Well this is exciting, and a great excuse to eat more dark chocolate or cacao nibs as I get older (score!):
Studies have have shown that a diet high in cocoa flavanols increases the neural connections in the dentate gyrus region of the hippocampus, and can reverse age related memory loss.
“In addition to the boost in neuronal connections in the dentate gyrus, memory test scores also improved for those receiving a high level of dietary flavanols… After the three month study, those drinking high levels of flavanols had the working memory of someone decades younger than themselves.”
The article does say that eating a bunch of chocolate is not the best method to ingest these flavanols, and this is kind of how I feel about that news: