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.
abstract: 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.
authors.affiliation: LG Household and Health Care Co., Ltd., Daejeon, Korea.
authors.forename: Sang-Ki
authors.initials: SK
authors.lastname: Park
authors.forename: In-Chul
authors.initials: IC
authors.lastname: Jung
authors.forename: Won Kyung
authors.initials: WK
authors.lastname: Lee
authors.forename: Young Sun
authors.initials: YS
authors.lastname: Lee
authors.forename: Hyoung Kook
authors.initials: HK
authors.lastname: Park
authors.forename: Hyo Jin
authors.initials: HJ
authors.lastname: Go
authors.forename: Kiseong
authors.initials: K
authors.lastname: Kim
authors.forename: Nam Kyoo
authors.initials: NK
authors.lastname: Lim
authors.forename: Jin Tae
authors.initials: JT
authors.lastname: Hong
authors.forename: Sun Yung
authors.initials: SY
authors.lastname: Ly
authors.forename: Seok Seon
authors.initials: SS
authors.lastname: Rho
mesh_terms: D000368:Aged; D001288:Attention / Q000187:drug effects; D003072:Cognition Disorders / Q000188:drug therapy*; D004311:Double-Blind Method; D004338:Drug Combinations; D005260:Female; D005971:Glutamates / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008568:Memory / Q000187:drug effects*; D008875:Middle Aged; D009483:Neuropsychological Tests; D008517:Phytotherapy; D010936:Plant Extracts / Q000627:therapeutic use*; D013662:Tea / Q000737:chemistry*
chemical_list: D004338:Drug Combinations; D005971:Glutamates; D010936:Plant Extracts; D013662:Tea; C026166:theanine