Plain English Summary
Background and study aims
The most prevalent disease in adults is hypertension (high blood pressure). The guidelines propose to start treatment in primary care with healthy lifestyle advice and medication if blood pressure is not normalized or the patient has a high cardiovascular (heart disease) risk. The olive leaf contains oleuropein, which has traditionally been used to lower blood pressure. The aim of this study is to measure blood pressure in adults with hypertension treated with olive leaf extract.
Who can participate?
Patients aged 25-65 with hypertension
What does the study involve?
Participants are randomly allocated to take either two placebo (dummy) tablets once daily or two tablets of olive leaf extract once daily for 30 days, followed by a 15-day break, after which they take the other tablets for 30 days. Blood pressure is measured before and after each treatment period. A blood sample is taken before the first treatment period, during the 15-day break, and after the second treatment period. Each participant is asked on a weekly basis about the palatability of the tablets.
What are the possible benefits and risks of participating?
No direct benefits are expected for the participants. It is possible that the blood pressure measurement provides useful information for the subsequent treatment of these patients. Some cases of mild digestive intolerance and bitter taste have been reported with olive leaf extract. There is no serious risk to health.
Where is the study run from?
CAP Ernest lluch (Spain)
When is the study starting and how long is it expected to run for?
February 2017 to November 2018
Who is funding the study?
Who is the main contact?
1. Prof. Gabriel Coll de Tuero
2. Ms Rufina Espín Sanchez
Prof Gabriel Coll de Tuero
Ms Rufina Espín Sanchez
Mild hypertension treated with olive leaf extract clinical trial
1. The treatment of mild essential hypertension (HT) with a brief advice on healthy lifestyle and leaf olive extract at doses recommended by the European Medicines Agency (EMA) will reduce the systolic and diastolic blood pressure significantly.
2. The treatment of the Mild HT with a brief advice on lifestyle modifications and olive leaf extract will allow a better control of blood pressure in a higher percentage than the group that receives only brief advice about lifestyle modifications.
Clinical Ethics Committee of the IDIAP Jordi Gol and Gurina, 27/09/2017, Protocol P17/038
Randomized cross over double-blind trial
Primary study design
Secondary study design
Randomised cross over trial
Patient information sheet
Not available in web format, please use contact details to request a participant information sheet
From the population of Figueres city a sample population of 48 individuals will be extracted, by simple random sampling, these will be randomized into two groups A and B:
A. OLE, marketed under the name Olive Oil extract 20% (oleuropein Sura Vitasan 60 capsules, containing 1000 mg extract and 20% oraloleic)
B. Placebo with the same appearance
Each of the participants will receive 2 placebo tablets each day (once daily) or 2 tablets of active principle each day (once daily) of olive leaf extract with 20% oleuropein (1000 mg). Each participant will take the active treatment or placebo for 30 days, followed by a 15-day washout period, after which they will take placebo or active treatment. Each participant will be randomized to start the first period with placebo or active treatment.
A blood sample analysis will be done before the 1st exposure, during the washout period (intermediate), and after the 2nd exposure has finished. Each participant will be asked on a weekly basis for their palatability.
Primary outcome measure
Ambulatory blood pressure (in mmHg) measured at the beginning and end of each treatment period (placebo or active treatment)
Secondary outcome measures
Hypertension control (BP < 140/90 mmHg; in percentage) measured at the beginning and end of each treatment period (placebo or active treatment)
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Men and women aged 25-65
2. Diagnosed with essential hypertension grade 1
3. Without allergy to the components of the leaf extract of the olive or the capsule
4. Low CV risk
5. Who don't take hypertension treatment a month before inclusion
6. Do not have a target organ lesion and/or chronic illnesses (kidney, respiratory, cardiac, liver, haematological, infectious, etc) according to the European Guide for the management of the HTA ESH ESC 2013
7. Informed consent
Target number of participants
Total final enrolment
Participant exclusion criteria
1. People with HTA grade 2 and 3
2. Grade 1 with a moderate CV risk, or high or very high according to the ESH-ESC 2013 Guidelines
3. With LOD or with subclinical vascular disease
4. With cognitive or idiomatic difficulty in fulfilling the instructions
5. Having chronic illnesses
6. Taking treatments that interfere or contraindicate the administration of the components of the olive leaf
7. Lactose intolerance
8. Pregnancy or breastfeeding
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
CAP Ernest lluch
Institut Universitari d'Investigació en Atenció primària Jordi Gol i Gorina (IdIAP)
Gran Via de les Corts Catalanes,591 Atic
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
The results of the trial will be published in international journals in the second quarter of 2019. The results will also be presented at national (Spanish Society of hypertension) and International (European Society of Hypertension) congresses.
IPD sharing statement
The datasets generated during and/or analysed during the current study will be available upon request from Rufina Espín (email@example.com) from January 2019. The data will always be provided anonymized for reviews or meta-analysis whenever the principal investigators consider it appropriate. There are no legal restrictions to share this data as long as they are properly anonymized.
Intention to publish date
Participant level data
Available on request
Basic results (scientific)