ong-term effects of regular consumption of tea-derived flavonoids on endothelial function, blood pressure and cardiovascular disease risk: a randomized controlled trial
- Conditions
- Cardiovascular diseaseCardiovascular - Diseases of the vasculature and circulation including the lymphatic systemDiet and Nutrition - Other diet and nutrition disorders
- Registration Number
- ACTRN12607000543482
- Lead Sponsor
- niveristy of Western Australia
- Brief Summary
Not available
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- Withdrawn
- Sex
- All
- Target Recruitment
- 100
Age at start of the study > 35 and < 75 years.
Body Mass Index (BMI) >19 and < 35 kg/m2.
4 hour day time ambulatory systolic blood pressure >120 and < 151 mmHg, and ambulatory diastolic blood pressure < 100 mmHg at screening visit.
No use of supplements 4 weeks prior to and during the study.
Haematology within the normal reference range.
Total cholesterol < 6.5 mmol/L, plasma creatinine and liver enzymes within normal reference range.
Fasting blood glucose < 6.5 mmol/L and potassium within normal reference range.
Willing to replace use of aspirin and aspirin-like painkillers (e.g. Ibuprofen) by paracetamol 4 weeks prior to and during the study.
Agreeing to be informed about medically relevant personal test-results.
Having access to a general practitioner (GP).
Informed consent signed.
Being an employee or student of the University of Western Australia.
A recorded history or current diabetes or a recorded history of metabolic diseases, chronic gastrointestinal disorders, cardiovascular, malignancies, renal disease or psychiatric disorders.
Currently on a medically prescribed diet, or slimming diet or actively trying to lose weight.
Subjects with pulse <50 or >100 beats per minute.
Reported intense sporting activities > 10 hours per week.
Subjects who are taking more than three different classes of antihypertensive medications or who take anti-hypertensive medication that may effect the bioavailability of the test products and not able or willing to stop taking them.
Use of systemic antibiotics in the period of 1 month prior to the study.
Reported intolerance or allergy to test products.
Reported lactating, pregnant or wishing to become pregnant during the study.
Reported weight change ± 10% during a period of 6 months prior to the study.
Alcohol intake > 200 g alcohol/wk for women and > 300 g alcohol/wk for men.
Combined tea and coffee intake < than 2 cups per day.
Reported participation in another biomedical study 3 months before the start or during the study.
The habit of smoking cigarettes during the past year.
Reported participation in night shift work during the study period.
Study & Design
- Study Type
- Interventional
- Study Design
- Not specified
- Primary Outcome Measures
Name Time Method Endothelial function (Brachial artery flow-mediated dilatation assessed using ultrasound measurement)[At baseline, 3 months and 6 months];24 hour ambulatory blood pressure in the whole population and a sub-group analysis including only those participants with above optimal (>125 mm Hg or 80 mm Hg) 24 hour systolic or diastolic blood pressure.[At baseline, 3 months and 6 months]
- Secondary Outcome Measures
Name Time Method Fasting serum total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol and triglycerides using routine methods within the core clinical laroratory at Royal Perth Hospital.[At baseline, 3 months and 6 months];Fasting serum glucose and insulin using routine methods within the core clinical laroratory at Royal Perth Hospital[At baseline, 3 months and 6 months];Fasting plasma total homocysteine using an immunoassay within the core clinical laroratory at Royal Perth Hospital[At baseline, 3 months and 6 months];Plasma F2-isoprostanes measured using gas chromatography-mass spectrometry[At baseline, 3 months and 6 months];24 hour urinary nitrite and nitrate excretion[At baseline, 3 months and 6 months];24 hour urinary 4-O-methylgallic acid excretion[At baseline, 3 months and 6 months]