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Cognitive and physiological effects of an “energy drink”: an evaluation of the whole drink and of glucose, caffeine and herbal flavouring fractions

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Abstract

Rationale

Both glucose and caffeine can improve aspects of cognitive performance and, in the case of caffeine, mood. There are few studies investigating the effects of the two substances in combination.

Objectives

We assessed the mood, cognitive and physiological effects of a soft drink containing caffeine and glucose as well as flavouring levels of herbal extracts. The effects of different drink fractions were also evaluated.

Methods

Using a randomised, double-blind, balanced, five-way crossover design, 20 participants who were overnight fasted and caffeine-deprived received 250 ml drinks containing 37.5 g glucose; 75 mg caffeine; ginseng and ginkgo biloba at flavouring levels; a whole drink (containing all these substances) or a placebo (vehicle). Participants were assessed in each drink condition, separated by a 7-day wash-out period. Cognitive, psychomotor and mood assessment took place immediately prior to the drink then 30 min thereafter. The primary outcome measures included five aspects of cognitive performance from the Cognitive Drug Research assessment battery. Mood, heart rate and blood glucose levels were also monitored.

Results

Compared with placebo, the whole drink resulted in significantly improved performance on “secondary memory” and “speed of attention” factors. There were no other cognitive or mood effects.

Conclusions

This pattern of results would not be predicted from the effects of glucose and caffeine in isolation, either as seen here or from the literature addressing the effects of the substances in isolation. These data suggest that there is some degree of synergy between the cognition-modulating effects of glucose and caffeine which merits further investigation.

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References

  • Alford C, Cox H, Wescott R (2000) The effects of Red Bull energy drink on human performance and mood. Amino Acids 21:139–150

    Article  Google Scholar 

  • Azari NP (1991) Effects of glucose on memory processes in young adults. Psychopharmacology 105:521–524

    CAS  PubMed  Google Scholar 

  • Benton D, Owens DS, Parker PY (1994) Blood glucose influences memory and attention in young adults. Neuropsychologia 32:595–607

    Article  CAS  PubMed  Google Scholar 

  • Biaggoni I, Paul S, Puckett A, Arzubiaga C (1991) Caffeine and theophylline as adenosine receptor antagonists in humans. J Pharmacol Exp Ther 258:588–593

    PubMed  Google Scholar 

  • Blokland A (1996) Acetylcholine: a neurotransmitter for learning and memory? Brain Res Rev 21:285–300

    Article  Google Scholar 

  • Bond A, Lader M (1974) The use of analogue scales in rating subjective feelings. Br J Psychol 47:211–218

    Google Scholar 

  • Donohoe RT, Benton D (1999) Cognitive functioning is susceptible to the level of blood glucose. Psychopharmacology 145:378–385

    Article  CAS  PubMed  Google Scholar 

  • Folstein M, Folstein SE, McHugh PR (1975) Mini Mental State: a practical method of grading the cognitive state of patients for the clinician. J Psychiatr Resources 12:189

    Article  CAS  Google Scholar 

  • Ford CE, Scholey AB, Ayre G, Wesnes K (2002) The effect of glucose administration and the emotional content of words on heart rate and memory. J Psychopharmacol 16:241–244

    CAS  PubMed  Google Scholar 

  • Foster JK, Lidder PG, Sünram S (1998) Glucose and memory: fractionation of enhancement effects. Psychopharmacology 137:259–270

    Article  CAS  PubMed  Google Scholar 

  • Gold PE (1995) Role of glucose in regulating the brain and cognition. Int J Clin Nutr 61:987–995

    Google Scholar 

  • Green PJ, Kirby R, Suls J (1996) The effects of caffeine on blood pressure and heart rate: a review. Ann Behav Med 18:201–216

    Google Scholar 

  • Hale F, Margen S, Rabak D (1982) Postprandial hypoglycaemia and psychological symptoms. Biol Psychiatry 17:125–130

    CAS  PubMed  Google Scholar 

  • Hayman M (1942) Two minute clinical test for measurement of intellectual impairment in psychiatric disorders. Arch Neurol Psychiatry 47:454–464

    Google Scholar 

  • Hughes JR, Oliveto AH (1997) A systematic survey of caffeine intake in Vermont. Exp Clin Psychopharmacol 5:393–398

    Article  CAS  PubMed  Google Scholar 

  • Kennedy DO, Scholey AB (2000) Glucose administration, heart rate and cognitive performance: effects of increasing mental effort. Psychopharmacology 149:63–71

    Article  CAS  PubMed  Google Scholar 

  • Kennedy DO, Scholey AB (2003) Ginseng: potential in the enhancement of cognitive performance and mood (review). Pharmacol Biochem Behav 75:687–700

    Article  CAS  PubMed  Google Scholar 

  • Kennedy DO, Scholey AB, Wesnes KA (2000) The dose dependent cognitive effects of acute administration of Ginkgo biloba to healthy young volunteers. Psychopharmacology 151:416–423

    Article  CAS  PubMed  Google Scholar 

  • Kennedy DO, Scholey AB, Wesnes KA (2001a) Differential, dose-dependent changes in cognitive performance and mood following acute administration of Ginseng to healthy young volunteers. Nutr Neurosci 4:295–310

    CAS  PubMed  Google Scholar 

  • Kennedy DO, Scholey AB, Wesnes KA (2001b) Differential, dose dependent changes in cognitive performance following acute administration of a Ginkgo biloba/Panax ginseng combination to healthy young volunteers. Nutr Neurosci 4:399–412

    CAS  PubMed  Google Scholar 

  • Kennedy DO, Scholey AB, Tildesley NTJ, Perry EK, Wesnes KA (2002a) Modulation of mood and cognitive performance following acute administration of single doses of Melissa officinalis (lemon balm). Pharmacol Biochem Behav 72:953–964

    Article  CAS  PubMed  Google Scholar 

  • Kennedy DO, Scholey AB, Wesnes KA (2002b) Modulation of cognition and mood following administration of single doses of Ginkgo biloba, Ginseng and a Ginkgo/Ginseng combination to healthy young adults. Physiol Behav 75:1–13

    Article  PubMed  Google Scholar 

  • Kennedy DO, Wake G, Savealev S, Tildesley NTJ, Perry EK, Wake G, Wesnes KA, Scholey AB (2003) Modulation of mood and cognitive performance following administration of single doses of Melissa officinalis (lemon balm) with human CNS nicotinic and muscarinic receptor binding properties. Neuropsychopharmacology 28:1871–1881

    Article  CAS  PubMed  Google Scholar 

  • Keppel G (1991) Design and analysis. Prentice Hall, New Jersey

  • Keul J, Huber G, Lehman M, Berg A, Jakob EF (1982) Einfluss von Dex-trose auf Fahrleistung, Konzentrationsfaehigkeit, Kreislauf und Stoff-wechsel in Kraftfahrzeug-simulator (Doppelblind-studie im Cross-over Design). Akt Ernahr Mad 7:7–14

    Google Scholar 

  • Koelega HS (1998) Effects of caffeine, nicotine and alcohol on vigilance performance. In: Snel J, Lorist M (eds) Nicotine, caffeine and social drinking. OPA, Amsterdam, pp 363–373

  • Korol DL, Gold PE (1998) Glucose, memory, and aging. Am J Clin Nutr 67(Suppl):764–771

    Google Scholar 

  • Lane JD, Phillips-Bute BG (1998) Caffeine deprivation affects vigilance performance and mood. Physiol Behav 65:171–175

    Article  CAS  PubMed  Google Scholar 

  • Loor M, McNair D (1980) Profile of mood states. Educational and Industrial Testing Service, San Diego

  • Martin PY, Benton D (1999) The influence of a glucose drink on a demanding working memory task. Physiol Behav 67:69–74

    Article  CAS  PubMed  Google Scholar 

  • Mathews DR, Holman RR, Bown E, Steenson J, Watson A, Hughes S, Scott D (1987) Pen sized digital 30 s blood glucose meter. Lancet 1:778–779

    Article  PubMed  Google Scholar 

  • Metzer M (2000) Glucose enhancement of a facial recognition task in young adults. Physiol Behav 68:549–553

    Article  PubMed  Google Scholar 

  • Moss MC, Scholey AB, Wesnes KA (1998) Oxygen administration selectively enhances cognitive performance in healthy young adults: a placebo-controlled double-blind crossover study. Psychopharmacology 138:27–33

    Article  CAS  PubMed  Google Scholar 

  • Nehlig A, Boyett S (2000) Dose-response study of caffeine effects on cerebral functional activity with a specific focus on dependence. Brain Res 858:71–77

    Article  CAS  PubMed  Google Scholar 

  • Nehlig A, Daval J, Debry G (1992) Caffeine and the central nervous system: mechanisms of action, biochemical, metabolic and psychostimulant effects. Brain Res Rev 17:139–170

    Article  CAS  PubMed  Google Scholar 

  • Owens DS, Benton D (1994) The impact of raising blood glucose on reaction times. Neuropsychobiology 30:106–113

    CAS  PubMed  Google Scholar 

  • Park CR (2001) Cognitive effects of insulin in the central nervous system (review). Neurosci Biobehav Rev 25:311–323

    Article  CAS  PubMed  Google Scholar 

  • Parsons MW, Gold PE (1992) Glucose enhancement of memory in elderly humans: an inverted-U dose response curve. Neurobiol Aging 13:401–404

    Article  CAS  PubMed  Google Scholar 

  • Passmore AP, Kondowe GB, Johnston GD (1987) Renal and cardiovascular effects of caffeine: a dose response study. Clin Sci 72:749–756

    CAS  PubMed  Google Scholar 

  • Pincomb GA, Wilson MF, Sung BH, Passey RB, Lovallo WR (1991) Effects of caffeine on pressor regulation during rest and exercise in men at risk of hypertension. Am Heart J 122:1107–1125

    Article  CAS  PubMed  Google Scholar 

  • Quinlan PT, Lane J, Aspinall L (1997) Effects of hot tea, coffee and water ingestion on physiological responses and mood: the role of caffeine, water and beverage type. Psychopharmacology 134:164–173

    Article  CAS  PubMed  Google Scholar 

  • Quinlan PT, Lane J, Moore KL, Aspen J, Rycroft JA, O’Brien DC (2000) The acute physiological effects of tea and coffee; the role of caffeine level. Pharmacol Biochem Behav 66:19–28

    Article  CAS  PubMed  Google Scholar 

  • Reid M, Hammersley R (1995) Effects of carbohydrate intake on subsequent food intake and mood state. Physiol Behav 58:421–427

    Article  CAS  PubMed  Google Scholar 

  • Reidel A, Hogervorst E, Leboux R, Verhey F, van Praag H, Jolles J (1995) Caffeine attenuates scopolamine induced memory impairment in humans. Psychopharmacology 122:158–168

    CAS  PubMed  Google Scholar 

  • Reyner LA, Horne JA (2002) Efficacy of a “functional energy drink” in counteracting driver sleepiness. Physiol Behav 75:331–335

    Article  CAS  PubMed  Google Scholar 

  • Rogers PJ, Martin J, Smith C, Heatherley SV, Smit HJ (2003) Absence of reinforcing, mood and psychomotor performance effects of caffeine in habitual non-consumers of caffeine. Psychopharmacology 167:54–62

    CAS  PubMed  Google Scholar 

  • Rusted JM (1988) Dissociative effects of scopolamine on working memory in healthy young volunteers. Psychopharmacology 96:487–492

    CAS  PubMed  Google Scholar 

  • Rusted JM, Warburton DM (1988) Effects of scopolamine on working memory in healthy young volunteers. Psychopharmacology 96:145–152

    CAS  PubMed  Google Scholar 

  • Rusted JM, Warburton DM (1991) Molecules for modelling cognitive impairment. In: Hindmarch I, Hippius H, Wilcox G (eds) Dementia, molecules, methods and measurement. Academic, London

  • Rusted JM, Eaton-Williams P, Warburton DM (1991) A comparison of the effects of scopolamine and diazepam on working memory. Psychopharmacology 105:442–445

    CAS  PubMed  Google Scholar 

  • Scholey AB (2001) Fuel for thought. Psychologist 14:196–201

    Google Scholar 

  • Scholey AB, Fowles K (2002) Retrograde enhancement of kinaesthetic memory by alcohol and by glucose. Neurobiol Learn Mem 78:477–483

    Article  CAS  PubMed  Google Scholar 

  • Scholey AB, Kennedy DO (2002) Acute, dose-dependent cognitive effects of ginkgo biloba, panax ginseng and their combination in healthy young volunteers: differential interactions with cognitive demand. Hum Psychopharmacol Clin Exp 17:35–44

    Article  Google Scholar 

  • Scholey AB, Moss MC, Neave N, Wesnes KA (1999) Cognitive performance, hyperoxia and heart rate following oxygen administration in healthy young adults. Physiol Behav 67:783–789

    Article  CAS  PubMed  Google Scholar 

  • Scholey AB, Harper S, Kennedy DO (2001) Cognitive demand and blood glucose. Physiol Behav 73:585–592

    Article  CAS  PubMed  Google Scholar 

  • Seidl R, Peyrl A, Nicham R, Hauser E (2000) A taurine and caffeine containing drink stimulates cognitive performance and well-being. Amino Acids 19:635–642

    Article  CAS  PubMed  Google Scholar 

  • Smit HJ, Rogers PJ (2002) Effects of “energy” drinks on mood and mental performance: critical methodology. Food Qual Preference 13:317–326

    Article  Google Scholar 

  • Smith AP (2000) Behavioral effects of caffeine. In: Parliament TH, Ho C-T, Schieberle P (eds) Caffeinated beverages: health benefits, physiological effects, and chemistry. Oxford University, New York, pp 30–45

  • Smith A (2002) Effects of caffeine on human behavior. Food Chem Toxicol 40:1243–1255

    Article  CAS  PubMed  Google Scholar 

  • Smith A, Miles C (1986) Effects of lunch on cognitive vigilance tasks. Ergonomics 29:1251–1261

    CAS  PubMed  Google Scholar 

  • Smith A, Rusted JM, Eaton-Williams P, Savory M, Leathwood P (1990) Effects of caffeine given before and after lunch on sustained attention. Neuropsychobiology 23:160–163

    PubMed  Google Scholar 

  • Smith AP, Kendrick AM, Maben AL, Salmon J (1994a) Effects of breakfast and caffeine on performance, mood and cardiovascular functioning. Appetite 22:39–55

    Article  CAS  PubMed  Google Scholar 

  • Smith A, Maben A, Brockman P (1994b) Effects of evening meal and caffeine on cognitive function, mood and cardiovascular functioning. Appetite 22:57–65

    Article  CAS  PubMed  Google Scholar 

  • Smith AP, Clark R, Gallagher J (1999) Breakfast cereal and caffeinated coffee: effects on working memory, attention, mood, and cardiovascular function. Physiol Behav 67:9–17

    Article  CAS  PubMed  Google Scholar 

  • Smith A, Brice C, Nash J, Rich N, Nutt DJ (2003) Caffeine and central noradrenaline: effects on mood, cognitive performance, eye movements and cardiovascular function. J Psychopharmacol 17:283–292

    Article  CAS  PubMed  Google Scholar 

  • Sünram-Lea SI, Foster JK, Durlach P, Perez C (2001) Glucose facilitation of cognitive performance in healthy young adults: examination of the influence of fast-duration, time of day and pre-consumption plasma glucose levels. Psychopharmacology 157:46–54

    Article  PubMed  Google Scholar 

  • Sünram-Lea SI, Foster JK, Durlach P, Perez C (2002) Investigation into the significance of task difficulty and divided allocation of resources on the glucose memory facilitation effect. Psychopharmacology 160:387–397

    Article  PubMed  Google Scholar 

  • Taylor LA, Rachman SJ (1987) The effects of blood sugar levels changes on cognitive function, affective state and somatic symptoms. J Behav Med 20:544–549

    Google Scholar 

  • Warburton DM (1995) The effects of caffeine on cognition and mood without caffeine abstinence. Psychopharmacology 119:66–70

    CAS  PubMed  Google Scholar 

  • Warburton DM, Bersellini E, Sweeney E (2001) An evaluation of a caffeinated taurine drink on mood, memory and information processing in healthy volunteers without caffeine abstinence. Psychopharmacology 158:322–328

    Article  CAS  PubMed  Google Scholar 

  • Wenk GL (1989) An hypothesis of the role of glucose in the mechanism of cognitive enhancers. Psychopharmacology 99:431–438

    CAS  PubMed  Google Scholar 

  • Weschler D (1958) The measurement and appraisal of human intelligence, 4th edn. Williams & Wilkins, Baltimore

  • Wesnes KA, Ward T, McGinty A, Petrini O (2000) The memory enhancing effects of a Ginkgo-biloba/Panax ginseng combination in healthy middle aged volunteers. Psychopharmacology 152:353–361

    Article  CAS  PubMed  Google Scholar 

Download references

Acknowledgements

This work was funded by GlaxoSmithKline Consumer Healthcare R&D, Slough, UK. The authors are grateful to the anonymous reviewers for their positive and helpful comments.

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Correspondence to Andrew B. Scholey.

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Scholey, A.B., Kennedy, D.O. Cognitive and physiological effects of an “energy drink”: an evaluation of the whole drink and of glucose, caffeine and herbal flavouring fractions. Psychopharmacology 176, 320–330 (2004). https://doi.org/10.1007/s00213-004-1935-2

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  • DOI: https://doi.org/10.1007/s00213-004-1935-2

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