Dark chocolate studies does not come close to suggesting it improves cognition. Only 10 people involved and one study was not published.

Health Headlines Commentary for April 30, 2018

Source:

Dark chocolate may give your brain a boost, studies suggest

Reference:

Dark chocolate (70% organic cacao) increases acute and chronic EEG power spectral density (μV2) response of gamma frequency (25–40 Hz) for brain health: enhancement of neuroplasticity, neural synchrony, cognitive processing, learning, memory, recall, and mindfulness meditation

No full text for this study:

Dark chocolate (70% cacao) effects human gene expression: Cacao regulates cellular immune response, neural signaling, and sensory perception

Analysis:

Dark chocolate and health: Fudging the evidence with USA Today

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