None listed
Conditions
Brief summary
This research project is aiming to determine the effects of green tea and combinations of potential active components of green tea (caffeine and catechins) on cognitive function and mood. This project will assess the effectiveness of green tea extract and different fractions of green tea extract on cognitive function (primarily attention) and mood measures. The plasma levels of several potential active constituents of green tea will also be monitored. Subjects will be required to attend five testing sessions (and one practice session). Subjects will take one intervention (administered in capsule format) at each session. 1. Whole green tea extract standardised with regard to caffeine and catechins (‘GTE’). Extract to deliver 40 mg caffeine per dose. 2. 40 mg synthetic caffeine (‘caffeine’) 3. Decaffeinated green tea extract (‘Decaff-GTE’) standardised with regard to catechins 4. Catechins alone i.e. without any other components of green tea extract (‘catechins’) 5. Placebo
Interventions
The investigation will employ a single centre, double-blind, placebo controlled, five-period crossover design with a 7-day washout period.
Participants will be required to attend one practice session followed by five testing sessions.
During the practice session particpants will sign the consent form and be familiarised with the mood scales and cognitive tasks.
The testing sessions will see participants taking one of four interventions:
1) Whole green tea extract standardised with regard to
The investigation will employ a single centre, double-blind, placebo controlled, five-period crossover design with a 7-day washout period. Participants will be required to attend one practice session followed by five testing sessions. During the practice session particpants will sign the consent form and be familiarised with the mood scales and cognitive tasks. The testing sessions will see participants taking one of four interventions: 1) Whole green tea extract standardised with regard to caffeine and catechins (‘GTE’). Extract to deliver 40 mg caffeine per dose,170 mgs catechins. 2) 40 mg synthetic caffeine (‘caffeine’) 3) Decaffeinated green tea extract (‘Decaff-GTE’) standardised with regard to catechins. Extract to deliver 0.12 mgs caffeine; 170 mgs catechins, 4) Catechins alone i.e. without any other components of green tea extract (‘catechins’). Extract to deliver 185 mgs catechins . 5) Placebo All five treatments will be administered as capsules and will be matched for colour, smell and taste Participants will be randomly allocated to receive either treatment (1) or (2) or (3) or (4) or (5) on their first testing day. This will be done by a randomised computer number sequence generator. Over the course of the investigation, they will complete all five treatments with treatment order counterbalanced across participants. A disinterested third party will be responsible for the blinding procedure. On the testing days subjects will provide baseline blood and saliva samples then undergo baseline mood and cognitive assessment. The day’s treatment will be administered at 9.00 am +/- 30 min) followed exactly 30 min and 120 min later by the same mood and cognitive assessment (using parallel forms of stimuli). Final blood and saliva samples will be taken and subjects will leave the laboratory. At the end of the final visit subjects will be fully debriefed before leaving the laboratory. There will be a seven day washout period between each testing session
Sponsors
GlaxoSmithKline Nutritional Healthcare
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Blinded (masking used)
Eligibility
Sex/Gender
All
Age
18 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
People who meet the following inclusion criteria will be included in the trial: 1. Male or female. 2. Aged 18-40 years. 3. Willing and able to provide written informed consent. 4. Understands and is willing and able to comply with all study procedures. 5. Are in good general health with no history of psychiatric disease. 6. Regular caffeine consumers (between 1-4 cups of coffee per day most days) 7. Must have corrected to normal vision
Exclusion criteria
Subjects who display any of the following will be excluded from the trial: 1.Females who are pregnant/lactating and/or not using a medically approved form of contraception. 2. Any significant concurrent illness including any bleeding disorders, heart conditions, diabetes, glaucoma, high blood pressure or osteoporosis. 3. Individuals who suffer from Diabetes Mellitus or diagnosed with Phenylketonuria (PKU). 4. Any known or suspected food allergies (this would cover all ingredients in the investigational product). 5. Susceptible to any unwanted side-effects of caffeine, such as reduction in sleep quality. 6. Smokers and users of recreational drugs (except alcohol and other food grade actives) 7. Have participated in any other study involving an investigational product in the last 4 weeks.
Outcome results
None listed