theanine and Sleep-Wake-Disorders

The green tea amino acid theanine is abundant in green tea rather than black and oolong teas, which are all made of the identical tea plant "Chanoki" (Camellia sinensis). Theanine has a molecular structure close to glutamine (GLN) compared to glutamic acid (Glu), in terms of the absence of a free carboxylic acid moiety from the gamma carbon position. Theanine efficiently inhibits [

Topics: Amino Acid Transport System A; Animals; Brain; Cognition Disorders; Double-Blind Method; Forecasting; Glutamates; Glutamine; Hippocampus; Humans; Mechanistic Target of Rapamycin Complex 1; Mice; Mice, Transgenic; Mood Disorders; Neural Stem Cells; Neurogenesis; Neuroprotective Agents; Phosphorylation; Phytotherapy; Protein Processing, Post-Translational; Randomized Controlled Trials as Topic; Rats; Sleep Wake Disorders; Tea; TOR Serine-Threonine Kinases

Sleep deprivation is associated with an elevated risk of various diseases and leads to a poor quality of life and negative socioeconomic consequences. Sleep inducers such as drugs and herbal medicines may often lead to dependence and other side effects. L-Theanine (γ-glutamylethylamide), an amino acid naturally found abundant in tea leaves, has anxiolytic effects via the induction of α brain waves without additive and other side effects associated with conventional sleep inducers. Anxiolysis is required for the initiation of high-quality sleep. In this study, we review the mechanism(s), safety, and efficacy of L-theanine. Collectively, sleep studies based on an actigraph, the obstructive sleep apnea (OSA) sleep inventory questionnaire, wakeup after sleep onset (WASO) and automatic nervous system (ANS) assessment, sympathetic and parasympathetic nerve activities, and a pediatric sleep questionnaire (PSQ) suggest that the administration of 200 mg of L-theanine before bed may support improved sleep quality not by sedation but through anxiolysis. Because L-theanine does not induce daytime drowsiness, it may be useful at any time of the day. The no observable adverse effect level (NOAEL) for the oral administration of L-theanine was determined to be above 2000 mg/kg bw/day. KEY TEACHING POINTS: Sleep deprivation-associated morbidity is an increasing public health concern posing a substantial socioeconomic burden. Chronic sleep disorders may seriously affect quality of life and may be etiological factors in a number of chronic diseases such as depression, obesity, diabetes, and cardiovascular diseases. Most sleep inducers are sedatives and are often associated with addiction and other side effects. L-Theanine promotes relaxation without drowsiness. Unlike conventional sleep inducers, L-theanine is not a sedative but promotes good quality of sleep through anxiolysis. This review suggests that L-theanine is a safe natural sleep aid.

Topics: Glutamates; Humans; No-Observed-Adverse-Effect Level; Plant Extracts; Plant Leaves; Quality of Life; Randomized Controlled Trials as Topic; Sleep Wake Disorders; Socioeconomic Factors; Tea

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 (

Topics: Adult; Anxiety; Body Mass Index; Cognition; Cross-Over Studies; Depression; Double-Blind Method; Female; Glutamates; Humans; Male; Middle Aged; Placebos; Sleep Wake Disorders; Stress, Psychological

The purpose of this study was to investigate the efficacy and safety of L-theanine as an aid to the improvement of objectively measured sleep quality in a population of 98 male children formally diagnosed with attention-deficit/hyperactivity disorder (ADHD).. A randomized, double-blind, placebo-controlled trial was conducted involving boys, ages 8-12 years, who had been previously diagnosed with ADHD. An experienced physician confirmed the diagnosis of ADHD in each subject. Randomization was stratified based upon current use of stimulant medication to ensure an equal distribution of stimulant/non-stimulant treated subjects into active and placebo treated groups. Participants consumed two chewable tablets twice daily (at breakfast and after school), with each tablet containing 100 mg of L-theanine (total 400 mg daily Suntheanine®, Taiyo Kagaku, Yokkaichi, Japan) or identical tasting chewable placebo for six weeks. Subjects were evaluated for five consecutive nights using wrist actigraphy at baseline, and again at the end of the six-week treatment period. The Pediatric Sleep Questionnaire (PSQ) was completed by parents at baseline and at the end of the treatment period.. Actigraph watch data findings indicated that boys who consumed L-theanine obtained significantly higher sleep percentage and sleep efficiency scores, along with a non-significant trend for less activity during sleep (defined as less time awake after sleep onset) compared to those in the placebo group. Sleep latency and other sleep parameters were unchanged. The PSQ data did not correlate significantly to the objective data gathered from actigraphy, suggesting that parents were not particularly aware of their children's sleep quality. L-theanine at relatively high doses was well tolerated with no significant adverse events.. This study demonstrates that 400 mg daily of L-theanine is safe and effective in improving some aspects of sleep quality in boys diagnosed with ADHD. Since sleep problems are a common co-morbidity associated with ADHD, and because disturbed sleep may be linked etiologically to this disorder, L-theanine may represent a safe and important adjunctive therapy in childhood ADHD. Larger, long-term studies looking at the wider therapeutic role of this agent in this population are warranted.

Topics: Actigraphy; Administration, Oral; Attention Deficit Disorder with Hyperactivity; Child; Complementary Therapies; Double-Blind Method; Glutamates; Humans; Male; Sleep Wake Disorders; Surveys and Questionnaires; Treatment Outcome

L-theanine has been reported to inhibit the excitatory effects of caffeine. The present study examined the effects of L-theanine on caffeine-induced sleep disturbances in rats. Rats received the following drug pairings: saline and saline (Control), 7.5 mg/kg caffeine and saline, or 7.5 mg/kg of caffeine followed by various doses of L-theanine (22.5, 37.5, 75, or 150 mg/kg). Vigilance states were divided into: wakefulness (W), transition to slow-wave sleep (tSWS), slow-wave sleep (SWS), and rapid-eye-movement sleep (REMS). Caffeine significantly increased the duration of W and decreased the duration of SWS and REMS compared to the Control. Although L-theanine failed to reverse the caffeine-induced W increase, at 22.5 and 37.5 mg/kg (but not at 75 and 150 mg/kg), it significantly reversed caffeine-induced decreases in SWS. In conclusion, low doses of L-theanine can partially reverse caffeine-induced reductions in SWS; however, effects of L-theanine on caffeine-induced insomnia do not appear to increase dose-dependently.

Topics: Animals; Caffeine; Dose-Response Relationship, Drug; Glutamates; Male; Rats; Rats, Sprague-Dawley; Sleep Stages; Sleep Wake Disorders; Wakefulness