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A combination of green tea extract and l-theanine improves memory and attention in subjects with mild cognitive impairment: a double-blind placebo-controlled study


Park, Sang-Ki, Jung, In-Chul, Lee, Won Kyung, Lee, Young Sun, Park, Hyoung Kook, Go, Hyo Jin, Kim, Kiseong, Lim, Nam Kyoo, Hong, Jin Tae, Ly, Sun Yung, Rho, Seok Seon


Journal Of Medicinal Food, Volume: 14, No.: 4, Pages.: 334-343

Year of Publication



A combination of green tea extract and l-theanine (LGNC-07) has been reported to have beneficial effects on cognition in animal studies. In this randomized, double-blind, placebo-controlled study, the effect of LGNC-07 on memory and attention in subjects with mild cognitive impairment (MCI) was investigated. Ninety-one MCI subjects whose Mini Mental State Examination-K (MMSE-K) scores were between 21 and 26 and who were in either stage 2 or 3 on the Global Deterioration Scale were enrolled in this study. The treatment group (13 men, 32 women; 57.58 ± 9.45 years) took 1,680 mg of LGNC-07, and the placebo group (12 men, 34 women; 56.28 ± 9.92 years) received an equivalent amount of maltodextrin and lactose for 16 weeks. Neuropsychological tests (Rey-Kim memory test and Stroop color-word test) and electroencephalography were conducted to evaluate the effect of LGNC-07 on memory and attention. Further analyses were stratified by baseline severity to evaluate treatment response on the degree of impairment (MMSE-K 21-23 and 24-26). LGNC-07 led to improvements in memory by marginally increasing delayed recognition in the Rey-Kim memory test (P = .0572). Stratified analyses showed that LGNC-07 improved memory and selective attention by significantly increasing the Rey-Kim memory quotient and word reading in the subjects with MMSE-K scores of 21-23 (LGNC-07, n = 11; placebo, n = 9). Electroencephalograms were recorded in 24 randomly selected subjects hourly for 3 hours in eye-open, eye-closed, and reading states after a single dose of LGNC-07 (LGNC-07, n = 12; placebo, n = 12). Brain theta waves, an indicator of cognitive alertness, were increased significantly in the temporal, frontal, parietal, and occipital areas after 3 hours in the eye-open and reading states. Therefore, this study suggests that LGNC-07 has potential as an intervention for cognitive improvement.;

Bibtex Citation

@article{Park_2011, doi = {10.1089/jmf.2009.1374}, url = {}, year = 2011, month = {apr}, publisher = {Mary Ann Liebert Inc}, volume = {14}, number = {4}, pages = {334--343}, author = {Sang-Ki Park and In-Chul Jung and Won Kyung Lee and Young Sun Lee and Hyoung Kook Park and Hyo Jin Go and Kiseong Kim and Nam Kyoo Lim and Jin Tae Hong and Sun Yung Ly and Seok Seon Rho}, title = { A Combination of Green Tea Extract and l -Theanine Improves Memory and Attention in Subjects with Mild Cognitive Impairment: A Double-Blind Placebo-Controlled Study }, journal = {Journal of Medicinal Food} }


aged, and, attention, chemistry, cognition disorders, double-blind method, drug combinations, drug effects, drug therapy, extract, female, glutamates, green, humans, ltheanine, male, memory, middle aged, neuropsychological tests, phytotherapy, plant extracts, tea, therapeutic use

Types of Dementia

Mild Cognitive Impairment (MCI)

Types of Study

Randomised Controlled Trial

Type of Outcomes


Type of Interventions

Pharmaceutical Interventions

Pharmaceutical Interventions

Herbal remedies, vitamins, dietary supplements