Anti-Stress, Behavioural and Magnetoencephalography Effects of an L-Theanine-Based Nutrient Drink: A Randomised, Double-Blind, Placebo-Controlled, Crossover Trial

source extracted confidence: high 2026-04-09
#adolescent #adult #affect #alpha-rhythm #anxiety

Anti-Stress, Behavioural and Magnetoencephalography Effects of an L-Theanine-Based Nutrient Drink: A Randomised, Double-Blind, Placebo-Controlled, Crossover Trial

White et al., 2016 | Nutrients | Rct

Citation

White David J, de Klerk Suzanne, ... Scholey Andrew B. Anti-Stress, Behavioural and Magnetoencephalography Effects of an L-Theanine-Based Nutrient Drink: A Randomised, Double-Blind, Placebo-Controlled, Crossover Trial. Nutrients. 2016-Jan-19;8(1). doi:10.3390/nu8010053

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.

Key Findings

These findings further support the anti-stress effects of L-theanine.

Outcomes Measured

  • anxiety
  • cortisol levels

Population

Field Value
Population See abstract
Sample Size See abstract
Age Range aged 18-40
Condition anxiety

MeSH Terms

  • Adolescent
  • Adult
  • Affect
  • Alpha Rhythm
  • Anxiety
  • Beverages
  • Cognition
  • Cross-Over Studies
  • Double-Blind Method
  • Female
  • Glutamates
  • Healthy Volunteers
  • Humans
  • Hydrocortisone
  • Magnetoencephalography
  • Male
  • Rest
  • Saliva
  • Stress, Psychological
  • Tea
  • Time Factors
  • Young Adult

Evidence Classification

  • Level: Rct
  • Publication Types: Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't
  • Vertical: l-theanine-anxiety

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09