Introduction
Coffee is well known for containing caffeine, which is a mild central nervous system stimulant (1,2). Drinking coffee can therefore have positive effects on an individual’s alertness and concentration so aiding better performance and this has been shown to be of benefit when an individual is feeling tired or lethargic. Strong evidence for the beneficial effects of regular caffeine consumption was shown using data from a cross-sectional survey of a sample of over 9000 British adults. Results showed regular coffee consumption improved cognitive performance (3).

Alleviating driver fatigue (4,5,6,&7)
Research has demonstrated, quite clearly, that a couple of cups of coffee and a short nap are the most effective way of alleviating driver fatigue. Many road traffic accidents occur as a result of a driver falling asleep at the wheel so any measure that can be taken to reduce the incidence of this, including drinking coffee, can only be for the good. The UK Department of Transport’s Think! Road Safety Campaign gives advice including, ‘Drink two cups of coffee or a high-caffeinated drink, then take a short nap to allow the caffeine to kick in’ http://think.direct.gov.uk/fatigue.html. London Resources also provides further advice for motorists.

Post lunch dip (8)
After lunch it is quite usual to experience what is known as `the post lunch dip’, this is when our bodies natural rhythms slow down and as a result we become less alert and find it difficult to concentrate. The caffeine contained in a couple of cups of coffee is sufficient to raise levels of alertness, and increase our concentration, enabling those at work to keep going until the end of the working day.

Night shift work (9)
With an increase in the ’24 hour society’ it is inevitable that more and more people will be required to work through the night and research has shown that these individuals may benefit from a couple of cups of coffee during the evening to help them concentrate better during the early hours of the morning. Importantly, neither the time taken to fall asleep, nor the quality of sleep, were affected by coffee consumed during the night shift.

Common cold (10)
Research from Bristol University has demonstrated that drinking coffee has been shown to add a `feel good’ factor and lift some of the sluggish symptoms that are the common after effects of a cold. Volunteers were tested when healthy and then again when they had a cold. The results were assessed and coffee increased alertness and performance of the sick volunteers to the same level as the healthy group.

Physical Performance (1,11-16)
Caffeine is widely reported to be an ergogenic aid i.e. a substance that improves the capacity to do work or exercise. It has been shown that caffeine consumption can improve athletic performance in numerous endurance events including swimming, cycling and women’s tennis.

Summary
Coffee is one of the most heavily researched commodities in the world today and the wealth of scientific evidence suggests that moderate coffee consumption, of 4-5 cups per day, is perfectly safe for the general population and may confer health benefits. Pregnant women should however moderate their intake following the guidelines issued by the Food Standards Agency, to 200mg caffeine per day from all sources.

The caffeine contained in a couple of cups of coffee (approx 120mg) increases alertness and performance, aids concentration and alleviates some of the sluggish symptoms associated with the common cold.

References
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2. Dorea et al, British Journal of Nutrition; 93:773-782, 2005 3. Jarvis MJ. Psychopharmacology, Volume 110, 1993
4. Horne & Reyner. Psychophysiology, Volume 34, 1997
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6. Phillip P. Annals of Internal Medicine, Volume 144, 2006
7. London Resources, http://www.officespaceinlondon.net/london/london-resources.htm                                                                                                                                         8. Smith AP. Neuropsychobiology, Volume 23, 1991
9. Smith AP. Neuropsychobiology, Volume 27, 1993
10. Smith AP. Journal of Psychopharmacology, Volume 11, 1997
11. Doherty M. Scandinavian Journal of Medicine and Sciences in Sports, Volume 15, 2005
12. Graham TE. Sports Medicine, Volume 31, 2001
13. MacIntosh BR and Wright BM. Canadian Journal of Applied Physiology, Volume 20, 1995
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15. Ferrauti A. Journal of Sports Medicine and Physical Fitness, Volume 37, 1997
16. Paluska, Current Sports Medicine Reports, 2, 213-219, 2003