Your brain on coffee
Coffee as a health food:
Perhaps most consequential, animal experiments show that caffeine may reshape the biochemical environment inside our brains in ways that could stave off dementia. In a 2012 experiment at the University of Illinois at Urbana-Champaign, mice were briefly starved of oxygen, causing them to lose the ability to form memories. Half of the mice received a dose of caffeine that was the equivalent of several cups of coffee. After they were reoxygenated, the caffeinated mice regained their ability to form new memories 33 percent faster than the uncaffeinated.
Close examination of the animals' brain tissue showed that the caffeine disrupted the action of adenosine, a substance inside cells that usually provides energy, but can become destructive if it leaks out when the cells are injured or under stress. The escaped adenosine can jump-start a biochemical cascade leading to inflammation, which can disrupt the function of neurons, and potentially contribute to neurodegeneration or, in other words, dementia.
http://well.blogs.nytimes.com/2013/06/06/this-is-your-brain-on-coffee/?ref=health