Can Omega-3 Fatty Acids Reduce Heart Disease?

Omega-3 fatty acids have long been promoted for heart health, but the evidence has been mixed. Recent research has helped clarify when and how these supplements may benefit cardiovascular health.

Types of Omega-3 Fatty Acids

There are three main types of omega-3s:

EPA (Eicosapentaenoic acid): Found primarily in fatty fish and fish oil.
DHA (Docosahexaenoic acid): Also found in fatty fish and fish oil.
ALA (Alpha-linolenic acid): Found in plant sources like flaxseed, walnuts, and canola oil.

What the Evidence Shows

Research on omega-3s and heart health has yielded important findings:

High-Dose EPA: The REDUCE-IT trial showed that high-dose EPA (4 grams daily of icosapent ethyl) reduced cardiovascular events by 25% in high-risk patients with elevated triglycerides already on statins.
Standard Fish Oil: Most studies of typical fish oil supplements (1-2 grams containing both EPA and DHA) have not shown significant cardiovascular benefit.
Triglyceride Reduction: Omega-3s effectively lower triglyceride levels, particularly in people with very high levels.

Prescription vs. Over-the-Counter

There's an important distinction:

Prescription Omega-3s: Highly purified, contain specific doses of EPA alone or EPA/DHA. Vascepa (icosapent ethyl) is FDA-approved to reduce cardiovascular risk.
OTC Fish Oil: Variable quality and composition. Not regulated as strictly as prescription products. Generally not recommended for cardiovascular risk reduction.

Who Might Benefit?

Prescription high-dose EPA may be considered for patients who:

Have established cardiovascular disease
Have diabetes with additional risk factors
Are already on maximally tolerated statin therapy
Have elevated triglycerides (150-499 mg/dL)

The Best Source: Food

Regardless of supplement decisions, eating fatty fish remains beneficial:

Aim for at least two servings of fatty fish per week.
Good choices include salmon, mackerel, sardines, and herring.
Fish provides omega-3s along with protein and other nutrients.
Plant sources like walnuts and flaxseed provide ALA omega-3s.

Potential Risks

High-dose omega-3s are generally safe but may cause:

Fishy aftertaste or burping
Gastrointestinal upset
Increased bleeding risk in some patients
Atrial fibrillation (a risk seen in some studies at very high doses)

The Bottom Line

While standard fish oil supplements haven't proven beneficial for most people, prescription high-dose EPA (Vascepa) can reduce cardiovascular events in high-risk patients with elevated triglycerides. Talk to your cardiologist about whether prescription omega-3 therapy is appropriate for your situation.