Assessment of anti-stress, behavioural, and neurophysiological effects of L-theanine: A randomised, double-blind, placebo-controlled, crossover trial
Assessment of anti-stress, behavioural, and neurophysiological effects of L-theanine: A randomised, double-blind, placebo-controlled, crossover trial in healthy adults
Swinburne University of Technology
34 participants
Dec 11, 2013
Interventional
Conditions
Summary
This study is a randomised, double-blind, placebo-controlled, crossover trial. A total of 34 healthy right-handed male and female participants aged 18 to 40 years old will take part in the study. Participants will be required to attend three sessions. The first visit is a screening and practice session, assessing eligibility and familiarising participants with cognitive tasks. Finally, structural brain information will be obtained during an MRI scan. Subsequently, two testing days will be conducted a minimum of 48 hours apart. Participants will be assigned to a treatment sequence, such that one of each treatment is received across the two testing days. At testing days participants will receive a standardised lunch upon arrival, followed by a 30-minute break, then undergo baseline assessment of stress, mood, and cognitive function. After baseline assessment, treatment will be administered. 30-minutes after administration of treatment, participants will once again undergo assessment of stress, mood, and cognitive function, followed by recording of brain activity during rest and an attention task using magnetoencephalography (MEG). After this, the assessment of stress, mood, and cognitive function will be conducted a third time. Participants will consume all interventions orally as a drink of approximately 430 ml (14.5 fl oz). Both active and vehicle control treatments contain identical ingredients of sweeteners (crystalline fructose and sucralose) and preservatives (sodium benzoate, potassium sorbate) , gum acacia and malic acid. In addition, the active treatment contains L-Theanine (200 mg, L-Tea-Active), L-Alpha Glycerylphosphorylcholine (Alpha GPC; 25 mg)), phosphatidylserine (1mg) and chamomile (10 mg).
Eligibility
Inclusion Criteria8
- Male or female.
- Aged 18-40 years.
- Willing and able to provide written informed consent.
- Understands and is willing and able to comply with all study procedures.
- Fluent in written and spoken English.
- Are in good general health with no history of psychiatric disease.
- Must have normal, or corrected to normal vision
- Participants must be right handed. This is for ease of analysis of the MEG data. There are hemispheric differences in terms of structure and function between right and left handed individuals that prove to be problematic when analysing the output. Given that this investigation will employ a method where participants need to press buttons as a response (in turn involving the motor cortex), it is wise to use an all right handed population.
Exclusion Criteria11
- Females who are pregnant or breast-feeding
- Individuals currently taking medication (other than the contraceptive pill).
- Any significant concurrent illness including any bleeding disorders, heart conditions, diabetes, glaucoma, high blood pressure or osteoporosis.
- Individuals who suffer from Diabetes Mellitus.
- Any known or suspected food allergies (this would cover all ingredients in the investigational product).
- Smokers and users of recreational drugs (except alcohol and other food grade actives)
- Have participated in any other study involving an investigational product in the last 4 weeks.
- Metal implants (for safety in MRI and MEG)
- Have undergone an MRI scan within the previous 7 days
- Individuals who suffer from claustrophobia
- Individuals who are colour blind
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Interventions
The present study will test the anti-stress, cognitive, and neurophysiological effects of acute L-theanine, Chamomile, Alpha GPC and phospholipid administration when compared to a placebo (vehicle control), using a randomised, controlled, double-blind, crossover design. Participants will be required to attend three sessions. The first visit is a screening and practice session, assessing eligibility and familiarising participants with cognitive tasks. Finally, structural brain information will be obtained during an MRI scan. Subsequently, two testing days will be conducted a minimum of 48 hours apart. Participants will be assigned to a treatment sequence, such that one of each treatment is received across the two testing days. At testing days participants will receive a standardised lunch upon arrival, followed by a 30-minute break, then undergo baseline assessment of stress, mood, and cognitive function. After baseline assessment, treatment will be administered. 30-minutes after administration of treatment, participants will once again undergo assessment of stress, mood, and cognitive function, followed by recording of brain activity during rest and an attention task using magnetoencephalography (MEG). After this, the assessment of stress, mood, and cognitive function will be conducted a third time. Participants will consume all interventions orally as a drink of approximately 430 ml (14.5 fl oz). Both active and vehicle control treatments contain identical ingredients of sweeteners (crystalline fructose and sucralose) and preservatives (sodium benzoate, potassium sorbate) , gum acacia and malic acid. In addition, the active treatment contains L-Theanine (200 mg, L-Tea-Active), L-Alpha Glycerylphosphorylcholine (Alpha GPC; 25 mg)), phosphatidylserine (1mg) and chamomile (10 mg).
Locations(1)
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ACTRN12614000826640