The effect of oily fish and fish oil supplementation on markers of cardiovascular health and exercise performance

ISRCTN ISRCTN13031606
DOI https://doi.org/10.1186/ISRCTN13031606
Submission date
30/08/2024
Registration date
10/09/2024
Last edited
10/09/2024
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Circulatory System
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data
Record updated in last year

Plain English summary of protocol

Background and study aims
Evidence from observational studies, prospective cohort studies and randomized clinical intervention studies indicate that moderate doses of long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) significantly decrease the risk of fatal coronary heart disease (CHD). The exact mechanisms through which LC n-3 PUFA affects CHD are not well established but may include a decrease in fasting and postprandial triacylglycerol levels, a decrease in arrhythmias, modulation of platelet aggregation and decreased synthesis of pro-inflammatory agents and improved vascular function. In addition, there is a strong positive correlation between patients with cardiovascular disease and low mood/depression. Omega-3 highly unsaturated fatty acids (HUFAs) were recently reported in a meta-analytic review published by the British Journal of Psychiatry to have an effect size of .061 in reducing clinical symptoms of depression. The UK recommendation is that people eat at least two portions (with a portion being 140 g) of fish per week, one of which should be oily fish. Despite recommendations and sufficient availability, the majority of the UK population does not consume enough fish, particularly oily fish, and should be encouraged to increase consumption. However, it is unknown whether the benefits of eating fish come from the omega-3 fatty alone, or in combination with other macro and micronutrients within the fish. This research aims to investigate the health benefits of oily fish consumption, at a level achievable in the diet, compared to omega-3 supplementation on markers of cardiovascular health and exercise performance.

Who can participate?
Participants are required to be >40 years old, BMI >20 kg/m² and CVD scoring tool using the Framingham Risk Score

What does the study involve?
The study involves 2 testing sessions and 1 screening session where blood and urine samples are collected, and functional cognition measures and cardiovascular measures are carried out, as well as a submaximal exercise test.

Participants are assigned into one of three groups:
Group 1: placebo supplement + oily fish
Group 2: fish oil supplement + white fish
Group 3: placebo supplement + white fish
At the end of 12 weeks, participants returned to the University for a repeat session of testing.

Blood samples were used to assess:
Omega-3 index,– University of Southampton
Blood lipid profiles, number and procoagulant activity of extracellular vesicles – University of Reading

What are the possible benefits and risks of participating?
Participants will find out their blood lipid profile, and omega-3 index as well as their current fitness level.

Where is the study run from?
The School of Sport and Exercise Sciences, Liverpool John Moores University (UK)

When is the study starting and how long is it expected to run for?
July 2015 to March 2021

Who is funding the study?
British Broadcasting Corporation (UK)

Who is the main contact?
Prof Parveen Yaqoob, p.yaqoob@reading.ac.uk

Contact information

Prof Graeme Close
Public, Scientific, Principal Investigator

Liverpool John Moores University, School of Sport and Exercise Sciences, Tom Reilly Building, Byrom Street
Liverpool
L3 3AF
United Kingdom

ORCiD logoORCID ID 0000-0002-7210-9553
Phone +44 (0)151 904 6266
Email G.L.Close@ljmu.ac.uk
Prof Parveen Yaqoob
Scientific, Principal Investigator

Vice-Chancellor's Office, Whiteknights House, University of Reading
Reading
RG6 6UR
United Kingdom

ORCiD logoORCID ID 0000-0002-6716-7599
Phone +44 (0)118 378 8716 - 7113
Email p.yaqoob@reading.ac.uk

Study information

Study designRandomized double-blind placebo-controlled parallel trial
Primary study designInterventional
Secondary study designRandomised parallel trial
Study setting(s)Home, University/medical school/dental school
Study typePrevention, Quality of life
Participant information sheet Not available in web format. Please use contact details to request a participant information sheet
Scientific titleEffects of fish oil supplements vs oily fish on the number, phenotype and procoagulant activity of extracellular vesicles
Study objectivesFish oil is more effective than oily fish in reducing the number and of thrombogenic activity of extracellular vesicles
Ethics approval(s)

Approved 31/07/2015, LJMU’s Research Ethics Committee (Research and Innovation Services 1st Floor, Exchange Station, Tithebarn St, Liverpool, L2 2QP, United Kingdom; +44 (0)151 904 6467; researchethics@ljmu.ac.uk), ref: S16SPS041

Health condition(s) or problem(s) studiedPrevention of cardiovascular disease in subjects who were at above average risk of developing CVD.
InterventionThis is a randomized, double-blind, placebo-controlled, parallel trial.

Volunteers will be asked to attend 2 testing and 1 screening session at the University where blood will be taken, urine samples collected, and functional cognition measures and cardiovascular measures carried out, as well as a submaximal exercise test.

Volunteers will then be asked to eat 2 portions of fish per week and take a supplement daily for 12 weeks. Participants will be randomized into one of three groups:
Group 1: placebo supplement + oily fish
Group 2: fish oil supplement + white fish
Group 3: placebo supplement + white fish

Fish oil capsules are provided as 2.2 g/d of n-3 PUFA ethyl esters. Two oily fish meals contain 1.44 g/d of n-3 PUFA (one meal containing salmon and the other mackerel).

At the end of 12 weeks, participants will return to the University for a repeat session of testing (blood, urine and functional measures).
Intervention typeBehavioural
Primary outcome measureCirculating extracellular vesicles (EVs) numbers are measured using Nanoparticles Tracking Analysis at baseline and after the intervention
Secondary outcome measuresThe following secondary outcome measures are assessed at baseline and after the intervention:
1. Numbers of EV subpopulations including phosphatidylserine-positive EVs, platelet-derived EVs and endothelial-derived EVs are measured using a flow cytometer
2. Fatty acid compositions of circulating EVs and red blood cells (RBCs) are measured using gas chromatography
3. Thrombogenicity of circulating EVs is measured using a thrombin generation assay
4. Clot-forming and fibrinolytic capacity of circulating EVs are measured using clot formation assay and plasmin generation assay
5. Plasma lipid profile including triglycerides, total cholesterol, low-density lipoprotein and high-density lipoprotein, and plasma glucose levels are measured using Daytona Plus clinical chemistry analyzer
Overall study start date31/07/2015
Completion date09/03/2021

Eligibility

Participant type(s)Healthy volunteer
Age groupAdult
Lower age limit40 Years
Upper age limit73 Years
SexBoth
Target number of participants60
Total final enrolment42
Key inclusion criteria1. >40 years old
2. BMI >20 kg/m²
3. CVD scoring tool using the Framingham Risk Score
Key exclusion criteria1. Infection
2. Immune disorder including HIV, autoimmune disease, or fever of unknown origin
3. Unstable medical conditions requiring immediate intervention
4. Unstable or rapidly progressive neurological diseases
5. A history of haemorrhagic or ischemic stroke within the last 3 months
6. Consuming oily fish more than once per week on average
7. Allergy, hypersensitivity, or intolerance to fish, fish oils or omega-3 fats
8. Any known food allergies
9. Pregnant or breastfeeding
Date of first enrolment15/08/2016
Date of final enrolment01/12/2017

Locations

Countries of recruitment

  • England
  • United Kingdom

Study participating centre

Liverpool John Moores University
Rodney House 70
Mount Pleasant
Liverpool
L3 5UX
United Kingdom

Sponsor information

British Broadcasting Corporation (United Kingdom)
Industry

Leila Finikarides, BBC Trust Me I'm A Doctor, London Broadcasting House, 5th Floor Zone E, Portland Place, now at the Winton Centre for Evidence and Risk Communication, Cambridge
London
W1A 1AA
United Kingdom

Phone 01223 337733
Email lf426@cam.ac.uk
Website https://www.bbc.co.uk/programmes/b04j9gny and wintoncentre@maths.cam.ac.uk
ROR logo "ROR" https://ror.org/01qepzr42

Funders

Funder type

Other

British Broadcasting Corporation
Government organisation / For-profit companies (industry)
Alternative name(s)
BBC Worldwide, BBC Research and Development, BBC
Location
United Kingdom

Results and Publications

Intention to publish date30/09/2024
Individual participant data (IPD) Intention to shareYes
IPD sharing plan summaryStored in publicly available repository
Publication and dissemination planPlanned publication in a peer-reviewed journal
IPD sharing planThe datasets generated during and/or analysed during the current study will be stored in a publicly available repository in the University of Reading data repository https://doi.org/10.17864/1947.001350

Editorial Notes

10/09/2024: Trial's existence confirmed by LJMU’s Research Ethics Committee