improve mood on subjective questionnaires analyzed by F-scores (p=0.147).11 The Crews et al. study revealed no clinically significant difference (p= .392) in mood between the dark chocolate plus cocoa group and placebo group reported on questionnaires for the duration of six weeks.12 In contrast, the Pase et al. study demonstrated a significant improvement in contentment versus the placebo with consumption of cocoa polyphenols (p<0.05) utilizing comparison of mean values on visual analogue scales (VAS).5

CONCLUSION: There is conflicting data regarding the relationship of cocoa polyphenols and emotional/mood states. The results of two of these studies showed no significant effect comparing mood states before and after consumption of chocolate sources containing cocoa polyphenols for short durations of time under 6 weeks. However, the results of the third study showed that ingestion of cocoa polyphenols for a least 30 days improved contentment. Therefore, it may be possible to improve emotional/mood states in individuals ages 18-65 with cocoa polyphenols when utilized for a longer duration. Consequently, more randomized controlled clinical trials need to be performed to explore this relationship.