Olive Leaf Extract as Part of a Healthy Lifestyle in the Reduction of Blood Pressure

Study Overview
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Brief Summary
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Hypertension affects about 30% of the United Kingdom population and is causally implicated in the aetiology of renal disease, cardiovascular disease and stroke. Ageing, obesity, a poor diet and low levels of physical activity are all risk factors. Studies have shown that adherence to a Mediterranean diet is protective against hypertension and its associated morbidities; olive oil is believed to be a key beneficially bioactive component of that diet. As a source of lipids olive oil is an unremarkable blend of monounsaturated, polyunsaturated and saturated fatty acids; it is however rich in phenolic compounds, principally oleuropein and hydroxytyrosol, which may be of benefit to health. A recent randomised intervention trial in predominantly hypertensive volunteers showed that adherence to a Mediterranean diet supplemented with extra virgin olive oil, reduced blood pressure and other measures of cardiovascular disease risk. Olive phenolics can be extracted cheaply from the waste products of olive oil manufacture, such as the plant leaf and these are used as dietary supplements. In intervention studies in hypertensive or borderline hypertensive patients, olive leaf extract consumption has been shown to reduce blood pressure. Another intervention with established efficacy for improving blood pressure is to increase physical activity. The 'Start Active, Stay Active', Chief Medical Officers report on physical activity recommends that adults achieve 150 minutes of moderate intensity physical activity per week, while data in that report suggest that fewer than 40% of adult men and 30% of adult women achieve these targets. Adherence to the physical activity guidelines may in fact be much worse in sub-sections of the population at higher risk of hypertension. From a public health perspective, holistic guidelines for the prevention of hypertension, or its early diagnosis and management, based around a healthy diet and lifestyle are preferable to pharmaceutical intervention. Lifestyle interventions are economically favourable and they come with fewer side effects and perhaps wider health benefits than antihypertensive drugs. The aim of the study is to evidence the synergistic benefits of consuming plant (and specifically olive) phenolics alongside achieving the recommended guidelines for physical activity in individuals with elevated blood pressure.

Official Title
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Olive Leaf Extract as Part of a Healthy Lifestyle in the Reduction of Blood Pressure

Conditions
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Pre Hypertension

Intervention / Treatment
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* Dietary Supplement: Olive leaf extract
* Dietary Supplement: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Men and women 25-70y BMI >25kg/m2 Not having suffered a myocardial infarction/stroke in the past 12 months Not diabetic (diagnosed or fasting glucose > 7 mmol/l) or suffer from other endocrine disorders Not suffering from renal or bowel disease or have a history of cholestatic liver or pancreatitis Not on drug treatment for hyperlipidaemia, hypertension, inflammation or hypercoagulation No history of alcohol misuse Not planning or on a weight reducing regime Not taking any fish oil, fatty acid or vitamin and mineral supplements Non smokers Exclusion Criteria: Use of antibiotics within the previous 6 months History of alcohol or drug abuse Intake of any experimental drug within 4 weeks of the start of the study Excessive alcohol consumption (more than 21 units/wk male, 15 units/wk female) Females who are breast-feeding, may be pregnant, or of child-bearing potential and not using effective contraceptive precautions Have had recently (in the last 5 years) major surgery, which might limit participation in, or completion of, the study. On drug treatment for high blood fats, high blood pressure and blood clotting. Physical or mental diseases that are likely to limit participation or completion of the study

Ages Eligible for Study
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Minimum Age: 25 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Placebo control<br>2 capsules of 350 mg maltodextrin to be consumed daily for 12 weeks | Dietary Supplement: Placebo<br>* 700 mg Maltodextrin per day<br>* Other names: Maltodextrin;|
| Active Comparator: Olive leaf extract<br>2 capsules of 350 mg olive leaf extract equivalent 132 mg of oleuropein in olive leaf extract to be consumed daily for 12 weeks | Dietary Supplement: Olive leaf extract<br>* 132 mg of oleuropein per day suspended in olive leaf extract 700 mg<br>|
| Placebo Comparator: Physical activity<br>2 capsules of 350 mg maltodextrin to be consumed daily combined with gradually increase physical activity levels over 12 weeks | Dietary Supplement: Placebo<br>* 700 mg Maltodextrin per day<br>* Other names: Maltodextrin;|
| Active Comparator: Physical activity and olive leaf extract<br>2 capsules of 350 mg olive leaf extract equivalent 132 mg of oleuropein in olive leaf extract to be consumed daily combined with gradually increase physical activity levels over 12 weeks | Dietary Supplement: Olive leaf extract<br>* 132 mg of oleuropein per day suspended in olive leaf extract 700 mg<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Blood pressure measured via 24 hour ambulatory blood pressure monitors | measured using the ScanMed Oscillometric Ambulatory blood pressure deviceVolunteers will be asked to wear the device which will be programmed to record BP measurements every 30 minutes during the day (7am-10pm) and every hour by night (10pm-7am) | 12 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Average plasma glucose concentration | a measure of chronic blood sugar control) by measuring of glycated haemoglobin (HbA1c) | 12 weeks | 
| Vascular function assessed by pulse wave velocity (PWV) |  | 12 weeks | 
| Plasma biomarkers of endothelial function including nitric oxide, vascular cell adhesion molecule (VCAM), Inter-Cellular Adhesion Molecule (ICAM), E-selectin, von Willebrand factor |  | 12 weeks | 
| Fasting lipid profile including measures of total, low density lipoprotein (LDL) and high density lipoprotein (HDL) cholesterol, triglycerides and non-esterified fatty acids |  | 12 weeks | 
| Indices of insulin resistance derived from fasted measures of glucose, insulin and non-esterified fatty acids (revised QUICKI statistical analysis) |  | 12 weeks | 
| Haemostatic factors including Plasminogen activator inhibitor-1 (PAI-1) |  | 12 weeks | 
| Inflammatory biomarkers including the acute phase proteins, C-reactive protein (CRP), tumour necrosis factor alpha (TNFα), Interleukin-6 (IL6) |  | 12 weeks |