Report Title

Dark Chocolate (70% Cacao) Modulates Gamma Wave Frequencies in Vigorously Active Individuals

Collective Title

Master of Science in Nutrition and Dietetics Research Reports 2018


Background: Visualization and the demand to increase cognitive function to improve performance is an area of growing interest in athletes and physically active individuals. Gamma (25-45 Hz) waves, the fastest of the brainwave frequencies, are optimal for cognitive function.

Objective: Determine if savoring and ingestion of dark chocolate (70% cacao) can modulate gamma wave frequencies between visualization at a state of rest and a state of exercise performance in vigorously active individuals.

Participants/setting: The study recruited 10 vigorously active individuals from Loma Linda University. Participants’ mean age was 23.7± 2.2 years. Vigorous activity was defined by the Centers for Disease Control and America College of Sports Medicine.

Intervention: Participant visualization of rest and exercise were assessed by EEG Power Spectral Density (PSD) during three 60-second trials: without cacao (1.4 g of 70% cacao) consumption, savoring cacao, and after fully ingesting cacao. EEG wave band activity was recorded from 9 cerebral cortical scalp locations.

Statistical analyses performed: Z-scores, using a reference baseline at visualization or rest without cacao were utilized.

Results: During visualization of rest, there was a significant increase of 541.5% in gamma wave frequency when comparing no cacao to savoring cacao (p=<.001). During exercise visualization, there was a significant increase of 207.5% in gamma wave frequency when comparing no cacao to savoring cacao (p=<.001). Z-score PSD of overall gamma wave frequencies were lowest in the absence of cacao during rest and exercise respectively (.32, .75). During visualization of rest, there was a significant decrease of 58.0% in gamma waves when comparing savoring cacao to fully ingesting cacao (p=<.001).

Conclusions: We suggest that EEG gamma waves are heightened during savoring and ingestion of 1.4 g of cacao, when visualization of rest and exercise take place.

LLU Discipline

Nutrition and Dietetics


Nutrition and Dietetics


School of Allied Health Professions

First Advisor

Hodgkin, Georgia

Second Advisor

Bains, Gurinder

Third Advisor

Dhuri, Sayali

Fourth Advisor

Patel, Krisha

Fifth Advisor

Bradburn, Jessica

Sixth Advisor

Miller, Josh

Seventh Advisor

Bruhjell, Kristen

Eighth Advisor

Berk, Lee

Degree Name

Master of Science (MS)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Athletic Performance/physiology; Cognition/physiology; Gamma Rhythm/physiology; Electroencephalography; Chocolate


dark chocolate, visualization, cognitive function, athletic performance


Research Report

Page Count


Digital Format


Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.


Loma Linda University Research Reports

Collection Website


Loma Linda University. University Libraries.