Plain English Summary
Background and study aims
Omega-3 fatty acids are essential in the diet, as the body is unable to make them itself (essential fatty acids). Although they can be found in plant sources, the most important omega-3 fatty acids are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are only found in certain types of fish. There are a wide variety of different omega-3 supplements of the market, which provide EPA and DHA in different forms. In this study, the appearance in the blood of EPA and DHA after taking omega-3 fats in different chemical forms will be compared. The aim of this study is to find out whether the chemical form of the supplement affects the way the fatty acids incorporate into blood fats and blood cells.
Who can participate?
Healthy men aged 18 to 45 years.
What does the study involve?
Participants are randomly allocated to five groups, who consume five different omega-3 fat supplements with a standard high fat meal in a random order. The meals are eaten on five separate study visits spaced two weeks apart. At each clinic visit, a blood sample is taken and then the participants are asked to eat the meal (and omega-3). After this, further blood samples are taken 30 minutes, one, one and a half, two, two and a half, three, four, five and six hours after finishing the meal in order to measure levels of EPA and DHA in the blood and in blood cells in order to see if there is a difference between the supplements.
What are the possible benefits and risks of participating?
There will be no immediate direct benefit to those taking part. There is a very small chance of infection and a chance of bleeding and bruising at the site of insertion of the needle for collecting the blood sample.
Where is the study run from?
University of Southampton (UK)
When is the study starting and how long is it expected to run for?
October 2009 to September 2010
Who is funding the study?
Vifor Pharma (Switzerland)
Who is the main contact?
Professor Philip Calder
Bioavailability and disposition of omega-3 fatty acids from different chemical forms
The appearance of Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA) in plasma lipids and blood cells will differ according to chemical formulation of the parent oil.
Isle of Wight, Portsmouth and South East Hampshire Research Ethics Committee, 04/02/2010, ref: 09/H0501/98
Randomised blinded single-centre cross-over trial
Primary study design
Secondary study design
Randomised cross over trial
Patient information sheet
Not available in web format, please use the contact details to request a patient information sheet
Participants will be allocated to one of the following groups:
1. Omega-3 ethyl esters
2. Omega-3 free fatty acids
3. Omega-3 triglycerides (standard formulation)
4. Omega-3 triglycerides (interesterified formulation)
5. Omega-3 triglycerides (standard formulation enterically coated)
All forms of supplement provide 1.1 g EPA plus 0.4 g DHA daily. Supplements will be taken orally immediately following consumption of a standard high fat meal. Blood samples will be immediately before the meal and at 0.5, 1, 1.5, 2, 2.5, 3, 4, 5 and 6 h after consuming the meal.
All subjects will consume all five types of supplement in random order and separated by at least two weeks.
Primary outcome measure
Change in EPA and DHA contents of plasma phospholipids is measured using blood testing at baseline (immediately before the meal) and 0.5, 1, 1.5, 2, 2.5, 3, 4, 5 and 6 hours after consuming the meal
Secondary outcome measures
1. Change in EPA content of plasma triglycerides, cholesteryl esters and non-esterified fatty acids, and erythrocytes and mononuclear cells over 6 hours
2. Change in DHA content of plasma triglycerides, cholesteryl esters and non-esterified fatty acids, and erythrocytes and mononuclear cells over 6 hours
3. Change in blood concentrations of inflammatory markers over 6 hours
All secondary outcomes are measured using blood testing at baseline (immediately before the meal) and 0.5, 1, 1.5, 2, 2.5, 3, 4, 5 and 6 hours after consuming the meal.
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
2. Aged 18 to 45 years
3. In general good health
4. Body mass index between 20 and 32 kg/m2
5. Not consuming fish oil or other oil supplements
6. Not eating more than one oily fish meal per week
7. Willing to adhere to the study protocol
8. Being able to provide written informed consent
Target number of participants
Participant exclusion criteria
2. Aged under 18 or over 45 years
3. Body mass index less than 20 or more than 32 kg/m2
4. Being diabetic (type 1 or type 2)
5. Use of prescribed medicine to control inflammation
6. Chronic gastrointestinal problems (e.g. IBD, IBS, celiac disease, cancer)
7. Participation in another clinical trial
8. Use of fish oil or other oil supplements
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
University of Southampton
Faculty of Medicine
Vifor Pharma Ltd., Vifor Pharma Management Ltd., Vifor Pharma Management AG, Vifor Pharma Management SA
Funding Body Type
private sector organisation
Funding Body Subtype
For-profit companies (industry)
Results and Publications
Publication and dissemination plan
Planned publication of a results paper in a peer reviewed journal.
Intention to publish date
Participant level data
To be made available at a later date
Basic results (scientific)
2016 results in: https://www.ncbi.nlm.nih.gov/pubmed/27424661