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Flavonoids have positive effects on health, including the nervous system. High flavonoid content can be found in chocolate, especially dark chocolate. Verbal working memory is important for reasoning, language comprehension, planning, and spatial processing. The purpose of this study was to evaluate the effect of a single dose of dark and white chocolate administration on verbal working memory in medical students.
A study of experimental pre-post test design with controls was conducted on 60 students. These were simply randomized into two groups: the first group was supplemented with white chocolate as control, and the second group received dark chocolate, at an identical single dose of 100 g. Working memory was measured with the digit span forwards (DSF) and the digit span backwards (DSB) tests, before, at 1 hour, and at 3 hours after intervention. Independent t and Mann-Whitney tests were used for data analysis.
Scores for DSF and DSB in control and treatment groups were similar at baseline. At 1 hour after dark and white chocolate administration, DSF and DSB scores were not significantly different between the two groups (p=0.832; p=0.683). Supplementation of dark chocolate at 3 hours after intervention significantly increased DSB scores compared to white chocolate (p=0.041), but DSF scores were not significantly different between the two groups (p=0.204).
Dark chocolate as a single dose is capable of improving verbal working memory in students, 3 hours after its consumption. Since cocoa contains multiple bioactive compounds, one approach might be to examine the neurocognitive effects of combinations of potential functional ingredients.
Rendeiro C, Guerreiro JDT, Williams CM, et al. Flavonoids as modulators of memory and learning: molecular interactions resulting in behavioural effects. Proc Nutr Soc 2012;71:246-62.
McShea A, Ramiro-Puig E, Munro SB, et al. Clinical benefit and preservation of flavonols in dark chocolate manufacturing. Nutr Rev 2008; 66:630-41.
Field DT, Williams CM, Butler LT. Consumption of cocoa flavanols results in an acute improvement in visual and cognitive functions. Physiol Behav 2011;103:255-60.
D’Esposito M. From cognitive to neural models of working memory. Phil Trans R Soc B 2007;362:761-72.
Budson AE, Price BH. Memory dysfunction. N Engl J Med 2005;352:692-9.
Alhola P, Polo-Kantola P. Sleep deprivation: impact on cognitive performance. Neuropsychiatr Dis Treat 2007;3:553-67.
Nurk E, Refsum H, Drevon CA, et al. Intake of flavonoid-rich wine, tea, and chocolate by elderly men and women is associated with better cognitive test performance. J Nutr 2009;139:120-7.
Barak O, Tsodyks M. Working models of working memory. Neurobiol 2014;25:20-4.
Groth-Marnat G, Baker S. Digit span as a measure of everyday attention: a study of ecological validity. Percept Mot Skill 2003;97: 1209-18.
Choi HJ, Lee DY, Seo EH, et al. A normative study of the digit span in an educationally diverse elderly population. Psychiatr Investig 2014;11: 39-43
Leung JLM, Lee GTH, Lam YH, et al. The use of the Digit Span Test in screening for cognitive impairment in acute medical inpatients. Int Psychogeriatr 2011;23:1569-74.
Rosenthal EN, Riccio CA, Gsanger KM, et al. Digit span components as predictors of attention problems and executive functioning in children. Arch Clin Neuropsychol 2006;21:131-9.
Sastroasmoro S, Ismail S. Dasar-dasar metodologi penelitian klinis. Edisi 4. Sagung Seto, Jakarta. 2011
Grassi D, Lippi C, Necozione S, et al. Short-term administration of dark chococolate is followed by a significant increase in insulin sensitivity and decrease in blood pressure in healthy persons. Am J Clin Nutr. 2005;81:611-4.
Meng CC, Jalil AMM, Ismail A. Phenolic and theobromine contents of commercial dark, milk and white chocolates on the Malaysian market. Molecules 2009;14:200-9.
Conway ARA, Kane MJ, Bunting MF, et al. Working memory span tasks: a methodological review and user’s guide. Psychonom Bull Rev 2005;12:769-86.
Scholey AB, French SJ, Morris PJ, et al. Consumption of cocoa flavanols results in acute improvements in mood and cognitive performance during sustained mental effort. J Psychopharmacol 2010;24:1505-14.
Mastroiacovo D, Kwik-Uribe C, Grassi D, et al. Cocoa flavanol consumption improves cognitive function, blood pressure control, and metabolic profile in elderly subjects: the Cocoa, Cognition, and Aging (CoCoA) Study-a randomized controlled trial. Am J Clin Nutr 2015;101:538-48.
Corti R, Flammer AJ, Hollenberg NK, et al. Cocoa and cardiovascular health Circulation 2009;119:1433-41.
Agarwal SK. Dark chocolate: a therapeutic food. Med Sci 2013;5:13-5.
Wan Y, Vinson JA, Etherton TD, et al. Effects of cocoa powder and dark chocolate on LDL oxidative susceptibility and prostaglandin concentrations in humans. Am J Clin Nutr 2001; 74:596-602.
Williams RJ, Spencer JPE. Flavonoids, cognition, and dementia: actions, mechanisms, and potential therapeutic utility for Alzheimer disease. Free Radic Biol Med 2012;52:35-45
Fournier LR, Ryan-Borchers TA, Robison LM, et al. The effect of soy milk and isoflavone supplements on cognitive performance in healthy postmenopausal women. J Nutr Health Aging 2007;11:155-64.