In the mid 1970s, psychologist Merrill Elias began tracking the cognitive abilities of more than a thousand people. The goal: to observe the relationship between people's blood pressure and brain performance. There was never an inkling that his research would lead to any sort of discovery about chocolate. And yet, 40 years later, it seems to have done just that. The questionnaire gathered all sorts of information about the dietary habits of the participants, [which] revealed an interesting pattern. We found that people who eat chocolate at least once a week tend to perform better cognitively," said Elias. "It's significant - it touches a number of cognitive domains." The findings ... come largely thanks to the interest of Georgina Crichton, a nutrition researcher. What's going on? Crichton can't say with absolute certainty. Nor can Elias, who says he expected to observe the opposite effect - that chocolate, given its sugar content, would be correlated with stunted rather than enhanced cognitive abilities. But they have a few ideas. Nutrients called cocoa flavanols, which are found naturally in cocoa, and thus chocolate, seem to have a positive effect on people's brains. Chocolate, like both coffee and tea, also has methylxanthines, plant-produced compounds that enhance various bodily functions. A lot of previous research has shown that there are, or at least could be, immediate cognitive benefits from eating chocolate. But rarely, if ever, have researchers been able to observe the impact of habitual chocolate eating on the brain.