Scientific Online Resource System

Varna Medical Forum

Coffee consumption among night and shift workers

Teodora Dimitrova, Darina Hristova, Staniela Porozhanova


Fatigue during day shifts may threaten the health and safety of workers as well as their clients in the service sector. Previous research has proved that caffeine-containing beverages are a reliable method of dealing with exhaustion during day shifts. Although there is plenty of research, the connection between caffeine and safety at the workplace as well as other production indicators of work ability, remains unspecified. The consumption of coffee provided as free food at the workplace of 502 people working overtime or night shifts has been examined.

Most commonly, the people working on day or night shifts consume 2-3 coffees per day. 42,5 % of people working on day shifts and 38,9 % of night workers drink more than 2 coffees daily as a prophylaxis against fatigue. The number of people consuming more than three coffees per day is also high among these groups. 22,5 % of the night workers and 13,9 % of the ones on day shifts drink caffeine-containing beverages dangerously frequently. Working on the night shift (p<0.001) and overtime (p<0.05) is proved to be a risk factor, increasing the frequency of coffee intake.

Caffeine is the world`s most frequently taken pharmacologically active substance. However, evidence of its influence on human health among frequent consumers is still inconclusive.

The consumption of 3-4 cups of coffee daily has proved to stimulate the working ability of adults without threatening their health. This is a reliable prophylaxis against tiredness caused by working on day or night shifts.


кафе; нощен труд

Full Text


Ali A. , J.M. O'Donnell, C. Starck, K.J.Rutherfurd-Markwick, The effect of caffeine ingestion during evening exercise on subsequent sleep quality in females, Int. J. Sports Med., 36 (2015), pp. 433-439

Alles G.A, G.A. FeigenThe influence of benzedrine on work-decrement and patellar reflex, Am. J. Physiol., 136 (1942), pp. 392-400

Brunyé T. T., Mahoney C. R., Lieberman H. R., Giles G. E., Taylor H. A. Acute caffeine consumption enhances the executive control of visual attention in habitual consumers. Brain and Cognition, vol. 74 (3), 2010, 186-192

Çakır Ö. K., Ellek N., Salehin N. et al. Protective effect of low dose caffeine on psychological stress and cognitive function. Physiology & Behavior, Vol. 168, 2017, pp.1-10

Carey MG, Al-Zaiti SS, Dean GE, Sessanna L, Finnell DS. Sleep problems, depression, substance use, social bonding, and quality of life in professional firefighters. J Occup Environ Med. 2011;53(8):928-33

Childs E. , C. Hohoff, J. Deckert, K. Xu, J.Badner, H. deWitAssociation between ADORA2A and DRD2 polymorphisms and caffeine-induced anxiety, Neuropsychopharmacology, 33 (2008), pp. 2791-2800

Clark I., Landolt H. P. Coffee, caffeine, and sleep: A systematic review of epidemiological studies and randomized controlled trials. Sleep Medicine Reviews, Vol 31, 2017, pp. 70-78

Dews P.B. , Caffeine, Annu. Rev. Nutr., 2 (1982), pp. 323-341

Doan BK, Hickey PA, Lieberman HR, Fischer JR. Caffeinated tube food effect on pilot performance during a 9-hour, simulated nighttime U-2 mission. Aviat Space Environ Med.2006;77(10):1034-40

Doepker C. , H.R. Lieberman, A.P. Smith, J.D.Peck, A. El-Sohemy, B.T. Welsh Caffeine: friend or foe? Ann. Rev. Food Sci. Technol., 7 (2016), pp. 117-137

Fulgoni VL, 3rd, Keast DR, Lieberman HR. Trends in intake and sources of caffeine in the diets of US adults: 2001-2010. Am J Clin Nutr. 2015;101(5):1081-87

Glade M. J. Caffeine-Not just a stimulant. Nutrition, Vol 26 (10), 2010, pp. 932-938

Gonzalez deMejia G., Ramirez-Mares M.V. Impact of caffeine and coffee on our health. Trends in Endocrinology and Metabolism,vol 25 (10), 2014, pp. 489-492

Haskell CF, Kennedy DO, Wesnes KA, Scholey AB. Cognitive and mood improvements of caffeine in habitual consumers and habitual non-consumers of caffeine. Psychopharmacology (Berl). 2005;179(4):813-25

Higdon, J.V., Frei, B.Coffee and health: A review of recent human research , 2006 Food Science and Nutrition, 46 (2), pp. 101-123

Jabbar S.B. , M.G. Hanly, Fatal caffeine overdose: a case report and review of literature, Am. J. Forensic Med. Pathol., 34 (2013), pp. 321-324

James JE. Caffeine and cognitive performance: persistent methodological challenges in caffeine research. Pharmacol Biochem Behav. 2014;124:117-22

Kamimori GH, Johnson D, Thorne D, Belenky G. Multiple caffeine doses maintain vigilance during early morning operations. Aviat Space Environ Med. 2005;76(11):1046-50

Kamimori GH, McLellan TM, Tate CM, Voss DM, Niro P, Lieberman HR. Caffeine improves reaction time, vigilance and logical reasoning during extended periods with restricted opportunities for sleep. Psychopharmacology (Berl). 2015;232(12):2031-42

Ker K, Edwards PJ, Felix LM, Blackhall K, Roberts I. Caffeine for the prevention of injuries and errors in shift workers. Cochrane Database Syst Rev. 2010(5):CD008508

Klaassen E. B., Renate H.M. de Groot, Evers E. A.T. et al. The effect of caffeine on working memory load-related brain activation in middle-aged males. Neuropharmacology, Vol 64, 2013, pp.160-167

Knapik JJ, Trone DW, McGraw S, Steelman RA, Austin KG, Lieberman HR. Caffeine use among active duty Navy and Marine Corps personnel. Nutrients. 2016;8(10)

Lieberman HR, Tharion WJ, Shukitt-Hale B, Speckman KL, Tulley R. Effects of caffeine, sleep loss, and stress on cognitive performance and mood during U.S. Navy SEAL training. Sea-Air-Land. Psychopharmacology (Berl). 2002;164(3):250-61

Lorist MM, Snel J, Kok A, Mulder G.Acute effects of caffeine on selective attention and visual search processes. Psychophysiology. 1996 Jul;33(4):354-61

Maridakis V, Herring MP, O'Connor PJ. Sensitivity to change in cognitive performance and mood measures of energy and fatigue in response to differing doses of caffeine or breakfast. Int J Neurosci. 2009;119(7):975-94

McLellan TM, Caldwell JA, Lieberman HR. A review of caffeine's effects on cognitive, physical and occupational performance. Neurosci Biobehav Rev. 2016;71:294-312

McLellan TM, Kamimori GH, Bell DG, Smith IF, Johnson D, Belenky G. Caffeine maintains vigilance and marksmanship in simulated urban operations with sleep deprivation. Aviat Space Environ Med. 2005;76(1):39-45

Mednick S.C., Cai D. J., Kanady J., Drummond S. P. A. Comparing the benefits of caffeine, naps and placebo on verbal, motor and perceptual memory. Behavioural Brain Research, Vol 193 (1) 2008, pp. 79-86

Mitchell DC, Knight CA, Hockenberry J, Teplansky R, Hartman TJ. Beverage caffeine intakes in the U.S. Food Chem Toxicol. 2014;63:136-42

Nawrot P. , S. Jordan, J. Eastwood, J. Rotstein, A. Hugenholtz, M. FeeleyEffects of caffeine on human health, Food Add Contam., 20 (2003), pp. 1-30

Nehlig A. Are we dependent upon coffee and caffeine? A review on human and animal data. Neurosci Biobehav Rev. 1999;23(4):563-76

Nehlig A. Is caffeine a cognitive enhancer? J Alzheimers Dis. 2010;20 1:S85-94

Nguyen-Van-Tam DP (2002) Caffeine and human memory. Ph.D. thesis, University of Cardiff

O'Neill CE, Newsom RJ, Stafford J, Scott T, Archuleta S, Levis SC, Spencer RL, Campeau S, Bachtell RK. Adolescent caffeine consumption increases adulthood anxiety-related behavior and modifies neuroendocrine signaling. Psychoneuroendocrinology. 2016;67:40-50

Patterson PD, Weaver MD, Frank RC, Warner CW, Martin-Gill C, Guyette FX, et al. Association between poor sleep, fatigue, and safety outcomes in emergency medical services providers. Prehosp Emerg Care. 2012;16(1):86-97.

Pylkkonen M, Sihvola M, Hyvarinen HK, Puttonen S, Hublin C, Sallinen M. Sleepiness, sleep, and use of sleepiness countermeasures in shift-working long-haul truck drivers. Accid Anal Prev. 2015;80:201-10.

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

Ronen A, Oron-Gilad T, Gershon P. The combination of short rest and energy drink consumption as fatigue countermeasures during a prolonged drive of professional truck drivers. J Safety Res. 2014;49:39-43. 34

Schweitzer PK, Randazzo AC, Stone K, Erman M, Walsh JK. Laboratory and field studies of naps and caffeine as practical countermeasures for sleep-wake problems associated with night work. Sleep. 2006;29(1):39-50.

Smith AP, Christopher G, Sutherland D. Acute effects of caffeine on attention: a comparison of non-consumers and withdrawn consumers. J Psychopharmacol. 2013;27(1):77-83.

Snel J, Lorist MM. Effects of caffeine on sleep and cognition. Prog Brain Res. 2011;190:105-17.

Tieges Z, Richard Ridderinkhof K, Snel J, Kok A. Caffeine strengthens action monitoring: evidence from the error-related negativity. Brain Res Cogn Brain Res. 2004;21(1):87-93.

Wesensten J. , G. Belenky, M.A. Kautz, D.R.Thorne, R.M. Reichardt, T.J. Balkin Maintaining alertness and performance during sleep deprivation: modafinil versus caffeine, Psychopharmacology, 159 (2002), pp. 238-247.

Wolk B.J. , M. Ganetsky, K.M. Babu, Toxicity of energy drinks, Curr. Opin. Pediatr., 24 (2012), pp. 243-251.

Yang A. , A.A. Palmer, H. deWitGenetics of caffeine consumption and responses to caffeine, Psychopharmacology, 211 (2010), pp. 245-257.



Font Size