Improves Cognitive Function

L-theanine is a nootropic or cognitive enhancer. Studies show that consumption of this compound can help improve various cognitive parameters:
1. In young adults, supplementation with 97 mg of L-theanine improved focus attention during a demanding cognitive task. [1]
2. In healthy male volunteers, L-theanine supplementation at dose of 200 mg improved cognitive and neurophysiological measures of selective attention. [2]
3. In men and women with mild cognitive impairment, a combination of L-theanine and green tea extract improved memory in a test assessing recognition and increased the levels of brain theta waves, an indicator of cognitive alertness. [3]
4. In healthy volunteers, L-theanine administration improved speed and accuracy of performance of the attention-switching task and reduced the rate of errors in the memory task. [4]
5. In healthy, young participants, L-theanine administration at a dose of 500 mg improved mental alertness and increased alpha activity in the electroencephalogram, which is indicative of improved attention. [5]
6. L-theanine administration at a dose of 250 mg led to faster reaction time and numeric working memory reaction time and improved sentence verification accuracy in healthy human subjects. [6]
7. In healthy volunteers, L-theanine supplementation improved working memory and performance task. [7]
8. In elderly persons with normal or slight cognitive dysfunction, ingestion of powdered green tea containing a high L-theanine concentration significantly reduced cognitive decline. [8]
9. A study found that L-theanine may provide effective prophylaxis and treatment for Alzheimer’s disease by preventing programmed cell death (apoptosis) of brain cells. [9]
10. In rats, ingestion of water containing 0.3% L-theanine for 3 weeks was associated with improved recognition memory. [10]
11. In animal models, L-theanine improved learning and memory possibly through its neuroprotective effects. [11]
12. In a mouse model of Alzheimer’s disease, L-theanine ameliorated memory impairment. [12]
13. In rats, ingestion of L-theanine for 3 weeks ad libitum improved learning and memory. [13]