Dark chocolate consumption appears to have beneficial effects on human health by enhancing cognitive function

In November 2019 researchers from Japan published the results of their study to assess the effect of dark chocolate on cognitive function and neurotrophins. Neurotrophins are small proteins that secrete into the nervous system to help keep nerve cells alive. A total of 18 healthy adults, aged 20-31 years, were divided into two groups, with 10 individuals receiving dark chocolate and 8 individuals a cacao-free white chocolate daily for a period of 30 days. Blood samples were taken to measure theobromine (a methylxanthine most often present in dark chocolate), nerve growth factor and brain-derived neurotrophic factor. Cognitive function was also assessed using a modified Stroop colour word test and digital cancellation test, with the prefrontal cerebral blood flow being measured during the tests. (The Stroop test is a demonstration of cognitive interference ie there is a delay in the reaction time to a task due to a mismatch in stimuli, eg the word “red” is printed in blue ink instead of red ink and when asked to name the colour of the word it takes longer and there are more mistakes due to the colour of the ink not matching the name of the colour.) Results showed that the dark chocolate increased the nerve growth factor and theobromine levels, which improved cognitive function performance in both tests. Interestingly, the dark chocolate-mediated improvement in cognitive function was observed three weeks after the end of the chocolate intake. White chocolate consumption did not affect the nerve growth factor and theobromine levels or cognitive performance. These results suggest that dark chocolate consumption has beneficial effects on human health by enhancing cognitive function.

Sumiyoshi E et al. Sub-Chronic Consumption of Dark Chocolate Enhances Cognitive Function and Releases Nerve Growth Factors: A Parallel-Group Randomized Trial. Nutrients. 2019 Nov 16;11(11). pii: E2800.

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