The recent research with cocoa was performed at the Columbia University Medical Center. The test subjects were given drinks of cocoa containing a high flavanol content. Unfortunately, this type of cocoa isn't available in stores. Processing of the cocoa before it's sold to the public removes many of its flavanols.
37 people were involved in the study, which is actually a very small number. The age of these people ranged from 50 to 69. Some of the test subjects were given high flavanol cocoa to drink while the rest were given low flavanol cocoa. The researchers performed brain imaging and memory tests on the subjects at the start and the end of the three month experiment.
At the end of the study, the scientists discovered that the people who had followed a high flavanol diet had significantly improved function in their dentate gyrus. In addition, people who had previously had the memory of an average person of 60 now had the memory of a person of 30 to 40 years of age.
The results of the experiment sound fantastic, but they do need to be repeated with a larger sample size. In addition, it would be great if the general public could obtain the high flavanol cocoa used in the experiment. I would definitely start drinking this if I could get it!