Clinical trial NCT02298530: Tea Components, Mental Stress and Blood Pressure
Official title: A Study to Determine the Acute Effects of a Tea Component on Blood Pressure and Mental Stress Challenge
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Healthy
Lead sponsor: Unilever R&D
Sponsor class: INDUSTRY
Collaborators: name: University College, London
First posted: 2014-11-24
Enrollment: 56
Sex: ALL
Minimum age (years): 18
Maximum age (years): 45
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: TREATMENT

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.

Eligibility criteria: 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

Primary outcomes:
measure: Systolic blood pressure during stress
timeFrame: Between 30-45 minutes after test product intake
Secondary outcomes:
measure: Diastolic blood pressure during stress
timeFrame: Between 30-45 minutes after test product intake
measure: Systolic blood pressure after stress
timeFrame: Between 45-60 minutes after test product intake
measure: Diastolic blood pressure after stress
timeFrame: Between 45-60 minutes after test product intake
measure: STAI before and immediately after stress
timeFrame: -15 and 45 relative to test product intake
measure: UWIST before and immediately after stress
timeFrame: -10, 45 minutes relative to test product intake
Other outcomes:
measure: Cortisol in saliva before and immediately after stress
timeFrame: -5, 45 min relative to test product intake
measure: Heart rate during stress
timeFrame: Between 30-45 minutes after test product intake
measure: Heart rate after stress
timeFrame: Between 45-60 minutes after test product intake
measure: Heart rate variability during stress
timeFrame: Between 30-45 minutes after test product intake
measure: Heart rate variability after stress
timeFrame: Between 45-60 minutes after test product intake
measure: Performance STROOP
timeFrame: Between 30-45 minutes after test product intake
measure: Performance mirror tracing
timeFrame: Between 30-45 minutes after test product intake
measure: Systolic blood pressure, free living phase
timeFrame: Between 80-270 minutes after test product intake
measure: Diastolic blood pressure, free living phase
timeFrame: Between 80-270 minutes after test product intake
measure: Cortisol, free living phase
timeFrame: 140, 200 and 260 minutes after test product intake
measure: STAI, free living phase
timeFrame: 140, 200 and 260 minutes after test product intake
measure: UWIST, free living phase
timeFrame: 140, 200 and 260 minutes after test product intake
measure: Pulse pressure during stress
timeFrame: Between 30-45 minutes after test product intake
measure: Pulse pressure after stress
timeFrame: Between 45-60 minutes after test product intake
measure: Mental wellbeing
timeFrame: 7 consecutive days prior to the lab sessions
measure: Physical activity
timeFrame: 7 consecutive days prior to the lab sessions
measure: STAI screening
timeFrame: Screening
measure: CES-D
timeFrame: Screening
measure: CISS
timeFrame: Screening
measure: loneliness
timeFrame: Screening
measure: Perceived stress
timeFrame: Screening
Locations:
city: London
country: United Kingdom
facility: University College London
Study officials:
affiliation: UCL, Epidemiology & Public Health, London
name: Mark Hamer, Dr
role: PRINCIPAL_INVESTIGATOR
References: