1. As humans age, the neuronal architecture that makes up the memory begins to deteriorate,
with neuronal popula8ons or synap8c connec8ons decreasing over 8me, leaving the systems
less efficient in the processing and storage of sensory informa8on. One of the possible effects
flavonoids have in the brain is an ability to induce the development of new neuronal 8ssue. 7
Flavonoids and their metabolites that reach the brain are thought to exert ac8vity at receptors,
kinases, and transcrip8on factors. 8 More research is needed to determine more precisely
where and how these interac8ons occur, however by affec8ng such pathways they have the
poten8al to induce new protein synthesis in neurons and and an ability to cause physical
changes which have a direct influence on memory acquisi8on, consolida8on and storage. 8
Cogni8on is thought to be improved by increasing and improving cerebral func8on. Epicatechin,
is a type of flavanol that acts on blood vessels in the brain and s8mulates the ac8vity of the
enzyme nitric oxide synthase (NOS), which increases the produc8on of nitric oxide.9 Nitric oxide
is known to increase vasodila8on in local arteries which results in an increase in cerebral blood
flow (CBF).10 In smooth muscle cells like blood vessels, nitric oxide helps to ac8vate the enzyme
guanylate cyclase leading to the conversion of guanosine 5’-triphosphate (GTP) to cyclic
guanosine 3’,5’-monophosphate (cGMP) which induces smooth muscle relaxa8on and therefore
vasodila8on of local arteries.5,11 For op8mal brain func8oning, CBF needs to be well maintained
to support constant oxygen and glucose supply to neurons as well as waste excre8on. Increase
in CBF represents a poten8al means to improve cerebral func8on. 12
Cocoa Flavonoid Consump0on and the Effects on Short-Term MemoryLaurenHebert,RachelMostek,andJakeReinbold
DepartmentofFoodScience&HumanNutri0on,ColoradoStateUniversity,FortCollins,CO
Spring 2016
Abstract: Physiological Aspects:
Objec8ves:
Related Nutri8on: References:
Applica8ons/Conclusions:
Flavonoids in cocoa have been shown to have beneficial effects to the human
brain. Research suggests that the consump8on of dark chocolate can increase
short term memory in which flavonoids can increase and improve cerebral
func8on. Studies have suggested that by maintaining cerebral blood flow by
processes of relaxa8on and conversion of phosphates, improved cerebral
func8on has been shown. The purpose of this research is to conclude how the
substances in dark chocolate affect the human brain and its effects on short
term memory.
Introduc8on:
• According to the USDA, a 100 gram bar of dark chocolate contains about 55
milligrams of flavonoids.13
• In order to see an improvement short-term memory, one study has shown that
250 mg of flavonoids would have to be consumed to induce significant
vasodilla8on.14
• To consume 250 mg of flavonoids in the form of dark chocolate, a person would
have to consume approximately 1 pound of dark chocolate per day.
• To conclude, the benefits the flavonoids would have on cogni8on likely do not
outweigh the risks because 1 pound of chocolate would possibly lead to other
nega8ve health consequences.
• More research is needed to determine if flavonoid supplements can be used as
an alterna8ve.14
• Ea8ng a variety of flavonoid containing foods, aside from just chocolate, is likely
the healthiest way to ensure adequate intake.
Another reason chocolate has been thought to increase cogni8on is because
of its s8mulant effects. Chocolate ocen contains caffeine, which could play a
role, but another substance that has been shown to have a s8mula8ng
effect is theobromine.
1. Pase M, Scholey A, Pipingas A, Kras M, Nolidin K, Gibbs A, Wesnes K, Stough C. Cocoa polyphenols enhance posi8ve mood states but not cogni8ve
performance: a randomized, placebo-controlled trial. Psychopharm. 2013; 27(5): 451-458. doi: 10.1177/0269881112473791
2. Prastowo NA, Kristanto S, Sasmita PK. Dark chocolate administra8on improves working memory in students. Universa Medicina. 2015;34:229-236.
3. Knezevic B, Komatsuzaki Y, Freitas E, Lukowiak K. A flavanoid component of chocolate quickly reverses an imposed memory deficit. J Exp Biol. 2016. doi:
10.1242/jeb.130765
4. Smit H, Gaffan E, Rogers P. Methylxanthines are the psycho-pharmacologically ac8ve cons8tuents of Chocolate. Physchopharmacology. 2004; 176:
412-419. Doi: 10.1007/s00213-004-1898-3
5. Nehlig A. The neuroprotec8ve effects of cocoa flavanol and its influence on cogni8ve performance. Br. J. Clin. Pharmacol. 2013; 75, 716-727. 10.1111/j.
1365-2125.2012.04378.x
6. Ruxton, C. H. S. (2008), The impact of caffeine on mood, cogni8ve func8on, performance and hydra8on: a review of benefits and risks. Nutri8on Bulle8n,
33: 15–25. doi: 10.1111/j.1467-3010.2007.00665.x
7. Food for thought: the role of dietary flavonoids in enhancing human memory, learning and neuro-cogni8ve performance. Spencer JP Proc Nutr Soc. 2008
May; 67(2):238-52
8. Spencer JPE. Flavonoids and brain health: mul8ple effects underpinned by common mechanisms. Genes Nutr.2009 Dec; 4(4):243-250. Doi: 10.1007/
s12263-009-0136-3
9. Drake CT, Iadecola C. The role of neuronal signaling in controlling cerebral blood flow. Brain and Language. 2006; I02:141-152. Doi: 10.1016/j.bandI.
2006.08.002
10. Piknova B, Kocharyan A, Schechter AN, Silva AC; The role of nitrite in neurovascular coupling. Brain Research. 2011; 1407: 62-68. Doi: 10.1016/j.brainres.
2011.06.045
11. Klabunde R. Nitric Oxide. Cardiovascular Physiology Concepts Web site. hlp://www.cvphysiology.com/Blood%20Flow/BF011.htm. Published: 1998.
Updated 2008. Accessed: April 2, 2016.
12. Duman RS, Nestler EJ. Guanylyl Cyclase. In: Siegal GJ, Agranoff BW, Albers RW, et al., editors. Basic Neurochemistry: Molecular, Cellular and Medical
Aspects. 6th edi8on. Philadelphia: Lippincol-Raven; 1999. Available from: hlp://www.ncbi.nlm.nih.gov/books/NBK28167/
13. USDA Database for the Flavonoid Content of Selected Foods, Release 3.0. U.S. Department of Agriculture, Agricultural Research Service. hlp://
www.ars.usda.gov/SP2UserFiles/Place/80400525/Data/Flav/Flav_R03.pdf. 2011.
14. Egert S, Rimbach G. Which sources of flavonoids: complex diets or dietary supplements? Advances in NutriAon. 2011; 7(2): 8-14. doi: 10.3945/an.
110.000026
15. Massee L, Ried K, Pase M, et al. The acute and sub-chronic effects of cocoa flavanols on mood, cogni8ve and cardiovascular health in young healthy
adults: a randomized, controlled trail. FronAers in Pharmacology. 2015; 93(6): 1-14. doi: 10.3389/fphar.2015.00093
16. Sorond FA, Hurwitz S, Salat DH, Greve DN, Fisher NDL. Neurovascular coupling, cerebral white maler integrity, and response to cocoa in older people.
Neurology. 2013;81:904-909.
17. Mastroiacovo D, Kwik-Uribe C, Grassi D, et al. Cocoa flavanol consump8on improves cogni8ve func8on, blood pressure control, and metabolic profile in
elderly subjects: the Cocoa, Cogni8on, and Aging (CoCoA) Study--a randomized controlled trial. Am J Clin Nutr. 2015;101:538-48. doi: 10.3945/ajcn.
114.092189.
18. Prastowo NA, Kristanto S, Sasmita PK. Dark chocolate administra8on improves working memory in students. Universa Medicina. 2015;34:229-236.
19. Field D, Williams C, Butler L. Consump8on of cocoa flavanols results in an acute improvement in visual and cogni8ve func8ons. Elsevier. 2011; ?? :255-260.
doi: 10.1016/j.physbeh.2011.02.013
20. Pase M, Scholey A, Pipingas A, Kras M, Nolidin K, Gibbs A, Wesnes K, Stough C. Cocoa polyphenols enhance posi8ve mood states but not cogni8ve
performance: a randomized, placebo-controlled trial. Psychopharm. 2013; 27(5): 451-458. doi: 10.1177/0269881112473791
21. Camfield, D. Scholey, A. Pipingas, A. Silberstein A. Kras, M. Nolidin, K. Wesnes, K. Pase, M. Stough, C. Steady State Visually Evoked Poten8al (SSVEP)
Topography Changes Associated with Cocoa Flavanol Consump8on. Journal of Physiology and Behavior. 2012; 105: 948-957. DOI: 10.1016/j.physbeh.
2011.11.013
• Discuss the rela8onship between cocoa flavonoids and cogni8on
• Differen8ate between the effects of caffeine and theobromine on cogni8on
• Explain physiological effects cocoa flavonoids have on increasing
vasodila8on in the brain
Flavonoids are compounds that are a class of polyphenols which are
tradi8onally found in plants. 1 Flavanols are a subcategory of flavanoids. These
flavonoids can be found in common food sources such as dark chocolate.
Specifically, epicatechin is a flavanol that can be found in dark chocolate made
from Theobroma cacao or cacao beans. 2 Epicatechin can have physiological
consequences on the brain which could possibly lead to an increase in short-
term memory. 3
Epicatechin
GTP
Nitric Oxide
Nitric Oxide
Synthase
cGMP
Smooth
muscle cell
relaxa8on
Vasodilla8on
Guanylate
cyclase
Future Research:
Numerous studies have been done on the effects of flavonoids in dark
chocolate and how it affects the human brain. Only a few studies showed that
the flavonoids in dark chocolate improved short-term memory. 5 More studies
should be conducted on the correla8on between short-term memory and
flavonoids specifically. Numerous studies did show that flavonoids improved
calmness and contentedness, increased reac8on 8me, increased working
memory, or a decrease in mental fa8gue.15-21 These alterna8ve effects could
possibly lead to improvements in short-term memory but more research is
needed to determine if this is the case.
Caffeine:
• Found in small amounts in cocoa beans (50 g bar of dark chocolate
17-36 mg)4
• Effects of caffeine are more established than theobromine5
• Numerous studies showed when caffeine was consumed 75-150 mg
then there was improvement in memory6
Theobromine:
• Found in high amounts in cocoa beans (50 g bar of dark chocolate
237-519 mg) 4
• Metabolite of caffeine
• Has lille effects on the central nervous system5
• Too few studies have been done to conclude any effects on cogni8on6