The compounds, called flavanols, were taken in a specially-prepared cocoa drink, according to an experiment published by the journal Nature Neuroscience. Over three months, 37 healthy volunteers aged 50-69 had a daily drink containing either a high dose of flavanols — 900 milligrammes — or a low dose, 10mg. The scientists carried out brain imaging, measuring blood volume in a key part of the hippocampus called the dentate gyrus, a region of memory formation whose performance typically declines as one ages. The tests entailed a 20-minute pattern-recognition exercise designed to assess a type of memory controlled by the dentate gyrus.
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