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Abstract:   (572 Views)
Introduction:­­People mainly have a major interest in eating some palatable foods such as chocolate and sweet foods that influence brain functions. This study investigated the effects of acute, sub-chronic and chronic chocolate consumption with different percent of cocoa/sugar on learning, memory, memory consolidation and electroencephalogram (EEG) waves in rats.   Methods:­­­Thirty-five male Wistar rats were allocated to five main groups containing control and sucrose as well as  dark, milk and white chocolate groups. All groups were freely fed with chow, different kinds of chocolate and sucrose separately for 1,­7 and 14­­days as acute, sub-chronic and chronic food consumption. Also, memory and memory consolidation were evaluated using a passive avoidance test on days 1,7 and 14. In addition, brain electrical activity was evaluated by EEG.
Results:­Acute and sub-chronic dark and milk chocolate consumption significantly improved latency after day 1­ and particularly day 7­. In addition, only the chronic dark chocolate diet showed a significant enhancement in latency after 14­days. White chocolate and sucrose diets did not have significant effects on three latencies. The milk and dark chocolate diets changed nearly all brain waves of EEG, while the sucrose diet did not affect any of them.
Conclusion:­­Unlike sucrose and white chocolate, dark chocolate (acute, sub-chronic and chronic consumption) and milk chocolates (acute and sub-chronic consumption) had beneficial effects on memory and nearly all electrical brain activity probably due to high levels of cocoa and perhaps its antioxidant effect. Hence, these types of diets modified brain homeostasis and increased conscious state and relaxation reduction.
Keywords: chocolate, memory, EEG, sugar, rats.

1. Abbott KN, Arnott CK, Westbrook RF, Tran DM. The effect of high fat, high sugar, and combined high fat-high sugar diets on spatial learning and memory in rodents: A meta-analysis. Neurosci Biobehav Rev 2019; 107: 399-421. [DOI:10.1016/j.neubiorev.2019.08.010]
2. Altermann Torre V, Machado AG, de Sá Couto‐Pereira N, Mar Arcego D, dos Santos Vieira A, Salerno PSV, et al. Consumption of a palatable diet rich in simple sugars during development impairs memory of different degrees of emotionality and changes hippocampal plasticity according to the age of the rats. International Journal of Developmental Neuroscience 2020; 80: 354-368. [DOI:10.1002/jdn.10032]
3. Appleton N. 146 reasons why sugar is ruining your health. Antibiotics to treat rheumatoid arthritis, scleroderma, lupus , juvenile rheumatoid arthritis, polymyositis , dermatomyositis, psoriatic arthritis, reiter's syndrome, ankylosing spondylitis 2011; 8: 1-11.
4. Avena NM, Rada P, Hoebel BG. Evidence for sugar addiction: behavioral and neurochemical effects of intermittent, excessive sugar intake. Neurosci Biobehav Rev 2008; 32: 20-39. [DOI:10.1016/j.neubiorev.2007.04.019]
5. Beilharz JE, Maniam J, Morris M. Short-term exposure to a diet high in fat and sugar, or liquid sugar, selectively impairs hippocampal-dependent memory, with differential impacts on inflammation. Behav Brain Res 2016; 306: 1-7. [DOI:10.1016/j.bbr.2016.03.018]
6. Berk L, Lohman E, Bains G, Bruhjell K, Bradburn J, Vijayan N, et al. Is Chocolate Beneficial for Brain Health? Dark Chocolate (70% Cacao) Increases Brain EEG Power Spectral Density (μV2) Gamma Wave Frequency (31-40Hz) Which Is Associated with Enhanced Cognitive Processing, Learning, Memory, Recall, Neural Synchrony and Mindfulness Meditation. FASEB J 2017; 31: 636.23-636.23.
7. Berridge KC. 'Liking'and 'wanting'food rewards: brain substrates and roles in eating disorders. Physiol Behav 2009; 97: 537-550. [DOI:10.1016/j.physbeh.2009.02.044]
8. Betsy B. Chocolate and Health. Health; 20: 15.
9. Bidi A, Azekour K, Nasri I, Eddouks M, El bouhali B. Effect of Okra Mono-diet on cognitive and emotional performance of rat. Conference: Nutricion Clinica y Dietetica Hospitalaria 2016; 36: 128-129.
10. Campbell IG. EEG recording and analysis for sleep research. Curr Protoc Neurosci 2009; Chapter 10:Unit10.2. [DOI:10.1002/0471142301.ns1002s49]
11. Chepulis LM, Starkey NJ, Waas JR, Molan PC. The effects of long-term honey, sucrose or sugar-free diets on memory and anxiety in rats. Physiol Behav 2009; 97: 359-368 . [DOI:10.1016/j.physbeh.2009.03.001]
12. Clarke MA. Sugar, cane sugar. Kirk‐Othmer Encyclopedia of Chemical Technology 2000. [DOI:10.1002/0471238961.0301140503120118.a01]
13. Dastgerdi HH, Radahmadi M, Reisi P, Dastgerdi AH. Effect of Crocin, Exercise, and Crocinaccompanied Exercise on Learning and Memory in Rats under Chronic Unpredictable Stress. Adv Biomed Res 2018; 7: 137-147. [DOI:10.4103/abr.abr_153_18]
14. Fernell M, Swinton C, Lukowiak K. Epicatechin, a component of dark chocolate, enhances memory formation if applied during the memory consolidation period. Commun Integr Biol 2016; 9: 816-23. [DOI:10.1080/19420889.2016.1205772]
15. Freeman CR, Zehra A, Ramirez V, Wiers CE, Volkow ND, Wang G-J. Impact of sugar on the body, brain, and behavior. Front Biosci (Schol Ed) 2018; 23: 2255-2266. [DOI:10.2741/4704]
16. Giles GE, Avanzato BF, Mora B, Jurdak NA, Kanarek RB. Sugar intake and expectation effects on cognition and mood. Exp Clin Psychopharmacol 2018; 26: 302. [DOI:10.1037/pha0000182]
17. Greenwood CE, Winocur G. Glucose treatment reduces memory deficits in young adult rats fed high-fat diets. Neurobiol Learn Mem 2001; 75: 179-189. [DOI:10.1006/nlme.2000.3964]
18. Hagihira S. Changes in the electroencephalogram during anaesthesia and their physiological basis. Br J Anaesth 2015; 115: 27-31. [DOI:10.1093/bja/aev212.]
19. Hanslmayr S, Volberg G, Wimber M, Raabe M, Greenlee MW, Bäuml K-HT. The relationship between brain oscillations and BOLD signal during memory formation: a combined EEG-fMRI study. J Neurosci 2011; 31: 15674-15680. [DOI:10.1523/JNEUROSCI.3140-11.2011]
20. Hiluy JC, David IA, Daquer AF, Duchesne M, Volchan E, Appolinario JC. A systematic review of electrophysiological findings in binge-purge eating disorders: a window into brain dynamics. Front Physiol 2021; 12. [DOI:10.3389/fpsyg.2021.619780]
21. Hosseini N, Alaei H, Reisi P, Radahmadi M. The effects of NBM-lesion on synaptic plasticity in rats. Brain Res 2017; 1655: 122-127. [DOI:10.1016/j.brainres.2016.11.013]
22. Jacob R, Fan X, Evans M, Dziura J, Sherwin R. Brain glucose levels are elevated in chronically hyperglycemic diabetic rats: no evidence for protective adaptation by the blood brain barrier. Metab Clin Exp 2002; 51: 1522-1524. [DOI:10.1053/meta.2002.36347]
23. Jalilifar M, Yadollahpour A, Moazedi AA, Ghotbeddin Z. Classifying amygdala kindling stages using quantitative assessments of extracellular recording of EEG in rats. Brain Res Bull 2016; 127: 148-155. [DOI:10.1016/j.brainresbull.2016.09.012]
24. Jurkowlaniec E, Tokarski J, Trojniar W. Effect of unilateral ibotenate lesions of the ventral tegmental area on cortical and hippocampal EEG in freely behaving rats. Acta Neurobiol Exp 2003; 63: 369-376.
25. Kajic I, Wennekers T. Neural Network Model of Semantic Processing in the Remote Associates Test. in Proceedings of the NIPS Workshop on Cognitive Computation 2015. K
26. alantarzadeh E, Radahmadi M, Reisi P. Effects of different dark chocolate diets on memory functions and brain corticosterone levels in rats under chronic stress. J Physiol Pharmacol 2020; 24: 185-196. [DOI:10.32598/ppj.24.3.40]
27. Kaminska K, Rogoz Z. The antidepressant- and anxiolytic-like effects following co-treatment with escitalopram and risperidone in rats. J Physiol Pharmacol 2016; 67: 471-480.
28. Kanoski SE, Zhang Y, Zheng W, Davidson TL. The effects of a high-energy diet on hippocampal function and blood-brain barrier integrity in the rat. J Alzheimers Dis 2010; 21: 207-219. [DOI:10.3233/JAD-2010-091414]
29. Kendig MD. Cognitive and behavioural effects of sugar consumption in rodents. A review. Appetite 2014; 80: 41-54.
30. Kirk IJ, Spriggs MJ, Sumner RL. Human EEG and the mechanisms of memory: investigating long-term potentiation (LTP) in sensory-evoked potentials. J R Soc N Z 2021; 51: 24-40. [DOI:10.1080/03036758.2020.1780274]
31. Knezevic B, Komatsuzaki Y, de Freitas E, Lukowiak K. A flavanoid component of chocolate quickly reverses an imposed memory deficit. J Exp Biol 2016; 219:816-823. [DOI:10.1242/jeb.130765]
32. Kruszewski B, Obiedziński MW. Multivariate analysis of essential elements in raw cocoa and processed chocolate mass materials from three different manufacturers. LWT 2018; 98: 113- 123. [DOI:10.1016/j.lwt.2018.08.030]
33. Labbe D, Martin N, Le Coutre J, Hudry J. Impact of refreshing perception on mood, cognitive performance and brain oscillations: An exploratory study. Food Qual Prefer 2011; 22: 92-100. [DOI:10.1016/j.foodqual.2010.08.002]
34. Lamport DJ, Christodoulou E, Achilleos C. Beneficial Effects of Dark Chocolate for Episodic Memory in Healthy Young Adults: A Parallel-Groups Acute Intervention with a White Chocolate Control. Nutrients 2020; 12: 483. [DOI:10.3390/nu12020483]
35. Martin MA, Goya L, de Pascual-Teresa S. Effect of Cocoa and Cocoa Products on Cognitive Performance in Young Adults. Nutrients 2020; 12. [DOI:10.3390/nu12123691]
36. Meng J, Mundahl J H, Streitz T D, Maile K, Gulachek N S, He J, et al. Effects of soft drinks on resting state EEG and brain-computer interface performance. IEEE Access 2017; 5: 18756- 18764. [DOI:10.1109/ACCESS.2017.2751069]
37. Messier C, Whately K, Liang J, Du L, Puissant D. The effects of a high-fat, high-fructose, and combination diet on learning, weight, and glucose regulation in C57BL/6 mice. Behav Brain Res 2007; 178: 139-145. [DOI:10.1016/j.bbr.2006.12.011]
38. Molteni R, Barnard R, Ying Z, Roberts CK, Gómez-Pinilla F. A high-fat, refined sugar diet reduces hippocampal brain-derived neurotrophic factor, neuronal plasticity, and learning. Neuroscience 2002; 112: 803-814. [DOI:10.1016/S0306-4522(02)00123-9]
39. Montopoli M, Stevens L C, Smith C, Montopoli G, Passino S, Brown S, et al. The acute electrocortical and blood pressure effects of chocolate. NeuroRegulation 2015; 2: 3-3. [DOI:10.15540/nr.2.1.3]
40. Murao S, Yoto A, Yokogoshi H. Effect of smelling green tea on mental status and EEG activity. Int J Affect Eng 2013; 12: 37-43. [DOI:10.5057/ijae.12.37]
41. Ndaro NZ, Wang S-Y. Effects of Fatigue Based on Electroencephalography Signal during Laparoscopic Surgical Simulation. Minim Invasive Surg 2018; 2018. [DOI:10.1155/2018/2389158]
42. Radahmadi M, Hosseini Dastgerdi A, Fallah N, Alaei H. The effects of acute, sub-chronic and chronic psychical stress on the brain electrical activity in male rats. Physiol Pharmacol 2017; 21: 185-192.
43. Rahimi S, Alaei H, Reisi P, Zarrin B, Siahmard Z, Pourshanazari AA. Hydroalcoholic tarooneh extract (Spathe of Phoenix Dactylifera) increased sedative-hypnotic effects and modulated electroencephalography brain waves in anesthetized rats. Adv Biomed Res 2019; 8. [DOI:10.4103/2277-9175.255135]
44. Rajaram S, Jones J, Lee GJ. Plant-Based Dietary Patterns, Plant Foods, and Age-Related Cognitive Decline. Adv Nutr 2019; 10: 422-436. [DOI:10.1093/advances/nmz081]
45. Rendeiro C, Guerreiro J D, Williams C M, Spencer J P. Flavonoids as modulators of memory and learning: molecular interactions resulting in behavioural effects. Proc Nutr Soc 2012; 71: 246-262. [DOI:10.1017/S0029665112000146]
46. Samerphob N, Cheaha D, Issuriya A, Chatpun S, Lertwittayanon W, Jensen O, et al. Changes in neural network connectivity in mice brain following exposures to palatable food. Neurosci Lett 2020; 714: 134542. [DOI:10.1016/j.neulet.2019.134542]
47. Santiago-Rodríguez E, Estrada-Zaldívar B, Zaldívar-Uribe E. Effects of Dark Chocolate Intake on Brain Electrical Oscillations in Healthy People. Foods 2018; 7: 187. [DOI:10.3390/foods7110187]
48. Scholey A, Owen L. Effects of chocolate on cognitive function and mood: a systematic review. Nutr Rev 2013; 71: 665-681. [DOI:10.1111/nure.12065]
49. Serres S, Bezancon E, Franconi J-M, Merle M. Ex vivo analysis of lactate and glucose metabolism in the rat brain under different states of depressed activity. Int J Biol Chem 2004; 279: 47881-47889. [DOI:10.1074/jbc.M409429200]
50. Socci V, Tempesta D, Desideri G, De Gennaro L, Ferrara M. Enhancing Human Cognition with Cocoa Flavonoids. Front Nutr 2017; 4: 19. [DOI:10.3389/fnut.2017.00019]
51. Sokolov A N, Pavlova M A, Klosterhalfen S, Enck P. Chocolate and the brain: neurobiological impact of cocoa flavanols on cognition and behavior. Neurosci Biobehav Rev 2013; 37: 2445- 2453. [DOI:10.1016/j.neubiorev.2013.06.013]
52. Songsamoe S, Saengwong-ngam R, Koomhin P, Matan N. Understanding consumer physiological and emotional responses to food products using electroencephalography (EEG). Trends Food Sci Technol 2019; 93: 167-173. [DOI:10.1016/j.tifs.2019.09.018]
53. Takahashi T, Murata T, Hamada T, Omori M, Kosaka H, Kikuchi M, et al. Changes in EEG and autonomic nervous activity during meditation and their association with personality traits. Int J Psychophysiol 2005; 55: 199-207. [DOI:10.1016/j.ijpsycho.2004.07.004]
54. Tammela LI, Pääkkönen A, Karhunen LJ, Karhu J, Uusitupa MI, Kuikka JT. Brain electrical activity during food presentation in obese binge‐eating women. Clin Physiol Funct Imaging 2010; 30: 135-140. [DOI:10.1111/j.1475-097X.2009.00916.x]
55. Torrico DD, Fuentes S, Viejo CG, Ashman H, Gunaratne NM, Gunaratne TM, et al. Images and chocolate stimuli affect physiological and affective responses of consumers: A crosscultural study. Food Qual Prefer 2018; 65: 60-71. [DOI:10.1016/j.foodqual.2017.11.010]
56. Westover AN, Marangell LB. A cross‐national relationship between sugar consumption and major depression? Depress Anxiety 2002; 16: 118-120. [DOI:10.1002/da.10054]
57. Wexler A, Thibault R. Mind-reading or misleading? Assessing direct-to-consumer Electroencephalography (EEG) devices marketed for wellness and their ethical and regulatory implications. J Cogn Enhanc 2019; 3: 131-137. [DOI:10.1007/s41465-018-0091-2]
58. Whyte AR, Williams CM. Effects of a single dose of a flavonoid-rich blueberry drink on memory in 8 to 10 y old children. Nutrition 2015; 31: 531-534. [DOI:10.1016/j.nut.2014.09.013]
59. Wise RA. Role of brain dopamine in food reward and reinforcement. Philos Trans R Soc Lond B Biol Sci 2006; 361: 1149-1158. [DOI:10.1098/rstb.2006.1854]

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