Effect of fish and omega 3 supplements on the heart health of young adults
| ISRCTN | ISRCTN16260195 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN16260195 |
| Sponsor | University of Ulster |
| Funder | Northern Ireland Chest Heart and Stroke |
- Submission date
- 01/12/2025
- Registration date
- 03/12/2025
- Last edited
- 03/12/2025
- Recruitment status
- Not yet recruiting
- Overall study status
- Ongoing
- Condition category
- Circulatory System
Plain English summary of protocol
Background and study aims
Heart disease is one of the leading causes of death, but research shows that about 75% of cases could be prevented. Omega-3 fats, found in fish, are known to help reduce inflammation and lower the risk of heart disease. A useful measure of omega-3 levels in the body is called the omega-3 index (O3I). People with an O3I above 8% have the lowest risk of heart disease, but most people have an O3I of only 4–5%. Eating fish or taking omega-3 supplements can help increase this level, but it’s not clear if current advice is enough to reach the target. This study will look at whether eating fish or taking omega-3 supplements can improve omega-3 levels and blood vessel health in young adults.
Who can participate?
Healthy men and women aged 18–30 who eat very little fish (less than two portions per month) and do not take fish oil or protein supplements can take part. Participants must have an omega-3 index below 6% and not be allergic to seafood.
What does the study involve?
Participants will be randomly placed into one of three groups:
-A group that eats fish meals
-A group that takes omega-3 supplements
-A group that takes placebo supplements
Those in the fish group will visit Ulster University twice a week for 12 weeks to receive two fish-based lunches (about 280g of fish per week). Blood samples will be taken to measure omega-3 levels and assess vascular health.
What are the possible benefits and risks of participating?
You may benefit from improved omega-3 levels and better heart health in the long term. Risks are minimal but include mild discomfort from blood sampling and, for those eating fish, the usual risks linked to seafood (such as allergies, which will be screened for).
Where is the study run from?
The study is run at the Human Intervention Studies Unit at Ulster University, Coleraine (UK)
When is the study starting and how long is it expected to run for?
The study will run for 12 weeks once participants are enrolled.
Who is funding the study?
The study is funded by Northern Ireland Chest Heart and Stroke’s Research Grant Programme.
Who is the main contact?
Professor Emeir McSorley
em.mcsorley@ulster.ac.uk
Contact information
Principal investigator, Scientific, Public
Ulster University, Cromore Road
Coleraine
BT521SA
United Kingdom
 ORCID ID |
0000-0003-1861-3991 |
|---|---|
| Phone | +44 2870123543 |
| Em.mcsorley@ulster.ac.uk |
Study information
| Primary study design | Interventional | |
|---|---|---|
| Allocation | Randomized controlled trial | |
| Masking | Blinded (masking used) | |
| Control | Placebo | |
| Assignment | Parallel | |
| Purpose | Basic science, Efficacy | |
| Scientific title | The effects of fish consumption and omega 3 supplementation in reducing risk of cardiovascular disease in young adults (CardioFish) | |
| Study acronym | CardioFish | |
| Study objectives | The primary aim of this study is to determine the effect of following current guidance for fish consumption and omega 3 supplementation on the O3I of young adults aged between 18-30 years. Secondary aims will explore the effects of fish or omega 3 supplements on the health of young adults including vascular health, markers of vascular inflammation and lipid profiles. | |
| Ethics approval(s) |
Approved 02/09/2025, Ulster University Research Governance (Ulster University, Belfast Campus. Room BD-04-005 2-24 York Street, Belfast, BT15 1AP, United Kingdom; +442895365028; researchgovernance@ulster.ac.uk), ref: REC/25/0033 | |
| Health condition(s) or problem(s) studied | Cardiovascular disease prevention | |
| Intervention | Arm 1 – 2 portions of fish (280g) per week Arm 2 – Daily 1g omega 3 supplement – 400mg EPA+ 200mg DHA per day. Arm 3 – Daily 1g placebo supplement (corn oil) All three study arms will receive a 12-week intervention. Outcome assessments will be conducted at baseline and at the end of the 12-week intervention period; no additional follow-up beyond 12 weeks is planned. Randomisation will be performed by an independent researcher who is not involved in participant recruitment or assessment. Allocation will be conducted using MINIM software to ensure balanced distribution across study arms. | |
| Intervention type | Mixed | |
| Primary outcome measure(s) |
| |
| Key secondary outcome measure(s) |
| |
| Completion date | 21/12/2026 |
Eligibility
| Participant type(s) | |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Upper age limit | 30 Years |
| Sex | All |
| Target sample size at registration | 117 |
| Key inclusion criteria | 1. Omega-3 index < 6% 2. Healthy males or females 3. Aged 18–30 years old 4. Low consumers of fish (< 2 portions/month) 5. Willing to consume 2 portions (280 grams) of fish per week 6. Not consuming fish oil supplements 7. Not consuming protein supplements 8. Within a BMI of 18–30 kg/m² 9. Not allergic to seafood |
| Key exclusion criteria | 1. Omega-3 index > 6% 2. Regularly consume fish 3. Are allergic to seafood 4. Are taking fish oil supplements (e.g., fish oil, cod oil, krill oil, GLA, or evening primrose) or protein supplements (e.g., whey protein) 5. Are pregnant or lactating 6. Have existing health conditions such as Diabetes Mellitus or known hypertension 7. Have dietary restrictions resulting in the exclusion of fish (e.g., vegan) |
| Date of first enrolment | 26/01/2026 |
| Date of final enrolment | 21/09/2026 |
Locations
Countries of recruitment
- United Kingdom
- Northern Ireland
Study participating centre
Coleraine
BT521SA
Northern Ireland
Results and Publications
| Individual participant data (IPD) Intention to share | No |
|---|---|
| IPD sharing plan summary | Not expected to be made available |
| IPD sharing plan |
Editorial Notes
01/12/2025: Trial's existence confirmed by Ulster University.
