The effects of dark chocolate on cognitive performance during cognitively demanding tasks: A randomized, single-blinded, crossover, dose-comparison study
Akihiro Sasaki,
Kei Mizuno,
Yusuke Morito,
Chisato Oba,
Kentaro Nakamura,
Midori Natsume,
Kyosuke Watanabe,
Emi Yamano,
Yasuyoshi Watanabe
Affiliations
Akihiro Sasaki
Laboratory for Pathophysiological and Health Science, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan; RIKEN Compass to Healthy Life Research Complex Program, Kobe, Japan; Center for Health Science Innovation, Osaka Metropolitan University, Osaka, Japan; Corresponding author. 6-7-3, Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo, 650-0047, Japan.
Kei Mizuno
Laboratory for Pathophysiological and Health Science, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan; RIKEN Compass to Healthy Life Research Complex Program, Kobe, Japan; Center for Health Science Innovation, Osaka Metropolitan University, Osaka, Japan
Yusuke Morito
RIKEN Compass to Healthy Life Research Complex Program, Kobe, Japan
Chisato Oba
Food Microbiology Research Laboratories, R&D Division, Meiji Co., Ltd., Hachioji, Tokyo, Japan
Kentaro Nakamura
Food Microbiology Research Laboratories, R&D Division, Meiji Co., Ltd., Hachioji, Tokyo, Japan
Midori Natsume
Food Microbiology Research Laboratories, R&D Division, Meiji Co., Ltd., Hachioji, Tokyo, Japan
Kyosuke Watanabe
Laboratory for Pathophysiological and Health Science, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan; RIKEN Compass to Healthy Life Research Complex Program, Kobe, Japan; Center for Health Science Innovation, Osaka Metropolitan University, Osaka, Japan
Emi Yamano
Laboratory for Pathophysiological and Health Science, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan; RIKEN Compass to Healthy Life Research Complex Program, Kobe, Japan; Center for Health Science Innovation, Osaka Metropolitan University, Osaka, Japan
Yasuyoshi Watanabe
Laboratory for Pathophysiological and Health Science, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan; RIKEN Compass to Healthy Life Research Complex Program, Kobe, Japan; Center for Health Science Innovation, Osaka Metropolitan University, Osaka, Japan
Dark chocolate, rich in polyphenols, increases cerebral blood flow and improves cognitive function. This study aimed to determine whether the consumption of chocolate with a high concentration of polyphenols helps to maintain cognitive performance during cognitively demanding tasks. In this randomized, single-blinded, crossover, dose-comparison study, 18 middle-aged adults consumed two types of chocolate (25 g each), one with a high concentration (635.0 mg) and the other with a low concentration (211.7 mg) of cacao polyphenols, and performed a cognitive task requiring response inhibition and selective attention over two time periods (15–30 min and 40–55 min after consumption, respectively). Autonomic nerve function and subjective feelings, such as fatigue and concentration, were measured before food intake and after the second task to assess the participant's state. The results showed that the average reaction time between the first and second sessions was not significantly different for either high- or low-concentration chocolate consumption. However, the percentage of correct responses was similar in the first (96.7 %) and second (96.8 %) sessions for high-concentration chocolate consumption and significantly lower for low-concentration chocolate consumption in the second (96.4 %) session than in the first session (97.3 %). Autonomic nerve function showed a significant increase in sympathetic nerve activity after the second task with high-concentration chocolate consumption, while subjective feelings showed an increase in mental fatigue for both chocolate types but a significant decrease in concentration only after the second task with low-concentration chocolate consumption. These findings suggest that dark chocolate consumption contributes to the maintenance of performance and concentration in continuous and demanding cognitive tasks.
