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. Omega-3 fatty acids from foods and from supplements need to be digested in the small intestine. Emulsification is an early part of the digestive process and makes the omega-3 fatty acids more soluble. Limited emulsification may limit omega-3 fatty acid uptake into the body (bioavailability). Conversely pre-emulsification may promote omega-3 fatty acid uptake into the body. A self-microemulsifying drug delivery system (SMEDDS) promotes emulsification after oral consumption. In this study, the appearance in the blood of EPA and DHA will be compared after taking omega-3 fats in emulsified or SMEDDS forms. The aim of this study is to find out whether the self-emulsification of the supplement affects the way the fatty acids incorporate into blood fats and blood cells.
Who can participate?
Healthy men and women aged 18 to 65
What does the study involve?
Participants are randomly allocated to take one of four omega-3 supplements daily for 12 weeks (either emulsified or SMEDDS forms and at different doses). Participants make clinic visits at the start of the study and at weeks 1, 4 and 12. Blood samples are collected at each clinic visit. The amount of EPA and DHA in the blood and in blood cells are compared in order to see if there is a difference between the supplements.
What are the possible benefits and risks of participating?
There is 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?
July 2015 to August 2017
Who is funding the study?
Who is the main contact?
Prof. Philip Calder
Prof Philip Calder
Faculty of Medicine
University of Southampton
MP887 Southampton General Hospital
Incorporation of omega-3 fatty acids in healthy humans following oral dosing of dietary supplements
A self-microemulsifying drug delivery system (SMEDDS) will enhance bioavailability of the omega-3 fatty acids EPA and DHA.
South Central - Hampshire A Research Ethics Committee, 11/01/2016, ref: 15/SC/0775
Double-blind randomised parallel trial
Primary study design
Secondary study design
Randomised parallel trial
Patient information sheet
Not availble in web format, please use contact details to request a participant information sheet
Omega-3 fatty acid supplementation
Patients are manually randomised by the hospital research pharmacist to one of four groups:
1. Omega-3 ethyl esters providing 230 mg EPA + 190 mg DHA
2. SMEDDS Omega-3 ethyl esters providing 230 mg EPA + 190 mg DHA
3. Omega-3 ethyl esters providing 90 mg EPA + 300 mg DHA
4. SMEDDS Omega-3 ethyl esters providing 90 mg EPA + 300 mg DHA
Supplements (3/day) will be taken orally before breakfast. Duration of treatment will be three months. Blood samples will be collected at 0 (samples at 0, 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 and 24 hours), 1, 4 and 12 weeks.
Primary outcome measures
Concentration of EPA and DHA in red blood cells, measured by gas chromatography at baseline, 1, 4 and 12 weeks
Secondary outcome measures
Concentration of EPA and DHA in plasma and white blood cells, measured by gas chromatography at baseline, 1, 4 and 12 weeks
Overall trial start date
Overall trial end date
Participant inclusion criteria
1. Healthy males and females
2. Age 18 to 65 years
3. Body mass index 20 to 35 kg/m2
4. Not consuming fish oil or similar 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
8. Omega-3 index (EPA+DHA in red blood cells_ < 6.5 at screening
Target number of participants
Participant exclusion criteria
1. Being diabetic (type 1 or type 2)
2. Being vegetarian or vegan and unwilling to consume capsules with a beef gelatine coating
3. Use of prescribed medicine to control inflammation
5. Chronic gastrointestinal problems (e.g. IBD, IBS, celiac disease, cancer)
6. Allergic to fish
7. Allergic to soybean
8. Participation in another clinical trial (currently or in the 12 weeks prior to study entry)
9. Pregnancy or lactation
10. Blood donations during 3 months prior to or during the study period
11. Omega-3 index (EPA+DHA in red blood cells > 6.5 at screening
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
University Hospital Southampton NHS Foundation Trust
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Planned publication in peer reviewed journal (likely 2018)
IPD sharing plan
The data sharing plans for the current study are unknown and will be made available at a later date
Intention to publish date
Participant level data
To be made available at a later date
Results - basic reporting