The randomized, double-blind study by Swinburne University of Technology published in the Journal of Psychopharmacology found that people consuming high cocoa flavanol dark chocolate reported more positive mood states.
Seventy-two healthy men and women aged 40-65 were asked to consumer a 20 g dark chocolate drink mix with either 500 mg of cocoa flavanols, 250 mg or no cocoa flavanols for 30 days.
Participants did not know which type of drink they were consuming.
Each drink mix was dissolved in 200 ml of water. The high dose treatment was Barry Callebaut’s Acticoa cocoa powder, which is produced using a method that preserves flavanols typically lost during production.
Calm and content
The group consuming the most flavanols reported higher levels of calmness and contentedness than other groups after 30 days, but no changes in cognition were observed.
“This randomized controlled trial is perhaps the first to demonstrate the positive effects of cocoa polyphenols on mood in healthy participants,” said the researchers.
“This provides a rationale for exploring whether cocoa polyphenols can ameliorate the symptoms associated with clinical anxiety or depression.”
Mood was assessed using the Bond and Lader Visual analogue Scales, which involved participants measuring their state of mind based on sliding scales on a computer.
A previous study by Scholey (2010), one of the authors of the present study, had found that cocoa flavanols in 994mg and 520 mg doses improved aspects of cognition such as mental arithmetic, but no link was found in this research.
Polyphenols in chocolate
Dark chocolate contains flavonoids, a class of polyphenols, which have been linked to positive health effects such as a reduced risk of cardiovascular disease.
One of chocolate main constituent, cocoa, contains a mixture of polyphonic compounds such as epicatechin and catechin.
According to a 2003 analysis by the US Department of Agriculture (USDA), a typical 100 g bar of dark chocolate contains 41.50 mg of epicatechin and 11.99 mg of catechin.
The same amount of milk chocolate contains an average of 10.45 mg of epicatechin and 2.90 mg of catechin.
Journal of Psychopharmacology , May 2013 vol. 27, no. 5, 451-458
‘Cocoa polyphenols enhance positive mood states but not cognitive performance: A randomized, placebo-controlled trial’
Authors: Pase et al.