rct
    2019
    High Quality

    Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial

    Hidese S, Ogawa S, Ota M, Ishida I, Yasukawa Z, Ozeki M, Kunugi H

    Published in Nutrients

    Methodology

    Randomized, placebo-controlled, crossover trial of L-theanine 200 mg/day for four weeks in healthy adults without major psychiatric illness, assessing stress, sleep and cognition.

    Key Findings

    L-theanine reduced stress-related symptoms including sleep-latency, sleep disturbance and use of sleep medication scores, and improved verbal fluency and executive function in a subgroup analysis.

    Conclusions

    Four weeks of L-theanine may reduce stress-related symptoms and support cognitive function in healthy adults.

    Limitations

    Small crossover sample; several outcomes exploratory; partly funded by an ingredient manufacturer.

    Supplements Studied

    L-Theanine
    Amino Acid

    L-theanine reduced stress-related symptoms including sleep latency and sleep disturbance, and improved verbal fluency and executive function.

    Outcomes Measured

    L-theanine reduced sleep latency, sleep disturbance and stress-related symptom scores.

    L-theanine reduced sleep latency, sleep disturbance and stress-related symptom scores.

    Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial

    L-theanine reduced stress-related symptoms including sleep-latency, sleep disturbance and use of sleep medication scores, and improved verbal fluency and executive function in a subgroup analysis.

    L-theanine reduced stress-related symptoms including sleep-latency, sleep disturbance and use of sleep medication scores, and improved verbal fluency and executive function in a subgroup analysis.

    Related Health Concerns

    Study Details

    Year:2019
    Sample Size:30
    Duration:4 weeks
    Quality Score:7/10

    Disclosures

    Funding

    Japanese academic funding with support from an ingredient manufacturer

    This information is for educational purposes only. Always consult a healthcare professional before starting any supplement regimen.