#Note/Permanent #Nutrition/Caffeine/Tools #Health/L-Theanine ## Overview Recent studies have underscored the synergistic effects of combining [L-theanine](https://en.wikipedia.org/wiki/Theanine) with caffeine. This combination is particularly effective in enhancing cognitive functions and mitigating some of the negative side effects often associated with caffeine intake, such as jitteriness, anxiety, and blood pressure rise[^3]. ## Enhancement of Cognitive Performance[^1] - **Improved Reaction Times and Accuracy**: The L-theanine and caffeine combination has been shown to improve various cognitive metrics, including simple reaction time, accuracy in Rapid Visual Information Processing (RVIP), numeric working memory reaction time, and delayed word recognition reaction time. - **Enhanced Attention and Memory**: Contrary to caffeine alone, which primarily boosts attention and alertness, the addition of L-theanine exhibits a greater effect on memory tasks, typically less influenced by caffeine. - **Increased Alertness**: Alertness ratings were higher with the L-theanine and caffeine combination compared to caffeine alone. ## Mitigation of Negative Effects - **Reduced Jitteriness and Anxiety**[^1] : High doses of caffeine, even within a [[Caffeine Dosage Guidelines|safe range]], can induce side effects like jitteriness and anxiety[^2]. Research shows that combining L-theanine with caffeine can mitigate these effects and improve overall mood. - **Attenuated Blood Pressure Rise**[^4] : Caffeine can cause a rise in blood pressure, posing risks to individuals with [hypertension](https://en.wikipedia.org/wiki/Hypertension) (high blood pressure). Studies indicate that L-theanine and caffeine together can counteract the caffeine-induced rise in blood pressure. ## Conclusion The combination of L-theanine and caffeine provides enhanced cognitive benefits while reducing some of caffeine's less desirable effects, such as jitteriness, blood pressure rise and over-stimulation. This synergy is particularly beneficial for tasks requiring both memory and sustained attention, offering a balanced approach to cognitive enhancement. [^1]: [The effects of L-theanine, caffeine and their combination on cognition and mood](https://pubmed.ncbi.nlm.nih.gov/18006208/) [^2]: [Effects of caffeine on sleep quality and daytime functioning](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6292246/) [^3]: [The effect of coffee on blood pressure and cardiovascular disease in hypertensive individuals: a systematic review and meta-analysis](https://www.sciencedirect.com/science/article/pii/S0002916523024814?via%3Dihub) [^4]: [Time for tea: mood, blood pressure and cognitive performance effects of caffeine and theanine administered alone and together](https://link.springer.com/article/10.1007/s00213-007-0938-1)