CAN OMEGA-3 FATTY ACID REDUCE THE RISK OF STROKE?

Yes, omega-3 fatty acids may help reduce the risk of stroke, particularly ischemic stroke, but the evidence depends on whether we are talking about omega-3 obtained from food or omega-3 supplements.

What the evidence shows

Higher blood levels of EPA and DHA have been associated with lower stroke risk. A large pooled analysis of 183,291 people from 29 prospective cohorts found that people with the highest EPA levels had about a 17% lower risk of total stroke and 18% lower risk of ischemic stroke compared with those with the lowest levels. Higher DHA levels were associated with about 12% lower total stroke risk and 14% lower ischemic stroke risk. No significant association was found with hemorrhagic stroke. (PubMed)

The American Heart Association recommends eating fish, particularly fatty fish, at least twice a week, as part of a heart-healthy diet, and notes that seafood omega-3 intake is associated with a lower risk of ischemic stroke. (professional.heart.org)

But there is an important distinction

Eating fish ≠ taking fish-oil capsules.

Evidence that routinely taking standard-dose EPA+DHA supplements prevents stroke in otherwise healthy people is much less convincing. The AHA has noted that randomized trials have not established a clear stroke-prevention benefit from routine fish-oil supplementation for the general population. (professional.heart.org)

There is stronger evidence for prescription-dose EPA (icosapent ethyl) in selected people at high cardiovascular risk, where reductions in major cardiovascular events—including stroke—have been observed. (PubMed)

Why might omega-3 help?

EPA and DHA may contribute to stroke prevention by:

EPA/DHA →

• ↓ triglycerides
• ↓ inflammation
• improved endothelial function
• modest ↓ blood pressure
• improved arterial function
• potentially less thrombotic tendency

These effects could reduce the likelihood of an ischemic stroke, which occurs when a blood vessel supplying the brain becomes blocked.

Bottom line

Yes, omega-3 is associated with a lower risk of ischemic stroke, but it should not be considered a stand-alone stroke-prevention treatment. The strongest practical evidence supports eating fatty fish regularly as part of a healthy diet. (professional.heart.org)

For stroke prevention, controlling blood pressure, LDL cholesterol, diabetes, smoking, obesity and atrial fibrillation generally has a much larger proven impact than taking an ordinary fish-oil supplement. The 2024 AHA/ASA primary prevention guideline emphasizes management of these established risk factors and healthy dietary patterns. (professional.heart.org)