Research

Mixed

Marine omega-3 fatty acids (EPA and DHA) reduce the risk of cardiovascular disease, particularly coronary heart disease and sudden cardiac death, primarily through secondary prevention in high-risk patients (e.g., post-myocardial infarction), while evidence for primary prevention in healthy populations remains weak or inconclusive.

If you have heart disease or have had a heart attack, taking 840mg of EPA+DHA daily is a well-supported strategy to reduce mortality. If you are healthy and have no heart disease, taking omega-3 supplements is unlikely to prevent a heart attack, though it may offer other minor benefits. Focus on diet (fatty fish) rather than supplements for primary prevention.

GoodQualifiesHIGH confidence
Evidence for primary prevention of CVD through randomised controlled trials (RCTs) is relatively weak. In high-risk patients, especially in the secondary prevention setting (e.g., post-MI), a number of large RCTs support the use of EPA + DHA (or EPA alone) as confirmed through a recent meta-analysis.
Jacqueline K. Innes et al. · International Journal of Molecular Sciences · 2020

Why this rating

Strong observational data and positive RCTs for secondary prevention, but mixed/negative RCTs for primary prevention.

Source

Marine Omega-3 (N-3) Fatty Acids for Cardiovascular Health: An Update for 2020

Jacqueline K. Innes et al. · International Journal of Molecular Sciences · 2020

DOI 10.3390/ijms21041362

narrative_reviewCited 355×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →