Fish oil (omega-3)

Evidence by condition

Each grade reflects the research for Fish oil (omega-3) and that condition specifically.

• B

  Rheumatoid arthritis

  Modestly reduces RA joint pain, morning stiffness and tender joints and can lower NSAID use, as an adjunct to standard therapy.

  2 citation s

  • A meta-analysis of the analgesic effects of omega-3 polyunsaturated fatty acid supplementation for inflammatory joint pain
    Meta-analysis 2007 · Pain · PMID 17335973 · DOI 10.1016/j.pain.2007.01.020
  • Omega-3 Supplements: In Depth
    NCCIH · accessed 2026-06-21
• B

  High blood pressure

  About 3 g/day modestly lowers blood pressure, most in untreated hypertensives.

  2 citation s

  • Omega-3 Polyunsaturated Fatty Acids Intake and Blood Pressure: A Dose-Response Meta-Analysis of RCTs
    Meta-analysis 2022 · Journal of the American Heart Association · DOI 10.1161/JAHA.121.025071
  • Omega-3 Fatty Acids — Health Professional Fact Sheet
    NIH ODS · accessed 2026-06-21
• B

  Depression

  EPA-predominant omega-3 (higher-EPA formulas) gives a small-to-moderate benefit in major depression, clearest as an add-on to antidepressants; pure-DHA products show no clear effect.

  2 citation s

  • Meta-analysis and meta-regression of omega-3 polyunsaturated fatty acid supplementation for major depressive disorder
    Meta-analysis 2016 · n=1,233 · Translational Psychiatry · PMID 26978738 · DOI 10.1038/tp.2016.29
  • EPA but not DHA appears to be responsible for the efficacy of omega-3 long chain polyunsaturated fatty acid supplementation in depression
    Meta-analysis 2009 · Journal of the American College of Nutrition · PMID 20439549 · DOI 10.1080/07315724.2009.10719785
• C

  Fatty liver disease (NAFLD)

  May modestly reduce liver fat, but no clear effect on liver enzymes or histology.

  2 citation s

  • Omega-3 polyunsaturated fatty acids and nonalcoholic fatty liver disease in adults: a meta-analysis of RCTs
    Meta-analysis 2025 · n=1,615 · Clinical Nutrition · PMID 40441053 · DOI 10.1016/j.clnu.2025.04.030
  • Omega-3 Fatty Acids — Health Professional Fact Sheet
    NIH ODS · accessed 2026-06-21
• D

  Age-related macular degeneration

  AREDS2 — the only large purpose-built RCT — found omega-3 did not slow AMD progression at either 5 or 10 years (HR 1.01).

  2 citation s

  • Lutein + zeaxanthin and omega-3 fatty acids for age-related macular degeneration: the Age-Related Eye Disease Study 2 (AREDS2) randomized clinical trial
    Randomized trial 2013 · n=4,203 · JAMA · PMID 23644932 · DOI 10.1001/jama.2013.4997
  • Long-term outcomes of adding lutein/zeaxanthin and omega-3 fatty acids to the AREDS supplements on AMD progression: AREDS2 report 28
    Cohort study 2022 · n=3,882 · JAMA Ophthalmology · PMID 35653117 · DOI 10.1001/jamaophthalmol.2022.1640
• —

  Atopic dermatitis (eczema)

  One small pilot trial of high-dose DHA hinted at improvement, but the Cochrane review of supplements found no convincing benefit for eczema — too little to recommend.

  2 citation s

  • Docosahexaenoic acid (DHA) supplementation in atopic eczema: a randomized, double-blind, controlled trial
    Randomized trial 2008 · n=53 · British Journal of Dermatology · PMID 18241260 · DOI 10.1111/j.1365-2133.2007.08430.x
  • Dietary supplements for established atopic eczema
    Systematic review 2012 · n=596 · Cochrane Database of Systematic Reviews · PMID 22336810 · DOI 10.1002/14651858.CD005205.pub3