The association between caffeine consumption and an increase in alertness and performance has been well documented1. The European Food Safety Authority (EFSA) concluded that a cause and effect relationship has been established between a 75mg serving of caffeine – the amount found in approximately 1 regular cup of coffee – and both increased attention (concentration) and alertness, mainly in situations of low arousal1.
A 2020 meta-analysis concludes that caffeine improved response time and accuracy on attention tests; this included improved executive function, reaction time, and response time, as well as accuracy on information processing tasks, and enhanced lateral and longitudinal measures of vehicular control during simulated driving tests. Studies also typically indicated caffeine’s benefits on memory, physical and occupational performance. Caffeine consumption is an effective counter-measure to the cognitive and physical impairments associated with sleep loss2.
This effect of caffeine on increasing alertness may cause sleep problems in some, dependent on the amount of caffeine consumed per day and the genetic makeup of individuals, although caffeine abstinence may help to improve sleep3,4.
Caffeine has also been associated with a pattern of sustained improvement of mood over the day, particularly among fatigued individuals5, although high intakes may be associated with an increase in feelings of anxiety, nervousness and jitteriness5.
The content in this Topic Overview was last edited in December 2023. Papers in the Latest Research section and further resources are added regularly.
