L-테아닌 (진정)

Performance-enhancing effects of caffeine and L-Theanine among Iranian elite wrestlers: a focus on cognitive and specific physical performance.

1. J Int Soc Sports Nutr. 2025 Dec;22(1):2564238. doi: 10.1080/15502783.2025.2564238. Epub 2025 Sep 22. Performance-enhancing effects of caffeine and L-Theanine among Iranian elite wrestlers: a focus on cognitive and specific physical performance. Razazan R(1), Hemmatinafar M(1), Imanian B(1), J

The effect of green tea amino acid L-theanine formulation on markers of stress and quality of sleep (THESleep project) - a study protocol for a pilot randomised control trial.

1. Contemp Clin Trials. 2026 Apr 15;165:108306. doi: 10.1016/j.cct.2026.108306. Online ahead of print. The effect of green tea amino acid L-theanine formulation on markers of stress and quality of sleep (THESleep project) - a study protocol for a pilot randomised control trial. Bulman A(1), McKune A(2), Georgousopoulou E(3), Sergi D(4), Naumovski N(5). Author information: (1)Faculty of Health, University of Canberra, Bruce, Canberra, ACT 2617, Australia; Functional Foods and Nutrition Research (FFNR) Laboratory, Singapore Institute of Technology, Punggol 828628, Singapore; University of Canberra Research Institute of Sport and Exercise (UCRISE), University of Canberra, Canberra, ACT 2617, Australia. Electronic address: Amanda.Bulman@canberra.edu.au. (2)Faculty of Health, University of Canberra, Bruce, Canberra, ACT 2617, Australia; Functional Foods and Nutrition Research (FFNR) Laboratory, Singapore Institute of Technology, Punggol 828628, Singapore; University of Canberra Research Institute of Sport and Exercise (UCRISE), University of Canberra, Canberra, ACT 2617, Australia; Discipline of Biokinetics, Exercise and Leisure Sciences, School of Health Sciences, University of KwaZulu-Natal, Durban 4000, South Africa. (3)Faculty of Health, University of Canberra, Bruce, Canberra, ACT 2617, Australia. (4)Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy. (5)Faculty of Health, University of Canberra, Bruce, Canberra, ACT 2617, Australia; Functional Foods and Nutrition Research (FFNR) Laboratory, Singapore Institute of Technology, Punggol 828628, Singapore; University of Canberra Research Institute of Sport and Exercise (UCRISE), University of Canberra, Canberra, ACT 2617, Australia; Food, Chemical and Biotechnology Cluster, Singapore Institute of Technology, Punggol 828628, Singapore; School of Medicine and Psychology, Australian National University, Science Rd, Canberra, ACT 2601, Australia. Electronic address: nenad.naumovski@singaporetech.edu.sg. L-theanine (L-THE) is a non-proteinogenic amino acid predominantly found in the leaves of the tea plant, Camelia sinensis, whose varieties produce green, white, oolong, black, aged Pu-erh, and ripened Pu-erh teas. The potential nootropic effects of L-THE, particularly for alleviating stress and anxiety and improving sleep quality, have seen an increase in its commercial application in products such as functional beverages and supplements despite the lack of conclusive evidence in the literature. The aim of this research project was to evaluate the effects of different concentrations of L-THE, in the form of a functional beverage sachet, on sleep and stress markers in individuals with mild to moderate sleep disturbances and determine an optimal concentration. In this randomised, double-blind, placebo-controlled, parallel-group, four-arm, dose response intervention trial, sixty healthy participants aged 18-65 with mild to moderate sleep disturbances were recruited to the study (UCHREC Approval Number: 2023-13247 and ACTRN12623000776606; Universal Trial Number (UTN) is U1111-1292-0328). Enrolled participants were randomly allocated to one of four treatment arms (100mg L-THE, 200mg L-THE, 400mg L-THE or placebo) in a 1:1:1:1 ratio, where they consumed a functional beverage for 14-days following a 7-day baseline period. The primary outcomes of this study were changes from baseline in objective and subjective sleep quality parameters alongside changes in secondary outcome measures of biochemical, physiological, and subjective stress markers relative to baseline. This clinical trial is the first to comprehensively evaluate the effectiveness (optimal dose) of L-THE at improving sleep quality and stress markers using a suite of objective, subjective, physiological, and biochemical tools. Copyright © 2026 The Authors. Published by Elsevier Inc. All rights reserved. DOI: 10.1016/j.cct.2026.108306 PMID: 41991056 Conflict of interest statement: Declaration of competing interest The authors declare no conflicts of interest.

Examining the effect of L-theanine on sleep: a systematic review of dietary supplementation trials.

2. Nutr Neurosci. 2026 Feb;29(2):224-238. doi: 10.1080/1028415X.2025.2556925. Epub 2025 Nov 1. Examining the effect of L-theanine on sleep: a systematic review of dietary supplementation trials. Cotter J(1), Caddick CE(2), Harper JL(2), Ebajemito JK(2). Author information: (1)Research and Development, The Water Street Collective, Southampton, UK. (2)Research and Development, British American Tobacco (Investments) Ltd, Southampton, UK. Objective: Sleep problems are a common complaint among adults worldwide, however, the use of prescription and over-the-counter products may not always be an appropriate or desirable solution. L-theanine is a naturally occurring, non-protein amino acid that can be found in the leaves of the tea plant Camellia sinensis. Previous studies have reported that consumption of L-theanine can help to aid relaxation, without causing sedation or adversely impacting cognitive function. Building on these calming effects and results from recent pre-clinical studies, the aim of this review was to systematically appraise the scientific literature to establish whether dietary supplementation with L-theanine can also help to support sleep in humans.Methods: Electronic database searches of Ovid MEDLINE, PsycINFO, Embase, CENTRAL and Google Scholar were conducted from inception to 3rd February 2025. Retrieved articles were independently reviewed by three authors.Results: Thirteen eligible trials (n = 550) that examined the effect of L-theanine (50-900 mg/day) as a standalone intervention on sleep-related outcome measures were identified. This included two single-arm, open-label trials and eleven randomised controlled trials.Discussion: Based on the current evidence, supplementation with 200-450 mg/day of L-theanine appears to be a safe and effective way to support healthy sleep in adults. Among the included trials, beneficial effects were reported on both objective and participant-reported outcomes, including measures linked to sleep latency, maintenance and efficiency, perceived sleep satisfaction and feelings of refreshment and recovery on waking. Further high-quality trials using objective measures, into the mechanisms underlying these effects, and among those with clinical insomnia would provide further useful insights. DOI: 10.1080/1028415X.2025.2556925 PMID: 41176609 [Indexed for MEDLINE]

The effects of L-theanine consumption on sleep outcomes: A systematic review and meta-analysis.

3. Sleep Med Rev. 2025 Jun;81:102076. doi: 10.1016/j.smrv.2025.102076. Epub 2025 Feb 25. The effects of L-theanine consumption on sleep outcomes: A systematic review and meta-analysis. Bulman A(1), D'Cunha NM(2), Marx W(3), Turner M(4), McKune A(5), Naumovski N(6). Author information: (1)Faculty of Health, University of Canberra, Bruce, Canberra, ACT, 2617, Australia; Functional Foods and Nutrition Research (FFNR) Laboratory, University of Canberra, Bruce, Canberra, ACT, 2617, Australia; University of Canberra Research Institute of Sport and Exercise (UCRISE), University of Canberra, Canberra, ACT, 2617, Australia. (2)Faculty of Health, University of Canberra, Bruce, Canberra, ACT, 2617, Australia; Functional Foods and Nutrition Research (FFNR) Laboratory, University of Canberra, Bruce, Canberra, ACT, 2617, Australia; Centre for Ageing Research and Translation, University of Canberra, Canberra, ACT, 2617, Australia. (3)Food & Mood Centre, IMPACT-The Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Deakin University, Barwon Health, Geelong, VIC, 3220, Australia. (4)Faculty of Health, University of Canberra, Bruce, Canberra, ACT, 2617, Australia. (5)Faculty of Health, University of Canberra, Bruce, Canberra, ACT, 2617, Australia; Functional Foods and Nutrition Research (FFNR) Laboratory, University of Canberra, Bruce, Canberra, ACT, 2617, Australia; University of Canberra Research Institute of Sport and Exercise (UCRISE), University of Canberra, Canberra, ACT, 2617, Australia; Discipline of Biokinetics, Exercise and Leisure Sciences, School of Health Sciences, University of KwaZulu-Natal, Durban, 4000, South Africa. (6)Faculty of Health, University of Canberra, Bruce, Canberra, ACT, 2617, Australia; Functional Foods and Nutrition Research (FFNR) Laboratory, University of Canberra, Bruce, Canberra, ACT, 2617, Australia; University of Canberra Research Institute of Sport and Exercise (UCRISE), University of Canberra, Canberra, ACT, 2617, Australia; Discipline of Nutrition-Dietetics, Harokopio University, Athens, 17671, Greece. Electronic address: Nenad.Naumovski@canberra.edu.au. This systematic review ansd meta-analysis aimed to evaluate the effects of L-theanine, a non-proteinogenic amino acid found in tea, on sleep outcomes. Literature searches were conducted in five electronic databases (APA PsycINFO, CINAHL, Medline, Scopus, Web of Science), and one register (Cochrane Central Register of Controlled Trials) from inception until September 2024. Randomised controlled trials investigating the effects of L-theanine supplementation on sleep quality in humans of all ages and health status were included. Nineteen articles (N = 897 participants) were selected and 18 included in the meta-analysis. L-theanine was shown to significantly improve subjective sleep onset latency (SMD = 0.15, 95 % CI [0.01, 0.29], p = 0.04; n = 10 studies), subjective daytime dysfunction (SMD = 0.33, 95 % CI [0.16, 0.49], p < 0.001; n = 9 studies), and overall subjective sleep quality score (SMD = 0.43, 95 % CI [0.04, 0.83], p = 0.03; n = 12 studies). The findings indicate the potential use of L-theanine in the management of sleep disturbances; however, the lack of studies on "pure" L-theanine warrants further investigation. Future studies are needed to determine the adequate dose and duration of L-theanine supplementation for improving and maintaining sleep quality in healthy and clinical populations. Copyright © 2025 The Author(s). Published by Elsevier Ltd.. All rights reserved. DOI: 10.1016/j.smrv.2025.102076 PMID: 40056718 [Indexed for MEDLINE] Conflict of interest statement: Conflicts of interest A.B., A.M., and N.N. have received funding from the University of CanberraDiscovery Translation Grant that is registered with the University of Canberra research office (UC-DT510). All other authors declare no conflict of interest.

Minimal Influence of Formulated Nutritional Interventions on Sleep and Next-Morning Physical Performance, Cognitive Function, and Postural Sway in Adult Males: A Randomized, Placebo-Controlled, Crossover Study.

4. Int J Sport Nutr Exerc Metab. 2025 Feb 21;35(3):192-205. doi: 10.1123/ijsnem.2024-0148. Print 2025 May 1. Minimal Influence of Formulated Nutritional Interventions on Sleep and Next-Morning Physical Performance, Cognitive Function, and Postural Sway in Adult Males: A Randomized, Placebo-Controlled, Crossover Study. Morrison M(1)(2), Weakley J(1)(2)(3), Roach GD(4), Sargent C(4), Miller DJ(4), Nyman L(5), Gardiner C(1)(2), Munteanu G(1)(2), Pahnke MD(6), Halson SL(1)(2). Author information: (1)School of Behavioural and Health Sciences, Australian Catholic University, Brisbane, QLD, Australia. (2)Sports Performance, Recovery, Injury and New Technologies (SPRINT) Research Centre, Australian Catholic University, Brisbane, QLD, Australia. (3)Carnegie Applied Rugby Research (CARR) Centre, Institute of Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, United Kingdom. (4)Appleton Institute for Behavioural Science, Central Queensland University, Wayville, SA, Australia. (5)Gatorade Sports Science Institute, PepsiCo Inc., Valhalla, NY, USA. (6)Gatorade Sports Science Institute, PepsiCo Inc., Chicago, IL, USA. Athletes often experience poor sleep quality and quantity which may hinder physical performance and cognitive function. Presleep nutritional strategies may be an alternative to pharmacological interventions to improve sleep. The aim of this study was to examine the effect of two different doses of a nutritional intervention (both containing high Glycemic Index carbohydrate, whey, tryptophan, theanine, and 5'AMP) versus placebo on objective and subjective sleep, next-morning physical performance, cognitive function, and postural sway. Seventeen healthy, trained adult males completed three double-blind trials in a randomized, counterbalanced, crossover design. Participants were allocated to conditions using a Latin Square design. A (a) low-dose, (b) high-dose, or (c) placebo drink was provided 90 min before sleep each night. Polysomnography was used to measure objective sleep parameters. Cognitive function, postural sway, and subjective sleep quality were assessed 30 min after waking. Physical performance was assessed using a 10-min maximal effort cycling time trial each morning. All data were analyzed using linear mixed effects models and effect sizes were calculated using Cohen's d. This study was registered prospectively as a clinical trial with Australian New Zealand Clinical Trials Registry (registration number: NCT05032729). No significant main effects or improvements were observed in objective or subjective sleep parameters, physical performance, cognitive function, or postural sway. The low-dose intervention appeared to reduce N3 sleep duration compared with placebo (-13.6 min). The high-dose intervention appeared to increase N1 sleep duration compared with placebo (+7.4 min). However, the magnitude of changes observed were not likely to cause meaningful reductions in sleep quality and quantity. DOI: 10.1123/ijsnem.2024-0148 PMID: 39983739 [Indexed for MEDLINE]

The effects of L-theanine supplementation on the outcomes of patients with mental disorders: a systematic review.

5. BMC Psychiatry. 2024 Dec 4;24(1):886. doi: 10.1186/s12888-024-06285-y. The effects of L-theanine supplementation on the outcomes of patients with mental disorders: a systematic review. Moshfeghinia R(1)(2)(3), Sanaei E(4), Mostafavi S(5), Assadian K(5), Sanaei A(4), Ayano G(6). Author information: (1)Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran. rezamoshfeghinia@gmail.com. (2)Research Center for Psychiatry and Behavior Sciences, Shiraz University of Medical Sciences, Shiraz, Iran. rezamoshfeghinia@gmail.com. (3)Substance Abuse Research Center, Shiraz University of Medical Sciences, Shiraz, Iran. rezamoshfeghinia@gmail.com. (4)Student Research Committee, Shahid sadoughi university of medical sciences, Yazd, Iran. (5)Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran. (6)School of Population Health, Curtin University, Western, Australia. BACKGROUND: When utilized as an adjunct with antidepressants, antipsychotics, and other psychopharmacological drugs, certain amino acids, such as L-Theanine (LT), have shown potential effectiveness in enhancing the symptomatic outcomes of patients with mental disorders. Despite this, there is a lack of previous systematic reviews examining these associations. Therefore, we conducted a systematic review of randomized controlled trials examining these relationships. METHODS: A comprehensive systematic review was conducted, scouring six electronic databases (PubMed, Scopus, PsycINFO, Web of Science, CINAHL Complete, and Cochrane) from their inception up to June 2023, specifically focusing on randomized controlled trials that investigated the effects of LT supplementation on the outcomes of patients with mental health disorders. The Cochrane Risk of Bias Tool for Randomized Trials was employed to assess the quality of the included studies. RESULTS: Among the 419 publications identified, 11 studies from six countries - Israel, Iran, the USA, Japan, Australia, and Italy - were included in the final analysis. These studies covered a range of mental disorders, including schizophrenia, Attention-Deficit/Hyperactivity Disorder (ADHD), Obsessive-Compulsive Disorder (OCD), Major Depressive Disorder (MDD), sleep disorders, Generalized Anxiety Disorder (GAD), and Tourette syndrome. The findings demonstrated that LT supplementation reduced psychiatric symptoms more effectively than control conditions in individuals with schizophrenia, anxiety disorders, and ADHD. CONCLUSIONS: The findings from this systematic review suggest that LT supplementation significantly reduced psychiatric symptoms more effectively than control conditions in individuals with schizophrenia, anxiety disorders, and ADHD. However, further studies are essential to validate these findings, deepen the understanding of the observed effects, and explore the mechanisms underlying these associations. © 2024. The Author(s). DOI: 10.1186/s12888-024-06285-y PMCID: PMC11616108 PMID: 39633316 [Indexed for MEDLINE] Conflict of interest statement: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests. Clinical Trial Number: Not applicable.

Impact of L-theanine and L-tyrosine on markers of stress and cognitive performance in response to a virtual reality based active shooter training drill.

6. Stress. 2024 Jan;27(1):2375588. doi: 10.1080/10253890.2024.2375588. Epub 2024 Jul 8. Impact of L-theanine and L-tyrosine on markers of stress and cognitive performance in response to a virtual reality based active shooter training drill. McAllister MJ(1), Martaindale MH(2), Dillard CC(1), McCullough R(1). Author information: (1)Metabolic & Applied Physiology Laboratory, Department of Health & Human Performance, Texas State University, San Marcos, TX, USA. (2)ALERRT Center, Texas State University, San Marcos, TX, USA. Ingestion of L-theanine and L-tyrosine has been shown to reduce salivary stress biomarkers and improve aspects of cognitive performance in response to stress. However, there have been no studies to concurrently examine the impact of both L-theanine and L-tyrosine ingestion during a mental stress challenge (MSC) involving a brief cognitive challenge and a virtual reality based active shooter training drill. Thus, the purpose of this study was to determine the impact of ingestion of L-theanine and L-tyrosine on markers of stress and cognitive performance in response to a virtual reality active shooter drill and cognitive challenge. The cognitive challenge involved a Stroop challenge and mental arithmetic. Eighty subjects (age = 21 ± 2.6 yrs; male = 46; female = 34) were randomly assigned L-tyrosine (n = 28; 2000 mg), L-theanine (n = 25; 200 mg), or placebo (n = 27) prior to MSC exposure. Saliva samples, state-anxiety inventory (SAI) scales, and heart rate (HR) were collected before and after exposure to the MSC. Saliva was analyzed for stress markers α-amylase (sAA) and secretory immunoglobulin A (SIgA). The MSC resulted in significant increases in sAA, SIgA, HR, and SAI. Ingestion of L-theanine and L-tyrosine did not impact markers of stress. However, the L-tyrosine treatment demonstrated significantly lower missed responses compared to the placebo treatment group during the Stroop challenge. These data demonstrate that ingestion of L-theanine or L-tyrosine does not impact markers of stress in response to a MSC but may impact cognitive performance. This study was pre-registered as a clinical trial ("Impact of supplements on stress markers": NCT05592561). DOI: 10.1080/10253890.2024.2375588 PMID: 38975711 [Indexed for MEDLINE]

Dietary supplementation with Lactium and L-theanine alleviates sleep disturbance in adults: a double-blind, randomized, placebo-controlled clinical study.

7. Front Nutr. 2024 Jun 17;11:1419978. doi: 10.3389/fnut.2024.1419978. eCollection 2024. Dietary supplementation with Lactium and L-theanine alleviates sleep disturbance in adults: a double-blind, randomized, placebo-controlled clinical study. Lim SE(#)(1), Kim HS(#)(1), Lee S(1), Kang EY(2), Lim JH(2), Kim BY(2), Shin SM(#)(3), Baek Y(#)(1). Author information: (1)KM Data Division, Korea Institute of Oriental Medicine, Daejeon, Republic of Korea. (2)R&D Center, Chong Kun Dang Healthcare, Seoul, Republic of Korea. (3)Department of Internal Korean Medicine, College of Korean Medicine, Semyung University, Jecheon, Republic of Korea. (#)Contributed equally INTRODUCTION: The use of natural products for the treatment of sleep disturbances is increasing owing to the side effects and limitations of traditional sleep therapy. Moreover, recent studies have shown a significant correlation between sleep quality and gut microbiota composition. This study aimed to assess the impact of LTC-022, a commercially available dietary supplement containing Lactium and L-theanine, on enhancing sleep quality. METHODS: Forty participants experiencing sleep discomfort were enrolled in a double-blind randomized controlled trial, wherein they received LTC-022 or a placebo orally for 8 weeks. The effects of treatment on sleep quality were assessed using the Pittsburgh Sleep Quality Index and Insomnia Severity Index. To comprehensively evaluate changes in sleep patterns, various parameters were evaluated, including the time in bed (TIB), total sleep time (TST), sleep onset latency (SOL), sleep efficiency (SE), wake after sleep onset (WASO) counts, and bedtime. These parameters were derived from daily sleep logs recorded over the 8-week study period, categorized into weekdays and weekends. Stool samples were analyzed for microbiome composition. The V4 region of bacterial 16S rRNA genes was amplified using specific primers (515F and 806R) and targeted for analysis. Microbial diversity, including operational taxonomic units, the Shannon and Chao indices, the Firmicutes/Bacteroidetes (F/B) ratio, and the variety of bacterial taxa, was assessed. RESULTS: No significant differences were observed in sleep quality and insomnia scale characteristics between the two groups. In-depth analysis using sleep diaries showed that WASO counts after 8 weeks and bedtime after 4 weeks showed significant differences between the LTC-022 and control groups. In the LTC-022 group, significant differences were observed in the increase in TST, decrease in SOL, increase in SE, decrease in WASO counts, and earlier bedtime. Microbiome analysis revealed that the abundance of the genera Blautia and Ruminococcus increased in fecal samples from the LTC-022 group. CONCLUSION: These results suggest that continuous LTC-022 intake has a beneficial effect on maintaining sleep duration and an appropriate bedtime. Additionally, changes in the gut microbiota may be linked to changes in sleep patterns resulting from the consumption of Lactium and L-theanine. CLINICAL TRIAL REGISTRATION: https://cris.nih.go.kr/cris/search/detailSearch.do/22841, KCT0007750. Copyright © 2024 Lim, Kim, Lee, Kang, Lim, Kim, Shin and Baek. DOI: 10.3389/fnut.2024.1419978 PMCID: PMC11215043 PMID: 38953043 Conflict of interest statement: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Effect of a nutraceutical combination on sleep quality among people with impaired sleep: a randomised, placebo-controlled trial.

8. Sci Rep. 2024 Apr 5;14(1):8062. doi: 10.1038/s41598-024-58661-z. Effect of a nutraceutical combination on sleep quality among people with impaired sleep: a randomised, placebo-controlled trial. Gutiérrez-Romero SA(1), Torres-Narváez ES(1), Zamora-Gómez AC(2), Castillo-Castillo S(3), Latorre-Velásquez AL(3), Betancourt-Villamizar C(3), Mendivil CO(4)(5). Author information: (1)School of Medicine, Universidad de los Andes, Carrera 7 No 116-05, Of 413, 110111, Bogotá, Colombia. (2)Department of Neurology, Hospital Universitario Fundación Santa Fe de Bogotá, Bogotá, Colombia. (3)Research and Development, Team Foods Colombia, Bogotá, Colombia. (4)School of Medicine, Universidad de los Andes, Carrera 7 No 116-05, Of 413, 110111, Bogotá, Colombia. carlosolimpo@gmail.com. (5)Section of Endocrinology, Department of Internal Medicine, Hospital Universitario Fundación Santa Fe de Bogotá, Bogotá, Colombia. carlosolimpo@gmail.com. In this randomised, placebo-controlled trial, adults with impaired sleep (Pittsburgh Sleep Quality Index ≥ 5) were randomly assigned using a minimization algorithm to receive a formulation containing L-theanine plus lemon balm, valerian, and saffron extracts, or placebo, during 6 weeks. Objective sleep quality parameters were measured using an actigraphy device. We enrolled and randomised 64 individuals, 31 from the active group and 27 from the placebo group completed the 6 week follow-up. Mean sleep efficiency remained unmodified in the active group, and increased by 3% in the placebo group, the between-group difference in the change was not statistically significant (p = 0.49). Total sleep time also improved more with placebo (13.0 vs. 1.33 min, p = 0.66). Time wake after sleep onset (WASO) decreased more in the active group (4.6% vs. 2.4%), but the difference was not significant (p = 0.33). Mean PSQI decreased by 3.11 points (32.3%) in the active group, and by 3.86 points (39.5%) in the placebo group (p = 0.41). SF-36 increased more with placebo (+ 18.3 in active, + 32.1 in placebo, p = 0.68). Salivary cortisol remained unchanged in both groups. No serious adverse events were reported. Among adults with impaired sleep, a nutraceutical combination did not improve objective or subjective sleep parameters more than a placebo infusion. © 2024. The Author(s). DOI: 10.1038/s41598-024-58661-z PMCID: PMC10997602 PMID: 38580720 [Indexed for MEDLINE] Conflict of interest statement: This study was funded by Team Foods Colombia, but the sponsor was not involved in the study conduct or analysis, or in the decision to publish.

Effect of single or combined caffeine and L-Theanine supplementation on shooting and cognitive performance in elite curling athletes: a double-blind, placebo-controlled study.

9. J Int Soc Sports Nutr. 2023 Dec;20(1):2267536. doi: 10.1080/15502783.2023.2267536. Epub 2023 Oct 10. Effect of single or combined caffeine and L-Theanine supplementation on shooting and cognitive performance in elite curling athletes: a double-blind, placebo-controlled study. Yilmaz U(1), Buzdagli Y(2), Polat ML(3), Bakir Y(3), Ozhanci B(3), Alkazan S(3), Ucar H(4). Author information: (1)Hakkâri University, Department of Physical Education and Sports, Faculty of Education, Hakkâri, Turkey. (2)Erzurum Technical University, Department of Coaching Education, Faculty of Sport Sciences, Erzurum, Turkey. (3)Erzurum Technical University, Institute of Health Sciences, Erzurum, Turkey. (4)Atatürk University, Institute of Winter Sports and Sport Sciences, Erzurum, Turkey. PURPOSE: Previous studies have investigated the effect of single or combined caffeine (CAF) and L-theanine (THE) intake on attention performance. However, its effect on shooting performance and cognitive performance in a sport is unknown. The aim of this study was to investigate the hypothesis "Does single or combined CAF and THE supplementation have an effect on shooting and cognitive performance in elite curling athletes?." It is predicted that over the next decade, studies based on nutritional ergogenic supplements in the developing sport of curling will continue to increase, leading to a significant increase in studies examining the effects of CAF and THE supplementation, alone or in combination, on throwing and cognitive performance in elite curling athletes. METHODS: In this double-blind, randomized controlled crossover study, twenty-two elite national curling athletes (age 20.20 ± 1.61 and sports age 6.20 ± 0.51 years, height 174.10 ± 7.21 cm, BMI 21.80 ± 3.47 kg/m2) were randomly assigned to CAF (6 mg/kg single dose CAF), THE (6 mg/kg single dose THE), CAF*THE (6 mg/kg CAF and 6 mg/kg THE combined) and PLA (400 mg maltodextrin) groups at each of four sessions. 60 minutes after taking the supplement, the athletes were first given the Stroop test and then asked to shoot. RESULTS: Our main findings have shown that the performance of athletes in guard (F=3.452, P < .001, ηp2 = .842), draw (F=1.647, P < .001, ηp2 = .485), and take-out (F=3.121, P < .001, ηp2 = .743) shot styles significantly improved when comparing the combined intake of CAF and THE to the PLA. Regarding cognitive performance evaluation through the Stroop test, during the NR task (F=4.743, P = .001, ηp2 = .653), the combined intake of CAF and THE significantly improved reaction times compared to the intake of single CAF, THE, or PLA. The best reaction times during the CR and ICR (respectively; F=2.742, P = .004, ηp2 = .328; F = 1.632, P < .001, ηp2 = .625) tasks were achieved with the combined CAF and THE intake, showing a significant improvement compared to PLA. During the NER (F=2.961, P < .001, ηp2 = .741), task, the combined intake of CAF and THE significantly improved error rates compared to the intake of CAF, THE, or PLA single. The best accuracy rates during the CER and ICER (respectively; F=4.127, P < .001, ηp2 = .396; F=3.899, P < .001, ηp2 = .710) tasks were achieved with the combined CAF and THE intake, leading to a significant reduction in error rates compared to PLA. Based on these findings, it has been demonstrated in this study that the best shooting scores and cognitive performance were achieved, particularly with the combined intake of CAF and THE. CONCLUSIONS: Based on these findings, it has been demonstrated in this study that the best shooting scores and cognitive performance were achieved, particularly with the combined intake of CAF and THE. The combined use of these supplements has been found to be more effective on shooting and cognitive performance than their single use. DOI: 10.1080/15502783.2023.2267536 PMCID: PMC10566444 PMID: 37815006 [Indexed for MEDLINE] Conflict of interest statement: No potential conflict of interest was reported by the author(s).

Analysis of the Effects of Known Sleep-Support Supplements in Relation to Life Habits, Sleep Conditions, and Sleep Problems.

10. Nutrients. 2023 May 19;15(10):2377. doi: 10.3390/nu15102377. Analysis of the Effects of Known Sleep-Support Supplements in Relation to Life Habits, Sleep Conditions, and Sleep Problems. Imafuku F(1), Yamamoto K(1), Tanaka E(1), Aoki R(1), Nishino S(2). Author information: (1)Ezaki Glico Co., Ltd., Osaka 555-8502, Japan. (2)School of Medicine, Stanford University, Palo Alto, CA 94305, USA. Sleep is a crucial component of health, and insomnia is among the most common and vexing of life-habit-related disorders. While dietary sleep-support supplements can improve sleep, choosing an effective dietary supplement can be challenging for users due to the wide variety of options available and the varying effects experienced by different individuals. In this study, to identify new criteria for estimating the effects of dietary supplements, we examined the relationships among the dietary supplements, the pre-conditions (PCs; defined as the life habits and sleep conditions before supplementation), and the sleep problems of subjects before supplementation. An open, randomized, cross-over intervention trial enrolling 160 subjects was conducted to test the efficacy of each dietary supplement (Analysis 1) and the relationships among dietary supplements, the PCs, and sleep problems (Analysis 2). To this end, l-theanine (200 mg/day), γ-aminobutyric acid (GABA) (111.1 mg/day), Apocynum venetum leaf extract (AVLE) (50 mg/day), and l-serine (300 mg/day) were administered to subjects. Before the first intervention period, life habits and sleep conditions were surveyed to identify each subject's PCs. For each combination of supplements and sleep problems, PCs were compared between subjects whose sleep problems were improved and subjects whose sleep problems were not improved via supplementation. All the tested supplements were found to ameliorate sleep problems significantly (Analysis 1). In Analysis 2, the PCs specific to improved subjects were found to differ depending on the dietary supplements and sleep problems. In addition, subjects who consumed dairy products often showed improvement in their sleep problems with all the tested supplements. This study suggests the possibility of personalizing sleep-support supplementation based on personal life habits, sleep conditions, and sleep problems, in addition to the known efficacy of dietary supplements. DOI: 10.3390/nu15102377 PMCID: PMC10220724 PMID: 37242260 [Indexed for MEDLINE] Conflict of interest statement: There are no conflict to declare.

Effect of Alpha-S1-Casein Tryptic Hydrolysate and L-Theanine on Poor Sleep Quality: A Double Blind, Randomized Placebo-Controlled Crossover Trial.

11. Nutrients. 2022 Feb 3;14(3):652. doi: 10.3390/nu14030652. Effect of Alpha-S1-Casein Tryptic Hydrolysate and L-Theanine on Poor Sleep Quality: A Double Blind, Randomized Placebo-Controlled Crossover Trial. Thiagarajah K(1), Chee HP(1), Sit NW(1). Author information: (1)Department of Allied Health Sciences, Faculty of Science, University Tunku Abdul Rahman, Bandar Barat, Kampar 31900, Malaysia. This randomized, placebo-controlled, crossover and double-blind study investigates the effects of RLX2™ containing alpha-s1-casein tryptic hydrolysate and L-theanine in working adults affected by poor sleep quality. The supplement or placebo was randomly and blindly assigned to 39 subjects for four weeks and the changes in the subjective sleep assessment via the Pittsburgh Sleep Quality Index (PSQI), heart rate, blood pressure, salivary cortisol by high-performance liquid chromatography method and alpha power of awake electroencephalogram (EEG) were studied. The data were analyzed in two ways, by crossover and crossover summed up. The latter depicted that RLX2™ improved PSQI total score, sleep latency, sleep duration, sleep habitual efficiency, daytime dysfunction, and increased total and frontal alpha power significantly (p < 0.05). The supplement prolonged the total sleeping time by 45 min in the supplement receiving group compared to the placebo group (p < 0.001). However, only sleep duration and sleep habitual efficiency showed a profound effect in both analyses (p < 0.05). In conclusion, being given its beneficial effects without notable adverse events, it would be advantageous to use these nutraceutical ingredients to promote better sleep quality. Further studies with a larger number participants are warranted to support these findings. DOI: 10.3390/nu14030652 PMCID: PMC8838692 PMID: 35277011 [Indexed for MEDLINE] Conflict of interest statement: The authors declare that they have no conflicts of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

Use of Nutritional Supplements Based on L-Theanine and Vitamin B6 in Children with Tourette Syndrome, with Anxiety Disorders: A Pilot Study.

12. Nutrients. 2022 Feb 18;14(4):852. doi: 10.3390/nu14040852. Use of Nutritional Supplements Based on L-Theanine and Vitamin B6 in Children with Tourette Syndrome, with Anxiety Disorders: A Pilot Study. Rizzo R(1), Prato A(1)(2), Scerbo M(1), Saia F(1), Barone R(1), Curatolo P(3). Author information: (1)Child and Adolescent Neurology and Psychiatric Section, Department of Clinical and Experimental Medicine, Catania University, 95124 Catania, Italy. (2)Department of Cognitive Sciences, Psychology, Education and Cultural Studies, University of Messina, 98121 Messina, Italy. (3)Child Neurology and Psychiatry Unit, Systems Medicine Department, University of Rome Tor Vergata, 00133 Rome, Italy. BACKGROUND: Tourette syndrome (TS) is a neurodevelopmental disorder characterized by tics and co-occurring disorders. It has been suggested that anxiety occurs in 2-45% patients affected by Tourette syndrome. Despite dietary and nutritional factors have been found to affect a range of neurological conditions, no more studies have investigated the relationship between nutritional supplements and tics. OBJECTIVE: To evaluate the effectiveness of supplementation of both L-Theanine and Vitamin B6 in reducing tics and co-occurring disorders in a sample of youth with chronic tic disorder (CTD) or Tourette syndrome with anxiety symptoms. DESIGN: A open-label trial. Patients affected by Tourette syndrome were randomized to receive nutritional supplements based on L-Theanine and vitamin B6, or psychoeducation (PE). PARTICIPANTS: 34 children (30 boys and 4 girls) aged between 4 and 17 years affected by Tourette syndrome or chronic tic disorder, associated with anxiety symptoms. RESULTS: Patients in both groups showed a reduction in the severity of tic and anxiety symptoms. Supplementation with L-Theanine and vitamin B6 was significantly more effective than psychoeducation in reducing tics and co-occurring disorders, as measured by neuropsychological findings. CONCLUSIONS: Supplementation of both L-Theanine and Vitamin B6 may help in the treatment of tic disorders associated with anxious symptoms. Between-group differences in clinician-rated severity did reach statistical significance only for tics. Despite this finding, further placebo-controlled trials are needed. DOI: 10.3390/nu14040852 PMCID: PMC8875106 PMID: 35215501 [Indexed for MEDLINE] Conflict of interest statement: The authors declare no conflict of interest.

Treatment of refractory obsessive-compulsive disorder with nutraceuticals (TRON): a 20-week, open label pilot study.

13. CNS Spectr. 2022 Oct;27(5):588-597. doi: 10.1017/S1092852921000638. Epub 2021 Jun 21. Treatment of refractory obsessive-compulsive disorder with nutraceuticals (TRON): a 20-week, open label pilot study. Sarris J(1)(2), Byrne GJ(3)(4), Oliver G(2), Cribb L(2), Blair-West S(2), Castle D(5), Dean OM(6), Camfield DA(6), Brakoulias V(7)(8), Bousman C(9)(10)(11), Dowling N(2), Ee C(1), Murphy J(2), Menon R(2), Berk M(6)(12)(13), Chamoli S(3), Boschen M(14), Ng CH(2). Author information: (1)NICM Health Research Institute, Western Sydney University, Westmead, New South Wales, Australia. (2)The Melbourne Clinic, Department of Psychiatry, The University of Melbourne, Melbourne, Victoria, Australia. (3)University of Queensland Centre for Clinical Research, Royal Brisbane & Women's Hospital, Brisbane, Queensland, Australia. (4)Mental Health Service, Royal Brisbane & Women's Hospital, Brisbane, Queensland, Australia. (5)Centre for Complex Interventions, Department of Psychiatry, University of Toronto. (6)Institute for Mental and Physical Health and Clinical Translation (IMPACT), School of Medicine, Barwon Health, Deakin University, Geelong, Victoria, Australia. (7)Western Sydney Local Health District Mental Health Service, Sydney, New South Wales, Australia. (8)School of Medicine, Blacktown Hospital, Translational Health Research Institute (THRI), Clinical and Health Psychology Research Initiative (CaHPRI), Western Sydney University, Sydney, New South Wales, Australia. (9)Department of Medical Genetics, University of Calgary, Calgary, Alberta, Canada. (10)Department of Psychiatry, University of Calgary, Calgary, Alberta, Canada. (11)Department of Physiology & Pharmacology, University of Calgary, Calgary, Alberta, Canada. (12)Florey Institute for Neuroscience and Mental Health, Melbourne, Victoria, Australia. (13)Orygen, The National Centre of Excellence in Youth Mental Health and the Centre for Youth Mental Health, Melbourne, Victoria, Australia. (14)School of Applied Psychology, Griffith University, Gold Coast, Queensland, Australia. BACKGROUND: Obsessive-compulsive disorder (OCD) is often challenging to treat and resistant to psychological interventions and prescribed medications. The adjunctive use of nutraceuticals with potential neuromodulatory effects on underpinning pathways such as the glutamatergic and serotonergic systems is one novel approach. OBJECTIVE: To assess the effectiveness and safety of a purpose-formulated combination of nutraceuticals in treating OCD: N-acetyl cysteine, L-theanine, zinc, magnesium, pyridoxal-5' phosphate, and selenium. METHODS: A 20-week open label proof-of-concept study was undertaken involving 28 participants with treatment-resistant DSM-5-diagnosed OCD, during 2017 to 2020. The primary outcome measure was the Yale-Brown Obsessive-Compulsive Scale (YBOCS), administered every 4 weeks. RESULTS: An intention-to-treat analysis revealed an estimated mean reduction across time (baseline to week-20) on the YBOCS total score of -7.13 (95% confidence interval = -9.24, -5.01), with a mean reduction of -1.21 points per post-baseline visit (P ≤ .001). At 20-weeks, 23% of the participants were considered "responders" (YBOCS ≥35% reduction and "very much" or "much improved" on the Clinical Global Impression-Improvement scale). Statistically significant improvements were also revealed on all secondary outcomes (eg, mood, anxiety, and quality of life). Notably, treatment response on OCD outcome scales (eg, YBOCS) was greatest in those with lower baseline symptom levels, while response was limited in those with relatively more severe OCD. CONCLUSIONS: While this pilot study lacks placebo-control, the significant time effect in this treatment-resistant OCD population is encouraging and suggests potential utility especially for those with lower symptom levels. Our findings need to be confirmed or refuted via a follow-up placebo-controlled study. DOI: 10.1017/S1092852921000638 PMID: 34165060 [Indexed for MEDLINE]

Optimisation and Validation of a Nutritional Intervention to Enhance Sleep Quality and Quantity.

14. Nutrients. 2020 Aug 25;12(9):2579. doi: 10.3390/nu12092579. Optimisation and Validation of a Nutritional Intervention to Enhance Sleep Quality and Quantity. Halson SL(1), Shaw G(2), Versey N(3), Miller DJ(4), Sargent C(4), Roach GD(4), Nyman L(5), Carter JM(5), Baar K(6). Author information: (1)School of Behavioural and Health Sciences, Australian Catholic University, Banyo QLD 4014, Australia. (2)High Performance Unit, Swimming Australia, Brisbane QLD 4519, Australia. (3)Rowing Australia, Yarralumla ACT 2600, Australia. (4)Appleton Institute for Behavioural Science, Central Queensland University, Wayville 5034, Australia. (5)Gatorade Sport Science Institute, PepsiCo Global Research and Development-Life Sciences, Purchase, NY 10577, USA. (6)Departments of Neurobiology, Physiology & Behavior and Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA 95817, USA. BACKGROUND: Disturbed sleep may negatively influence physical health, cognitive performance, metabolism, and general wellbeing. Nutritional interventions represent a potential non-pharmacological means to increase sleep quality and quantity. OBJECTIVE: (1) Identify an optimal suite of nutritional ingredients and (2) validate the effects of this suite utilising polysomnography, and cognitive and balance tests. METHODS: The optimal and least optimal combinations of six ingredients were identified utilising 55 male participants and a Box-Behnken predictive model. To validate the model, 18 healthy, male, normal sleepers underwent three trials in a randomised, counterbalanced design: (1) optimal drink, (2) least optimal drink, or (3) placebo were provided before bed in a double-blinded manner. Polysomnography was utilised to measure sleep architecture. Cognitive performance, postural sway, and subjective sleep quality, were assessed 30 min after waking. RESULTS: The optimal drink resulted in a significantly shorter sleep onset latency (9.9 ± 12.3 min) when compared to both the least optimal drink (26.1 ± 37.4 min) and the placebo drink (19.6 ± 32.0 min). No other measures of sleep, cognitive performance, postural sway, and subjective sleep quality were different between trials. CONCLUSION: A combination of ingredients, optimised to enhance sleep, significantly reduced sleep onset latency. No detrimental effects on sleep architecture, subjective sleep quality or next day performance were observed. DOI: 10.3390/nu12092579 PMCID: PMC7551573 PMID: 32854375 [Indexed for MEDLINE] Conflict of interest statement: Financial support for this study was provided by the Gatorade Sports Science Institute, a division of PepsiCo, Inc. Authors Lara Nyman and James Carter are employed by PepsiCo, Inc. The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of PepsiCo, Inc.