Scientists at Columbia University Medical Center (CUMC) published the results of a dietary experiment, based on the effects of flavanols, extracted from cocoa beans, on the aging human brain in the journal Nature Neuroscience on Sunday.
A group of 37 healthy volunteers aged from 50 to 69 was randomly divided in two. Each day for three months, they had a specially-prepared cocoa drink, which is not available commercially. One group consumed the drink with 900mg of flavanols, and the other with only 10mg of these compounds.
"If a participant had the memory of a typical 60-year-old at the beginning of the study, after three months that person on average had the memory of a typical 30- or 40-year-old," said senior author Scott Small in a press-release.
"I suppose that our study does show, for the first time, that flavanols improves the function of humans' dentate gyrus, particularly in ageing humans," Small told AFP.
To demonstrate the difference before and after the experiment, the participants had to pass special memory tests – a 20-minute pattern-recognition exercise, specifically addressing the dentate gyrus. Faster and clearer recognition among the high-flavanol group was backed by their better blood volume tests.
"When we imaged our research subjects' brains, we found noticeable improvements in the function of the dentate gyrus in those who consumed the high-cocoa-flavanol drink," said lead author Adam M. Brickman, PhD, of the Taub Institute in a press release.
"Very simply, the amount of flavanols that are found in chocolate is minuscule compared to the very high amount of extracted flavanols that our subjects consumed. The same is true for most other foods or teas," Small wrote.
The research was supported by a large US food corporation, which took the responsibility for extracting and preparing the drink in such a way so that it is not lost from the raw plant.
Apart from cocoa and chocolate, flavanols are abundant in some teas, vegetables and fruit – such as grapes, apples or blueberries, but their types vary widely. They are also believed to improve cardiovascular health – to prevent heart attacks and strokes.
Cognitive neuropsychologist Dr. Ashok Jansari told the Independent: “Given a globally ageing population, by isolating a particular area of the brain that is weakening in functioning as we grow older, and demonstrating that a non-pharmacological intervention can improve learning of new information, the authors have made a significant contribution to helping us improve our cognitive health.”