title: Anti-Stress, Behavioural and Magnetoencephalography Effects of an L-Theanine-Based Nutrient Drink: A Randomised, Double-Blind, Placebo-Controlled, Crossover Trial.
abstract: L-theanine (γ-glutamylethylamide) is an amino acid found primarily in the green tea plant. This study explored the effects of an L-theanine-based nutrient drink on mood responses to a cognitive stressor. Additional measures included an assessment of cognitive performance and resting state alpha oscillatory activity using magnetoencephalography (MEG). Thirty-four healthy adults aged 18-40 participated in this double-blind, placebo-controlled, balanced crossover study. The primary outcome measure, subjective stress response to a multitasking cognitive stressor, was significantly reduced one hour after administration of the L-theanine drink when compared to placebo. The salivary cortisol response to the stressor was reduced three hours post-dose following active treatment. No treatment-related cognitive performance changes were observed. Resting state alpha oscillatory activity was significantly greater in posterior MEG sensors after active treatment compared to placebo two hours post-dose; however, this effect was only apparent for those higher in trait anxiety. This change in resting state alpha oscillatory activity was not correlated with the change in subjective stress response or the cortisol response, suggesting further research is required to assess the functional relevance of these treatment-related changes in resting alpha activity. These findings further support the anti-stress effects of L-theanine.
authors.affiliation: Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn VIC 3122, Australia. dawhite@swin.edu.au.
authors.forename: David J
authors.initials: DJ
authors.lastname: White
authors.affiliation: Division of Pharmacology, Utrecht University, 3508 TC Utrecht, The Netherlands. suzanne_dk@hotmail.com.
authors.forename: Suzanne
authors.initials: S
authors.lastname: de Klerk
authors.affiliation: Brain and Psychological Sciences Research Centre, Swinburne University of Technology, Hawthorn VIC 3122, Australia. wwoods@swin.edu.au.
authors.forename: William
authors.initials: W
authors.lastname: Woods
authors.affiliation: Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn VIC 3122, Australia. sgondalia@swin.edu.au.
authors.forename: Shakuntla
authors.initials: S
authors.lastname: Gondalia
authors.affiliation: HealthGuidance, Inc., Santa Monica, CA 90403-5104, USA. chris@healthguidance.us.
authors.forename: Chris
authors.initials: C
authors.lastname: Noonan
authors.affiliation: Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn VIC 3122, Australia. andrew@scholeylab.com.
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Scholey
mesh_terms: D000293:Adolescent; D000328:Adult; D000339:Affect / Q000187:drug effects; D000513:Alpha Rhythm / Q000187:drug effects; D001007:Anxiety / Q000378:metabolism; D001628:Beverages; D003071:Cognition / Q000187:drug effects; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D005971:Glutamates / Q000494:pharmacology*; D064368:Healthy Volunteers; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism; D015225:Magnetoencephalography; D008297:Male; D012146:Rest / Q000502:physiology; D012463:Saliva / Q000737:chemistry; D013315:Stress, Psychological / Q000188:drug therapy* / Q000503:physiopathology; D013662:Tea / Q000737:chemistry; D013997:Time Factors; D055815:Young Adult
chemical_list: D005971:Glutamates; D013662:Tea; C026166:theanine; D006854:Hydrocortisone
keywords: ">l-theanine; alpha activity; cognition; cortisol; mood; stress