Tea Components, Mental Stress and Blood Pressure

Not Applicable

Completed

• Conditions: Healthy

• Registration Number: NCT02298530
• Lead Sponsor: Unilever R&D

Brief Summary

Assess the effects of adding theanine to a caffeinated beverage on changes in blood pressure during acute mental stress.

Detailed Description

Caffeine and (mental) stress can increase blood pressure. In a typical everyday and/or work environment they commonly coincide. Tea has the reputation of being a relaxing drink. L-theanine is an amino acid found almost exclusively in tea. In a previous study it was shown that caffeine increased blood pressure, while theanine antagonised these effects. In the current study the effect of theanine to a placebo on blood pressure are directly compared.

Study Timeline

• Study First Submitted: 2014-11-12
• Study First Submitted QC: 2014-11-19
• Study First Posted: 2014-11-24
• Study Start: 2015-03
• Primary Completion: 2015-10
• Study Completion: 2015-11
• Status Verified: 2015-12
• Last Update Submitted: 2015-12-03
• Last Update Posted: 2015-12-04

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 56

Inclusion Criteria

• Apparently healthy males and females
• Women taking the contraceptive pill
• 18-45 years of age
• BMI 20-30 kg/m2
• Normal or corrected vision
• Low caffeine consumers (<100mg/day)
• Non smokers and having been a non-smoker for > 6 months
• Fluent English
• Normotensive (>90/60 <140/90 mmHg)

Exclusion Criteria

• Significant current or medical history of cardiovascular disease
• Low or high STAI trait score in the opinion of the PI
• Known sensitivity to caffeine or theanine
• Colour blindness
• Alcohol consumption above 14/21 units female/male resp. per week
• Weight loss diet > 10% of bodyweight in the previous year
• Anyone with a dependency on PI or staff of Department of Epidemiology and Public Health or being an employee of Unilever
• Reported participation in another biomedical study < 3 months before screening

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
Systolic blood pressure during stress	Between 30-45 minutes after test product intake	Systolic blood pressure during acute mental stress

Secondary Outcome Measures

Name	Time	Method
Diastolic blood pressure during stress	Between 30-45 minutes after test product intake	Diastolic blood pressure during acute mental stress
Systolic blood pressure after stress	Between 45-60 minutes after test product intake	Systolic blood pressure immediately after acute mental stress
Diastolic blood pressure after stress	Between 45-60 minutes after test product intake	Diastolic blood pressure immediately after acute mental stress
STAI before and immediately after stress	-15 and 45 relative to test product intake	Self-reported mental state: State-Trait Anxiety Inventory
UWIST before and immediately after stress	-10, 45 minutes relative to test product intake	Self-reported mental state: University Of Wales Institute of Science and Technology mood adjective questionnaire

Trial Locations

Locations (1)

University College London; 🇬🇧 London, United Kingdom