Acute effects of tea constituents L-theanine, caffeine, and epigallocatechin gallate on cognitive function and mood: a systematic review and meta-analysis.

@article{Camfield2014AcuteEO,
  title={Acute effects of tea constituents L-theanine, caffeine, and epigallocatechin gallate on cognitive function and mood: a systematic review and meta-analysis.},
  author={David Camfield and Con Stough and Jon Farrimond and Andrew Scholey},
  journal={Nutrition reviews},
  year={2014},
  volume={72 8},
  pages={
          507-22
        }
}
A systematic review and meta-analysis was conducted on 11 randomized placebo-controlled human studies of acute effects of tea constituents L-theanine and epigallocatechin gallate, administered alone or in combination with caffeine, on cognitive function and mood. [] Key Method The outcome measures of mood were alertness, calmness, and contentedness, derived from the Bond-Lader scales, and state anxiety, from the State-Trait Anxiety Inventory.

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References

SHOWING 1-10 OF 39 REFERENCES
Time for tea: mood, blood pressure and cognitive performance effects of caffeine and theanine administered alone and together
TLDR
Evidence suggests that theanine is a physiologically and behaviourally active compound and, while it is unclear how its effects might explain perceived differences between tea and coffee, evidence suggests that it may be useful for reducing raised blood pressure.
L-theanine and caffeine in combination affect human cognition as evidenced by oscillatory alpha-band activity and attention task performance.
TLDR
Electrophysiological results did not show increased differential biasing in phasic alpha across hemifields but showed lower overall tonic alpha power in the combined treatment, similar to previous findings at a larger dosage of L-theanine alone.
The acute effects of L‐theanine in comparison with alprazolam on anticipatory anxiety in humans
TLDR
It is suggested that while L‐ theanine may have some relaxing effects under resting conditions, neither L‐theanine not alprazolam demonstrate any acute anxiolytic effects under conditions of increased anxiety in the AA model.
The combined effects of L-theanine and caffeine on cognitive performance and mood
TLDR
Caffeine and L-theanine in combination improved both speed and accuracy of performance of the attention-switching task and reduced susceptibility to distracting information in the memory task at both 60 min and 90 min.
Gender differences in tea, coffee, and cognitive decline in the elderly: the Cardiovascular Health Study.
Although caffeine can enhance cognitive function acutely, long-term effects of consumption of caffeine-containing beverages such as tea and coffee are uncertain. Data on 4,809 participants aged 65
Caffeine as an attention enhancer: reviewing existing assumptions
TLDR
Evidence shows that caffeine has clear beneficial effects on attention, and that the effects are even more widespread than previously assumed.
...
...