Story perspectives

Study: Caffeine and L-Theanine Boost Alertness in Sleep-Deprived

10/23/2025

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Summary

Story summary

A study published in the British Journal of Nutrition found that 200 mg of L-theanine and 160 mg of caffeine can enhance attention and reaction time in sleep-deprived individuals.
In the 37-young-adult sample, participants who took the combination identified potential traffic accidents more accurately than those given a placebo after 17 hours awake.
Brainwave data supported the improvement, and researchers call for further studies on long-term effects and real-world use.

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Story summary

A study published in the British Journal of Nutrition found that 200 mg of L-theanine and 160 mg of caffeine can enhance attention and reaction time in sleep-deprived individuals.
In the 37-young-adult sample, participants who took the combination identified potential traffic accidents more accurately than those given a placebo after 17 hours awake.
Brainwave data supported the improvement, and researchers call for further studies on long-term effects and real-world use.