Does caffeine intake enhance absolute levels of cognitive performance?

Psychopharmacology (Berl). 1993;110(1-2):45-52. doi: 10.1007/BF02246949.


The relationship between habitual coffee and tea consumption and cognitive performance was examined using data from a cross-sectional survey of a representative sample of 9003 British adults (the Health and Lifestyle Survey). Subjects completed tests of simple reaction time, choice reaction time, incidental verbal memory, and visuo-spatial reasoning, in addition to providing self-reports of usual coffee and tea intake. After controlling extensively for potential confounding variables, a dose-response trend to improved performance with higher levels of coffee consumption was observed for all four tests (P < 0.001 in each case). Similar but weaker associations were found for tea consumption, which were significant for simple reaction time (P = 0.02) and visuo-spatial reasoning (P = 0.013). Estimated overall caffeine consumption showed a dose-response relationship to improved cognitive performance (P < 0.001 for each cognitive test, after controlling for confounders). Older people appeared to be more susceptible to the performance-improving effects of caffeine than were younger. The results suggest that tolerance to the performance-enhancing effects of caffeine, if it occurs at all, is incomplete.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Age Factors
  • Aged
  • Caffeine / pharmacology*
  • Choice Behavior / drug effects
  • Coffee
  • Cognition / drug effects*
  • Dose-Response Relationship, Drug
  • Female
  • Humans
  • Male
  • Memory / drug effects
  • Middle Aged
  • Psychomotor Performance / drug effects*
  • Reaction Time / drug effects
  • Space Perception / drug effects
  • Tea
  • Thinking / drug effects
  • United Kingdom


  • Coffee
  • Tea
  • Caffeine