Condition category
Not Applicable
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Plain English Summary

Background and study aims
We are carrying out a study to compare the appearance in the blood of two omega-3 fats, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), as a result of the taking supplements providing omega-3 fats in different chemical forms. Our goal is to find out whether the chemical form of the supplement affects the incorporation of the fatty acids into blood fats and blood cells. If the different chemical forms are incorporated to different extents or at different rates this may influence their ability to affect health. Thus this information will be important to consumers, to supplement manufacturers, and to government and other regulatory authorities.

Who can participate?
100 healthy men and women aged 18 to 45 years.

What does the study involve?
Participants will be randomly allocated to take one of five supplements daily for 12 weeks (either omega-3 fats in one of four chemical forms or a placebo [dummy] supplement). Participants will make clinic visits at the start of the study and at weeks 1, 2, 4, 8 and 12. Blood will be collected at each clinic visit. At the end of the study, we will compare the amount 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?
Study recruitment started in January 2012 and participants were enrolled for 12 weeks.

Who is funding the study?
Vifor Pharma (Switzerland).

Who is the main contact?
Professor Philip Calder

Trial website

Contact information



Primary contact

Prof Philip Calder


Contact details

Southampton General Hospital
Faculty of Medicine
Tremona Road
SO16 6YD
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Incorporation of omega-3 fatty acids from different chemical forms into blood lipid pools in healthy humans


Study hypothesis

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.

Ethics approval

Southampton and South west Hampshire Research Ethics Committee, 02/06/2011, ref: 11/SC/0049

Study design

Randomised placebo-controlled double-blind parallel study

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Healthy subjects


Participants were allocated to one of the following groups:
1. Placebo
2. Omega-3 ethyl esters
3. Omega-3 free fatty acids
4. Omega-3 triglycerides (standard formulation)
5. Omega-3 triglycerides (interesterified formulation)

All forms of supplement provide 1.1 g EPA plus 0.4 g DHA daily. Supplements will be taken orally. The duration of treatment will be 3 months. Blood samples will be taken during supplementation at 0, 1, 2, 4, 8 and 12 weeks.

Intervention type



Drug names

Primary outcome measure

Change in EPA content of plasma phospholipids from study entry to week 12

Secondary outcome measures

1. Change in EPA content of each of the other plasma lipid pools and of mononuclear cells and red blood cells from study entry to week 12
2. Change in DHA content of each of the plasma lipid pools and of mononuclear cells and red blood cells from study entry to week 12
3. Change over time in blood concentrations of inflammatory markers

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Healthy
2. Aged 18 to 45 years
3. Body mass index 20 to 32 kg/m2
4. Not consuming fish oil or other oil supplements
5. Not eating more than one oily fish meal per week
6. Willing to adhere to the study protocol
7. Being able to provide written informed consent

Participant type

Healthy volunteer

Age group




Target number of participants


Participant exclusion criteria

1. Aged < 18 or > 45 years
2. Body mass index < 20 or > 32 kg/m2
3. Being diabetic (type 1 or type 2)
4. Use of prescribed medicine to control inflammation
5. Chronic gastrointestinal problems (e.g. IBD, IBS, celiac disease, cancer)
6. Allergic to fish
7. Participation in another clinical trial
8. Use of fish oil or other oil supplements

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Southampton General Hospital
SO16 6YD
United Kingdom

Sponsor information


Southampton University Hospitals NHS Trust (UK)

Sponsor details

Research & Development Offices
Southampton General Hospital
Tremona Road
SO16 6YD
United Kingdom

Sponsor type

Hospital/treatment centre



Funder type


Funder name

Vifor Pharma (Switzerland)

Alternative name(s)

Funding Body Type

Funding Body Subtype


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

Basic results (scientific)

Publication list

2016 results in:

Publication citations

Additional files

Editorial Notes

27/04/2018: Publication reference corrected. 14/06/2017: Publication reference added.