Coffee & Health
Mental performance

New report explores effect of coffee through our daily sleep and wake cycles

March 3, 2021

The Institute for Scientific Information on Coffee (ISIC) published a new report today, titled ‘Coffee and sleep in everyday lives’, authored by Professor Renata Riha, from the Department of Sleep Medicine at the University of Edinburgh.

The report reviews the latest research into coffee’s effect on sleep and suggests that while drinking coffee early in the day can help support alertness and concentration levels1, especially when sleep patterns are disturbed; decreasing intake six hours before bedtime may help reduce its impact on sleep2.

Coffee is largely consumed daily for the pleasure of its taste3, as well as its beneficial effect on wakefulness and concentration (due to its caffeine content)4. This may be particularly the case for those experiencing restricted sleep, and those adjusting to new sleep/wake cycles, such as shiftworkers5.

For those affected by restricted sleep, regular coffee can help to effectively mitigate short-term cognitive impairment brought about by sleep loss4. This was reported in a study which found that consuming 300mg of caffeine (or three cups of coffee) per day can help to improve people’s vigilance, alertness, reaction-time, accuracy and working memory in the first three days of poor sleep, compared to decaffeinated coffee4. For those working nightshifts, consuming caffeine has been found to improve psychomotor performance and vigilance, based on a study of emergency medical teams6. However, the researchers of this study note that it may affect later sleep quality and duration6.

Furthermore, the report highlights another interesting relationship between the impact of coffee consumption timing on sleep time and quality, especially when consumed close to sleep time7. The report findings suggest that caffeine’s effect on sleep depends on the amount consumed throughout the day, individual susceptibilities and consumption habits7,8,9. For those sensitive to caffeine, limiting consumption six hours prior to sleep time can help lessen its effects2.

The author, Professor Renata Riha commented: “Caffeine is consumed daily by roughly 80% of the world’s population, often for its benefits in promoting wakefulness and concentration. Its effects can last for several hours, depending on how quickly or slowly it is metabolised by the body. Those who find that drinking coffee later in the day disrupts their sleep patterns may wish to swap to low caffeine drinks, or decaffeinated coffee during the afternoon and evening.”

To read the report entitled, ‘Coffee and sleep in everyday lives’, click here.


Additional background information on coffee can be found at, a science-based resource developed for healthcare and other professional audiences, providing the latest information and research into coffee, caffeine and health.

Notes to editors

  • Moderate coffee consumption can be defined as 3–5 cups per day, based on the European Food Safety Authority’s review of caffeine safety10.
  • Pregnant and breastfeeding women are advised to limit their caffeine intake to 200 mg per day10.

Author of the report

  • Renata Riha, Centre for Clinical Brain Sciences, Sleep Research Unit, Department of Sleep Medicine, Royal Infirmary of Edinburgh, The University of Edinburgh.


  1. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) (2011) Scientific Opinion on the substantiation of health claims related to caffeine and increased fat oxidation leading to a reduction in body fat mass (ID 735, 1484), increased energy expenditure leading to a reduction in body weight (ID 1487), increased alertness (ID 736, 1101, 1187, 1485, 1491, 2063, 2103) and increased attention (ID 736, 1485, 1491, 2375) pursuant to Article 13(1) of Regulation (EC) No 1924/20061. EFSA Journal, 9(4):2054.
  2. Drake C. et al. (2013) Caffeine Effects on Sleep Taken 0, 3, or 6 Hours before Going to Bed. J Clin Sleep Med, 9(11): 1195-1200.
  3. Nieber K. (2017) The Impact of Coffee on Health. Planta Med, 83: 1256–1263.
  4. Baur DM et al. (2021) Coffee effectively attenuates impaired attention in ADORA2A C/C-allele carriers during chronic sleep restriction. Progress in Neuro-Psychopharmacology and Biological Psychiatry. Published online ahead of print.
  5. Kolla B.P., Auger R.R. (2011) Jet lag and shift work sleep disorders: how to help reset the internal clock.Cleve Clin J Med, 78(10):675-84.
  6. Temple J.L. (2018) Systematic Review and Meta-analysis of the Effects of Caffeine in Fatigued Shift Workers: Implications for Emergency Medical Services Personnel. Prehosp Emerg Care, 22(Supp1):37-46.
  7. Clark I. and Landolt H.P. (2016) Coffee, Caffeine, and Sleep. Sleep Med Rev, 31:70-78.
  8. Roehrs T. et al. (2008) Caffeine: sleep and daytime sleepiness. Sleep Med Rev, 12:153-62.
  9. Elmenhorst D. et al. (2007) Sleep deprivation increases A1 Adenosine receptor binding in the human brain: A positron emission tomography study. J Neurosci, 27(9):2410-2415.
  10. EFSA (2015) Scientific Opinion on the Safety of Caffeine, EFSA Journal, 13(5):4102.

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