Omega-3 Fatty Acids (EPA/DHA)
Also known as: Fish oil · EPA · DHA · Epanova · Omega-3 free fatty acids
Essential fatty acids that feed your body’s inflammation-resolving pathways. Promising early Crohn’s results; larger trials were mixed.
Mixed clinical results. A New England Journal of Medicine trial of enteric-coated fish oil reported a large drop in relapse; two later large trials using a different formulation did not find a relapse benefit. Formulation may be key.
Affiliate disclosure: We may earn a commission on recommended products, at no extra cost to you. Learn more
How it works
EPA and DHA are incorporated into cell membranes, where they shift the body’s production of signalling molecules away from pro-inflammatory arachidonic-acid derivatives toward gentler ones. Even more importantly, they are the raw material for resolvins and protectins — specialised molecules that actively switch inflammation off once its job is done. Crohn’s-related fat malabsorption can leave people low in these essential fats to begin with, making replenishment a foundational step.
Traditional use
Cod liver oil was a daily folk tonic across Northern Europe for centuries. Interest in omega-3s for inflammation grew from observations of traditional Inuit and Japanese coastal diets rich in oily fish.
Highlights
- A New England Journal of Medicine trial found 1-year relapse of 28% with enteric-coated fish oil versus 69% on placebo.
- Omega-3s are precursors to resolvins — the body’s own “off switch” for inflammation.
- Two later large trials using a free-fatty-acid formulation did not show a relapse difference, suggesting the form used matters.
- Many people with Crohn’s are low in essential fatty acids due to fat malabsorption.
- Broad benefits for heart, brain and joint health make it a foundational supplement for many.
What the research shows
Every study below links to its original publication so you can read it yourself. Many natural compounds have only been studied in small trials. That isn’t a verdict on them; it reflects how little funding exists for compounds that can’t be patented.
| Study | Design & population | Outcome |
|---|---|---|
| Belluzzi 1996 Positive result | Randomised, double-blind, placebo-controlled maintenance trial 78 patients · Crohn’s disease in remission at high risk of relapse | Relapse at 1 year in 28% on enteric-coated fish oil versus 69% on placebo. |
| Feagan 2008 No significant difference | Two randomised, double-blind, placebo-controlled trials (EPIC-1 and EPIC-2) 738 patients across both trials · Crohn’s disease in remission | No reduction in relapse. EPIC-1: 31.6% vs 35.7%. EPIC-2: 47.8% vs 48.8%. |
| Lev-Tzion 2014 No significant difference | Cochrane systematic review and meta-analysis 1,039 patients across 6 studies · Crohn’s disease in remission | Omega-3 fatty acids are probably ineffective for maintenance of remission in Crohn’s disease. |
Randomised, double-blind, placebo-controlled maintenance trial · 78 patients · Crohn’s disease in remission at high risk of relapse
Relapse at 1 year in 28% on enteric-coated fish oil versus 69% on placebo.
Two randomised, double-blind, placebo-controlled trials (EPIC-1 and EPIC-2) · 738 patients across both trials · Crohn’s disease in remission
No reduction in relapse. EPIC-1: 31.6% vs 35.7%. EPIC-2: 47.8% vs 48.8%.
Cochrane systematic review and meta-analysis · 1,039 patients across 6 studies · Crohn’s disease in remission
Omega-3 fatty acids are probably ineffective for maintenance of remission in Crohn’s disease.
Using it alongside conventional care
Omega-3s are one of the most widely used supplements among people living with Crohn’s, whether they are on Humira, Entyvio, Azathioprine or managing without medication. The research story is a useful one: an enteric-coated preparation showed a striking benefit, while a different free-fatty-acid formulation did not — a reminder that form and quality matter. Most people use fish oil as a foundational, everyday support rather than as a stand-alone approach. It has a mild blood-thinning effect at higher doses, so let your care team know before any procedure.
Medications mentioned
Humira (adalimumab)
Anti-TNF biologic
Neutralises tumour necrosis factor alpha (TNF-α), a master cytokine driving intestinal inflammation.
Entyvio (vedolizumab)
Gut-selective integrin blocker
Blocks α4β7 integrin, preventing lymphocyte trafficking into gut tissue.
Azathioprine (azathioprine / 6-mercaptopurine)
Thiopurine immunomodulator
Purine antimetabolite that depletes activated lymphocytes.
Never stop or change a prescribed medication without your gastroenterologist. Many people use natural support alongside conventional care, and your care team can help you do that safely.
Recommended sourcing
Where to buyWhat to look for in Omega-3 Fatty Acids
- Enteric-coated capsules — the form used in the positive NEJM trial
- Triglyceride (TG or rTG) form for better absorption
- IFOS or third-party certification for purity and freshness
- Clearly stated EPA + DHA per serving (not just “fish oil” mg)
The positive trial used 2.7 g/day of combined EPA and DHA. Fresh oil should not smell strongly fishy.
Shop trusted retailers
Paid links: we may earn a commission when you buy through these links, at no extra cost to you. These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.
Amounts used in research
Belluzzi used 2.7 g/day of enteric-coated EPA/DHA. EPIC used 4 g/day of omega-3 free fatty acids. Trial durations were 12 months.
Good to know
- Very well tolerated; fishy aftertaste, belching and loose stools are the usual complaints.
- Mild antiplatelet effect at gram-level doses — flag it before surgery or alongside anticoagulants.
- Enteric coating substantially improves GI tolerability and may matter mechanistically.
- Choose preparations tested for heavy metals and oxidation; rancid fish oil is pro-oxidant.
Community experiences
Reported benefit
Typical dose
Time to notice
Common pairings
Real-world data for Omega-3 Fatty Acids is coming. When our Community Symptom Tracker launches, this section will show anonymised, aggregated experiences from people with Crohn’s who have tried Omega-3 Fatty Acids: how many noticed a difference, what they took, and what they paired it with.
Community data will always be labelled as self-reported, and it won’t replace the published research above.
Coming soon
Tried Omega-3 Fatty Acids? Your experience matters.
Our Community Symptom Tracker will let you log what you take and how you feel — and see what’s working for people like you. Alongside it, our wellness store will offer curated, third-party-tested protocols.
Sources
-
Effect of an enteric-coated fish-oil preparation on relapses in Crohn’s disease
Belluzzi A, Brignola C, Campieri M, Pera A, Boschi S, Miglioli M. · New England Journal of Medicine · 1996 · PMID 8637514
-
Feagan BG, Sandborn WJ, Mittmann U, et al. · JAMA · 2008
-
Omega 3 fatty acids (fish oil) for maintenance of remission in Crohn’s disease
Lev-Tzion R, Griffiths AM, Leder O, Turner D. · Cochrane Database of Systematic Reviews · 2014
Phase 2 — in development
Where traditional research stops, our community begins
Natural compounds can’t be patented, so they rarely get the multi-million-dollar trials that drugs receive. That leaves people with Crohn’s without answers to the questions that matter most: what actually helps, at what dose, and for whom? Our Community Symptom Tracker will crowdsource those answers from real people living with Crohn’s, and our upcoming wellness store will make it easy to find quality, third-party-tested products.
- Log your symptoms, supplements and doses in a private daily tracker
- See what’s working for people with the same disease location and medications
- Contribute to the largest real-world dataset on natural Crohn’s support
- Shop curated, third-party-tested protocols from our upcoming store
Be one of the first to join
Early access is opening soon. Bookmark this page and check back — we’ll announce sign-ups here first.