Chocolate and the brain: Cacao increases power spectral density (μV2) of EEG gamma wave band activity (31–40Hz) which is associated with neuronal synchronization, enhanced cognition, memory, recall and physiological benefits
Authors: Berk Lee , Lee Jinhyun , Mali Deeti , Lohman Everett , Bains Gurinder , Daher Noha , Bradburn Jessica , Mohite Ronak , Vijayan Nikita , Juneja Savleen , Shah Srishti , Shah Ankit , Shah Pankti 
Published: November 2023

Cacao (dark chocolate) is a major source of flavonoids. Cacao flavonoids are potent antioxidants and anti‐inflammatory components, with known mechanisms beneficial to cardiovascular health. However, the correlates of neuroelectric activities that initiate the mechanisms of cocoa's beneficial effects on brain neurocognition, synchronization, memory, recall, mood and behavior are unknown. Studies have shown that absorbed cocoa flavonoids penetrate and accumulate in brain hippocampal regions involved in learning and memory. Neurobiological correlates of cocoa flavonoids cascade the expression of neuroprotective and neuromodulatory proteins that promote neurogenesis, neuronal function, brain connectivity, blood‐flow improvement and angiogenesis in brain and sensory systems. However, neuroelectric activity initiation and modulatory control of acute action from cacao flavanoids on brain state has remained unknown.

Purpose

The purpose of this study is to provide evidence for cacao initiation of brain state frequency modulation and differentiation (0–40Hz) via electroencephalography (EEG).

Methods

Assessment of EEG Power Spectral Density μV2 (PSD) of 27 subjects during a sequence of cacao cognitive and sensory awareness tasks ranging from: cognition of past experience, imagination of eating, visualization, olfaction, taste, and satiation of cacao consumption (70% cacao bar, Parliament Chocolates, Redlands, CA). EEG wave band activity was recorded from 9 cerebral cortical scalp regions F3, Fz, F4, C3, Cz, C4, P3, Pz, and P4 using the EEG B‐Alert 10X System™, Carlsbad, CA. Second by second nine bandwidth BW for each subject was recorded. The PSD BW values were referenced to the eyes closed baseline task and Z‐scored.

Results

For statistical analysis we used a one‐way repeated ANOVA with Bonferroni adjustment for multiple comparisons. Z‐scores were graphed and analyzed for each task and BW across 0–40 Hz. The overall respective BW were collapsed across all 9 EEG channels. Gamma Band Activity (γBA) (31–40Hz) for PSD was greatest in all 9 brain regions for all 6 sensory tasks (p<0.01). The most profound observation was the composite of sensory tasks PSD for γ BA was highest of all the 5 frequencies (See Graph with Table).

Conclusion

This study provides objective evidence that EEG γBA is initiated by different cacao sensory awareness tasks ranging from cognitive prior conditioned experience to acute cocoa consumption, with subsequent modulation for brain, behavioral and physiological benefits. We propose this protocol as a potential assessment tool in determining the efficacy of cacao dose response modulation of PSD γBA 31–40 Hz for optimization of brain health benefits.

Delta 1~3hz
Theta 3~7hz
Alpha 8~13hz
Beta 13~30hz

Gamma X̄† ± SEM
2.64 ± 0.73 (G) *
2.64 ± 1.02 (G)
2.64 ± 1.26 (G)
2.64 ± 0.61 (G)

D/T/A/B** X̄ ± SEM
1.18 ± 0.73 (D)
0.61 ± 1.02 (T)
0.12 ± 1.26 (A)
1.42 ± 0.61 (B)

X̄ difference
G‐D: 1.46
G‐T: 2.03
G‐A: 2.52
G‐B: 1.22

P‐value
P<0.001
P<0.001
P<0.001
P<0.001

Z‐scored PSD μV2

Gamma 31–40hz

Delta/Theta/Alpha/Beta