CRCT · 50 analyzed adults aged 50 to 69, 12 weeks

Effects of L-Theanine on Cognitive Function in Middle-Aged and Older Subjects: A Randomized Placebo-Controlled Study

Y Baba, S Inagaki, S Nakagawa, T Kaneko, M Kobayashi, T Takihara. Journal of Medicinal Food. 2021.

Published 2026-10-15Sources checked 2026-10-151 sourceEverstack research teamHow we work

In plain language: A single dose of about 100 mg improved some attention and working memory scores; 12 weeks of daily intake showed no effect on attention.
Limits: Sponsored by ITO EN, which supplied the capsules; many tests; small sample.
Source: doi.org/10.1089/jmf.2020.4803 · PubMed 33751906 · Free full text

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