Effects of chocolate on cognitive function in healthy adults: A systematic review and meta-analysis on clinical trials.

Cognitive function is defined as performance in objective tasks that need conscious mind effort. It has been shown that consuming foods rich in flavanols causes neurobiological effects and improves learning, memory, and global cognitive function. This study aimed to investigate the impact of chronic chocolate consumption on cognitive function in healthy adults based on published trials. The PICO strategy was applied to examine the research question in this study. Researchers searched the Web of Science, Science Direct, Pubmed, Scopus, Cochrane Library, and Google Scholar databases. Related articles of randomized controlled trials that evaluated the chronic effect of chocolate on cognitive function were selected (all published from their inception to February 2021). The difference in means of the last and first measurements was the main effect measure between the control and intervention groups. For quantitative data synthesis, weighted mean difference (WMD) and 95% confidence interval (CI) were performed in the random effect model. Of the initial 340 articles identified, seven trials met the eligibility criteria. Chronic chocolate intake significantly reduced executive function time (WMD: -11.77, 95% CI: -22.49, -1.05, p = 0.03) of the participants. Further, the language and executive function (WMD: 6.38, 95% CI: 5.97, 6.80, p < 0.001) was raised by 6.38 times after the intervention with chocolate. We could not perform subgroup analysis due to insufficient trials and significant heterogeneity in some studies. It is concluded that daily consumption of cocoa may provide short and middle-term effects on young adults and make them better cognitive performance in learning, memory, and attention.