n/a
Article Publish Status: FREE
Abstract Title:

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

Abstract Source:

Nutrients. 2019 Oct 3 ;11(10). Epub 2019 Oct 3. PMID: 31623400

Abstract Author(s):

Shinsuke Hidese, Shintaro Ogawa, Miho Ota, Ikki Ishida, Zenta Yasukawa, Makoto Ozeki, Hiroshi Kunugi

Article Affiliation:

Shinsuke Hidese

Abstract:

This randomized, placebo-controlled, crossover, and double-blind trial aimed to examine the possible effects of four weeks L-theanine administration on stress-related symptoms and cognitive functions in healthy adults. Participants were 30 individuals (nine men and 21 women; age: 48.3± 11.9 years) who had no major psychiatric illness. L-theanine (200 mg/day) or placebo tablets were randomly and blindly assigned for four-week administration. For stress-related symptoms, Self-rating Depression Scale, State-Trait Anxiety Inventory-trait, and Pittsburgh Sleep Quality Index (PSQI) scores decreased after L-theanine administration (= 0.019, 0.006, and 0.013, respectively). The PSQI subscale scores for sleep latency, sleep disturbance, and use of sleep medication reduced after L-theanine administration, compared to the placebo administration (all<0.05). For cognitive functions, verbal fluency and executive function scores improved after L-theanine administration (= 0.001 and 0.031, respectively). Stratified analyses revealed that scores for verbal fluency (= 0.002), especially letter fluency (= 0.002), increased after L-theanine administration, compared to the placebo administration, in individuals who were sub-grouped into the lower half by the median split based on the mean pretreatment scores. Our findings suggest that L-theanine has the potential to promote mental health in the general population with stress-related ailments and cognitive impairments.

Study Type : Human Study
Additional Links

Print Options


Key Research Topics

This website is for information purposes only. By providing the information contained herein we are not diagnosing, treating, curing, mitigating, or preventing any type of disease or medical condition. Before beginning any type of natural, integrative or conventional treatment regimen, it is advisable to seek the advice of a licensed healthcare professional.

© Copyright 2008-2024 GreenMedInfo.com, Journal Articles copyright of original owners, MeSH copyright NLM.