Green Tea Extract and L-theanine Improves Memory and Attention in Mild Cognitive Impairment
Ninety-one subjects with mild cognitive impairment were randomized to 1440 mg of green tea extract and 240 mg of L-theanine per day or placebo for 16 weeks. The subjects scored between 21-26 on the Mini Mental State Examination-K (MMSE-K) and were either stage 2 or 3 on the Global Deterioration Scale. Those subjects with an initial MMSE-K score of 21-23 showed a significant memory quotient increase and an improvement in immediate recall compared to baseline. This group also showed improvement in the Stroop colour-word reading test compared to placebo at 8 weeks, while the placebo group did not demonstrate any improvements. However, the total improvements were not statistically different between the treatment and control groups.
Brain theta waves were significantly increased in the temporal, frontal, parietal, and occipital areas after 3 hours in the eye-open and reading states after a single dose of360 mg green tea extract and 60 mg of lL-theanine.
J Med Food. 2011 Apr;14(4):334-43. Epub 2011 Feb 8.