Condition category
Nutritional, Metabolic, Endocrine
Date applied
02/06/2014
Date assigned
09/07/2014
Last edited
19/02/2015
Prospective/Retrospective
Retrospectively registered
Overall trial status
Completed
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
Virgin olive oil is widely used in Mediterranean food and has been associated with health benefits such as protection against heart disease. For many years, the beneficial properties of olive oil were attributed to a type of fat named oleic acid. Besides containing high quantities of oleic acid, some olive oils contain small molecules called phenolic compounds, which are known as natural antioxidants. Little is known about the fate of these compounds in the body once they are consumed, or where they do to influence health. This study aims to find out the contribution of phenolic compounds present in virgin olive oil to the prevention of diseases and promotion of health using new biomarker techniques (a biomarker is a small molecule acting as a ‘reporter’ for health and disease).

Who can participate?
Healthy adults, aged 18-75, who are not allergic to olive products.

What does the study involve?
Your body weight, height, waist circumference and blood pressure will be recorded and you will fill in a questionnaire to help us establish your intake of foods rich in phenolic compounds. During the 6-week study period, you will be randomly allocated to take a daily dose of olive oil (20 ml) with either a high or low polyphenolic content, to be consumed uncooked. At the beginning, middle and end of the study, participants will be asked to keep a record of the food eaten the day before the visit, to collect a ‘spot’ urine sample in a small tube (second urine of the day) and to provide a blood sample. We will measure, in urine and blood, the levels of small molecules (biomarkers) that are related to heart and kidney health, as well as the way food is digested, transformed in the body and excreted.

What are the possible benefits and risks of participating?
There are no benefits or risks associated with taking part in the trial.

Where is the study run from?
Not provided at time of registration.

When is the study starting and how long is it expected to run for?
The study started in July 2012 and ran for 6 weeks.

Who is funding the study?
University of Lisbon (Portugal).

Who is the main contact?
Dr William Mullen
william.mullen@glasgow.ac.uk

Trial website

Contact information

Type

Scientific

Primary contact

Dr William Mullen

ORCID ID

Contact details

Institute of Cardiovascular and Medical Sciences
Joseph Black Building
University of Glasgow
Glasgow
G12 8QQ
United Kingdom

Additional identifiers

EudraCT number

ClinicalTrials.gov number

Protocol/serial number

2012071

Study information

Scientific title

Bioavailability of virgin olive oil bioactive compounds and impact of a 6-week supplementation on biomarkers of coronary artery disease, chronic kidney disease or diabetes

Acronym

Study hypothesis

Can a 6-week supplemetation of olive oil with either a high or low polyphenolic content alter proteomic biomarkers of coronary artery disease, chronic kidney disease or diabetes?

Ethics approval

Ethics committee of the University of Glasgow, College of Medical, Veterinary and Life Sciences, 31/08/2012, ref. 2012071.

Study design

Double-blind parallel supplementation study with low and high polyphenolic olive oil

Primary study design

Interventional

Secondary study design

Randomised controlled trial

Trial setting

Other

Trial type

Prevention

Patient information sheet

Patient information is available as a leaflet that can be obtained by contacting Dr Emilie Combet by telephone on 0141 201 0768 or via e-mail at emilie.combetaspray@glasgow.ac.uk, or Dr Bill Mullen on 0141 330 6210 (bill.mullen@glasgow.ac.uk). A third party who will be able to advise on the general research process is Professor Mike Lean (mike.lean@glasgow.ac.uk).

Condition

Risk of coronary artery disease, chronic kidney disease and diabetes

Intervention

66 healthy volunteers will be randomly allocated into one of two groups and asked to consume 20 ml of olive oil per day for 6 weeks.

Group 1 will be given olive oil with a high polyphenolic content.
Group 2 will be given olive oil with a low polyphenolic content.

Blood and urine samples will be collected the day before the study starts and also after 3 weeks and at the end of the study. Blood pressure and weight will be recorded at these visits too.

Intervention type

Other

Phase

Not Applicable

Drug names

Primary outcome measures

Proteomic urinary biomarkers of coronary artery disease, chronic kidney disease and diabetes. These will be measured after 3 weeks, the mid point and after 6 weeks, the end of the study.

Secondary outcome measures

Plasma-based biomarkers of heart disease and blood pressure. These will be measured after 3 weeks, the mid point and after 6 weeks, the end of the study.

Overall trial start date

01/07/2012

Overall trial end date

31/08/2012

Reason abandoned

Eligibility

Participant inclusion criteria

Healthy adults, aged 18-75 years

Participant type

Patient

Age group

Adult

Gender

Both

Target number of participants

66

Participant exclusion criteria

1. Those allergic to olive products
2. Currently taking medication (other than the contraceptive pill)
3. Have taken antibiotics in the last 3 months
4. Have received or are receiving treatments for any chronic gut disease
5. Is pregnant, trying to conceive, or lactating

Recruitment start date

01/07/2012

Recruitment end date

31/08/2012

Locations

Countries of recruitment

United Kingdom

Trial participating centre

Institute of Cardiovascular and Medical Sciences
Glasgow
G12 8QQ
United Kingdom

Sponsor information

Organisation

University of Glasgow (UK)

Sponsor details

c/o Dr WIlliam Mullen
Institute of Cardiovascular and Medical Sciences
Joseph Black Building
Glasgow
G12 8QQ
United Kingdom

Sponsor type

University/education

Website

Funders

Funder type

University/education

Funder name

University of Lisbon, in collaboration with the Sovena company (Portugal)

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

2015 results in: http://www.ncbi.nlm.nih.gov/pubmed/25527749

Publication citations

  1. Results

    Silva S, Bronze MR, Figueira ME, Siwy J, Mischak H, Combet E, Mullen W, Impact of a 6-wk olive oil supplementation in healthy adults on urinary proteomic biomarkers of coronary artery disease, chronic kidney disease, and diabetes (types 1 and 2): a randomized, parallel, controlled, double-blind study, Am J Clin Nutr, 2015, 101, 1, 44-54, doi: 10.3945/ajcn.114.094219.

Additional files

Editorial Notes