Healthy
Conditions
Keywords
Black tea, Flow Mediated Dilation, Vascular function, India
Brief summary
This study examines the effect of 1800 mg/day standardized Brooke Bond black tea extract, equivalent to 400 mg flavonoids, on Flow Mediated Dilation in healthy Indian males.
Detailed description
Flow mediated dilation (FMD) is a non-invasive measurement technique performed using ultrasound equipment to measure hyperaemia induced dilation of blood vessels. Evidence from prospective studies suggests that FMD is independently inversely associated with cardiovascular events.
Interventions
OTHERNutrition intervention study with a black tea extract
Tea extract: 1800 mg/day standardized Brooke Bond black tea extract equivalent to 400 mg flavonoids dissolved in 240 ml hot water. Products will be consumed for 8 days. On measurement days tea will be given to the subjects as a single acute dose and 2 grams of sugar will be added. On day 2-7 subjects will consume 3 cups or tea, each prepared with 800 mg product in 80 ml of boiling water and sugar added to subject's taste. First cup of tea will be taken as morning tea, 2nd at breakfast and 3rd in the evening. No milk will be added.
OTHERNutrition intervention study with a control
Control: 1800 mg/day of a powder that gives a flavoured beverage with a color similar to black tea dissolved in 240 ml hot water. Products will be consumed for 8 days. On measurement days control will be given to the subjects as a single acute dose and 2 grams of sugar will be added. On day 2-7 subjects will consume 3 cups of control, each prepared with 800 mg product in 80 ml of boiling water and sugar added to subject's taste. First cup of tea will be taken as morning tea, 2nd at breakfast and 3rd in the evening. No milk will be added.
Sponsors
Lotus Labs Pvt. Ltd, Bangalore, India
Clumax Diagnostics, Bangalore, India
Quipu S.r.l, Pisa, Italy
Unilever R&D
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
MALE
Age
30 Years to 50 Years
Healthy volunteers
Yes
Inclusion criteria
* Male volunteers aged between \>\_30 \_\< 50 years of age * Body Mass Index (BMI) of \>\_18 and \_\< 25.0 kg/m2 * Systolic blood pressure \>\_140 and \>\_100 mmHg and diastolic blood pressure \< 90 and \> 70 mmHg * Subjects who consume \_\< 2 cups of coffee per day * Subjects who drink tea regularly (\>\_ 2 cups per day) * Apparently healthy, with no reported medical condition which might affect the assessment as judged by the study physician or/and PI * No prescribed medical treatment that may affect study parameters as judged by the Study Physician * Subject willing to abstain from alcohol on day before and on the day of assessment * Willing to sign the informed consent form
Exclusion criteria
* Smokers and/or tobacco chewers * Those who consume regular alcohol (\> 160 ml of alcohol per week) * Reported intense sport activities \> 10h/week * Participating in any other clinical study concurrently or if participated in any study during 2 months preceding the screening visit
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 'Acute-upon-chronic Effect' of Tea vs Control | Baseline day 1 to 2 hours post consumption on day 8. | Change in flow mediated dilation (FMD) due to tea consumption when compared to control. FMD measurement included the following steps: * 1 minute base scan to measure the baseline diameter of artery (baseline) * 5 minutes of forearm occlusion at 300±30 mmHg, just below the elbow 2-5 cm from antecubital crease * 4 minutes FMD scan, which started immediately after release of the occlusion (reactive hyperaemia stage) FMD was calculated as maximal percentage change in diameter of the artery above the baseline value after the release of the occlusion |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Acute Effect of Tea vs Control | From baseline on day 1 to 2 hours post consumption on day 1 | Change in flow mediated dilation due to tea consumption when compared to control. FMD measurement included the following steps: * 1 minute base scan to measure the baseline diameter of artery (baseline) * 5 minutes of forearm occlusion at 300±30 mmHg, just below the elbow 2-5 cm from antecubital crease * 4 minutes FMD scan, which started immediately after release of the occlusion (reactive hyperaemia stage) FMD was calculated as maximal percentage change in diameter of the artery above the baseline value after the release of the occlusion |
| Chronic Effect of Tea vs Control | From baseline at day 1 to baseline on day 8 | Change in flow mediated dilation (FMD) due to tea consumption when compared to control. FMD measurement included the following steps: * 1 minute base scan to measure the baseline diameter of artery (baseline) * 5 minutes of forearm occlusion at 300±30 mmHg, just below the elbow 2-5 cm from antecubital crease * 4 minutes FMD scan, which started immediately after release of the occlusion (reactive hyperaemia stage) FMD was calculated as maximal percentage change in diameter of the artery above the baseline value after the release of the occlusion |
Countries
India
Participant flow
Recruitment details
Forty five subjects were invited for screening. Two subjects did not come for the screening, three subjects were not willing to participate and three subjects did not fulfil the inclusion criteria. Of the 37 subjects that fulfilled all inclusion an exclusion criteria 30 were invited to participate.
Pre-assignment details
Thirty subjects meeting all criteria were randomised over the two arms
Participants by arm
| Arm | Count |
|---|---|
| Study Population All participants who were randomised | 30 |
| Total | 30 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Run in on Placebo | Adverse Event | 1 | 0 |
Baseline characteristics
| Characteristic | Study Population |
|---|---|
| Age, Continuous Age | 36 years |
| Body Mass Index | 23.2 kg/m^2 |
| Region of Enrollment India | 30 participants |
| Sex: Female, Male Female | 0 Participants |
| Sex: Female, Male Male | 30 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — | — / — |
| other Total, other adverse events | 1 / 29 | 1 / 29 | 3 / 30 |
| serious Total, serious adverse events | 0 / 29 | 0 / 29 | 0 / 30 |
Outcome results
Primary
'Acute-upon-chronic Effect' of Tea vs Control
Change in flow mediated dilation (FMD) due to tea consumption when compared to control. FMD measurement included the following steps: * 1 minute base scan to measure the baseline diameter of artery (baseline) * 5 minutes of forearm occlusion at 300±30 mmHg, just below the elbow 2-5 cm from antecubital crease * 4 minutes FMD scan, which started immediately after release of the occlusion (reactive hyperaemia stage) FMD was calculated as maximal percentage change in diameter of the artery above the baseline value after the release of the occlusion
Time frame: Baseline day 1 to 2 hours post consumption on day 8.
Population: Per protocol based on the full data set excluding one subject who did produce relevant data (AE) and three subjects who were removed during blind review (operator comments, hypertension and increase in body weight). Single data points were removed for 6 subjects (all single data points) based on operator comments.
| Arm | Measure | Value (LEAST_SQUARES_MEAN) |
|---|---|---|
| Tea Beverage | 'Acute-upon-chronic Effect' of Tea vs Control | 8.03 percentage of change in diameter |
| Control Beverage | 'Acute-upon-chronic Effect' of Tea vs Control | 9.03 percentage of change in diameter |
Comparison: Null hypothesis: no difference between Tea and Control.p-value: 0.0995% CI: [-2.16, 0.17]Mixed Models Analysis
Secondary
Acute Effect of Tea vs Control
Change in flow mediated dilation due to tea consumption when compared to control. FMD measurement included the following steps: * 1 minute base scan to measure the baseline diameter of artery (baseline) * 5 minutes of forearm occlusion at 300±30 mmHg, just below the elbow 2-5 cm from antecubital crease * 4 minutes FMD scan, which started immediately after release of the occlusion (reactive hyperaemia stage) FMD was calculated as maximal percentage change in diameter of the artery above the baseline value after the release of the occlusion
Time frame: From baseline on day 1 to 2 hours post consumption on day 1
Population: Per protocol based on the full data set excluding one subject who did produce relevant data (AE) and three subjects who were removed during blind review (operator comments, hypertension and increase in body weight). Single data points were removed for 6 subjects (all single data points) based on operator comments.
| Arm | Measure | Value (LEAST_SQUARES_MEAN) |
|---|---|---|
| Tea Beverage | Acute Effect of Tea vs Control | 8.44 percent change in flow mediated dilation |
| Control Beverage | Acute Effect of Tea vs Control | 8.82 percent change in flow mediated dilation |
Comparison: Null hypothesis: no difference between Tea and Control.p-value: 0.795% CI: [-2.44, 1.66]Mixed Models Analysis
Secondary
Chronic Effect of Tea vs Control
Change in flow mediated dilation (FMD) due to tea consumption when compared to control. FMD measurement included the following steps: * 1 minute base scan to measure the baseline diameter of artery (baseline) * 5 minutes of forearm occlusion at 300±30 mmHg, just below the elbow 2-5 cm from antecubital crease * 4 minutes FMD scan, which started immediately after release of the occlusion (reactive hyperaemia stage) FMD was calculated as maximal percentage change in diameter of the artery above the baseline value after the release of the occlusion
Time frame: From baseline at day 1 to baseline on day 8
Population: Per protocol based on the full data set excluding one subject who did produce relevant data (AE) and three subjects who were removed during blind review (operator comments, hypertension and increase in body weight). Single data points were removed for 6 subjects (all single data points) based on operator comments.
| Arm | Measure | Value (LEAST_SQUARES_MEAN) |
|---|---|---|
| Tea Beverage | Chronic Effect of Tea vs Control | 9.19 Percentage change in flow mediated dilat |
| Control Beverage | Chronic Effect of Tea vs Control | 9.39 Percentage change in flow mediated dilat |
Comparison: Null hypothesis: no difference between Tea and Control.p-value: 0.6695% CI: [-1.15, 0.75]Mixed Models Analysis