Stroke is a leading cause of death in the United States, leaving many with disabilities affecting everyday living if survived. Stroke is somewhat preventable due to several modifiable risk factors that can be attenuated through lifestyle choices. Traditional nutrition recommendations to reduce the risk of stroke have focused on increasing fiber intake and restricting sodium, saturated fat, and cholesterol. However, there may be another nutrition consideration that is often overlooked that can make a significant difference.



Strokes, like heart attacks, are a type of heart and blood vessel disease. Over time, fatty deposits called plaque build up in the walls of the arteries (known as atherosclerosis), which can reduce blood flow to the heart or brain. Plaques may become unstable and rupture, increasing the risk of clots that can completely block blood flow (ischemic stroke) or lead to internal bleeding (hemorrhagic stroke).

Heart attacks occur when blood flow to a part of the heart is blocked, and strokes occur when blood flow to a part of the brain is blocked. When this happens, the affected part of the brain will stop receiving oxygen and nutrients delivered by the blood, and the brain cells can begin to die within minutes.

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A stroke is a medical emergency, and according to the American Heart Association (AHA), it’s crucial to get help fast if any of the following signs or symptoms of a stroke present:

  • Sudden numbness or weakness of the face, arm, or leg, especially on one side of the body
  • Sudden confusion, trouble speaking, or understanding
  • Sudden trouble seeing in one or both eyes
  • Sudden trouble walking, dizziness, loss of balance or coordination
  • Sudden, severe headache with no known cause

There are several known risk factors for stroke, many of which are lifestyle-related and modifiable, such as smoking, high body mass index, low physical activity, hypertension, diabetes, dyslipidemia, and high alcohol consumption.

Several studies (1, 2, 3) have already identified that a low-risk lifestyle can substantially reduce the risk of stroke. Yet, most of these studies were not focused and instead assessed the combination of several health habits such as vegetable and alcohol consumption, physical activity, and smoking. More recent scientific efforts have begun to narrow their focus on one risk factor, specifically on omega-3 effects on cardiovascular outcomes and stroke prevention (1,2,3).


Omega-3s and Stoke Burden

Since the discovery of the shockingly low incidence of coronary heart disease in the Greenland Eskimo population, whose diet is high in marine omega-3 fats, numerous studies have taken place to determine the effects of these powerful fats on cardiovascular outcomes.

While several individual studies have reported relationships, a 2021 systematic review and meta-analysis sought to determine the effectiveness and safety of omega-3 fats on fatal and non-fatal cardiovascular outcomes in adults. Thirty-eight trials were included in the analysis, encompassing over 149,000 patients. The authors reported a moderate certainty of evidence favoring omega-3s for reduced cardiovascular mortality and other cardiovascular outcomes.

Overall, the magnitude of relative reductions in cardiovascular outcomes was more significant in EPA trials vs. EPA + DHA, suggesting different effects of the two omega-3 fats in cardiovascular risk reduction. The authors of this study noted that overall, the population had a relatively low baseline cardiovascular risk, and most studies investigated used omega-3 dosages <4 g/day. Therefore, the magnitude of the effect of omega-3 treatment might increase with patients with a higher baseline cardiovascular risk and who receive higher doses of omega-3 fatty acid treatment.

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Other large trials have found similar results, including the REDUCE-IT trial, which showed that in patients with elevated triglyceride levels, the risk of ischemic events, including cardiovascular death, was significantly lower among those who received 2g of omega-3s twice daily compared to placebo.

Similarly, another paper was published using data from the Framingham Heart Study reported that in 2500 people, total mortality was 35% lower in those with higher intakes of omega-3 fats and concluded that the Omega-3 Index could serve as a marker of overall health in older Americans. Yet, in much of the research available to date the outcomes were broad to include all cardiovascular outcomes, and the relationship between omega-3 intake and stroke was neither investigated nor found to be associated.


Recent Findings Connect Omega-3 Index Levels with Stroke Risk

A brand new study published by O’Keefe et al. pooled analyses across 29 prospective studies to investigate the association between omega-3 status and total, ischemic, and hemorrhagic stroke incidents. Each study analyzed the relationship between blood omega-3 levels and recorded stroke incidence over an average 14-year follow-up period. Over 180,000 individuals across 15 different countries with an average age of 65 were included in the analyses.

When analyzing by quintile, a significant inverse association was observed between DHA, EPA, and EPA + DHA and the risk of total stroke and ischemic stroke. Those in the highest quintile (Q5), defined as those in the highest 20% omega-3 levels, had a 17% lower risk for total stroke than those in the lowest quintile (Q1). Regarding ischemic stroke, specifically, Q5 risk for ischemic stroke was 18% lower for EPA + DHA, 18% lower for EPA, and 16% lower for DHA compared to Q1.

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The median Omega-3 Index for Q5 was ~8%, suggesting that reaching an Omega-3 Index of 8% or greater could be a cardioprotective goal. Yet, research has found that the mean Omega-3 Index in the U.S. is 5.4%. Scientists have calculated that to raise an Omega-3 Index of 5.4% to 8%, it would require ~1,000mg/day of EPA + DHA from food or supplements. However, one might require higher amounts if their baseline Omega-3 Index is lower.

Interestingly, omega-3 levels were not significantly associated with hemorrhagic stroke. Yet, since the CDC reports that up to 87% of all strokes are ischemic strokes, these findings could still have profound public health impacts. Furthermore, since there has historically been concern that higher levels of omega-3s might increase the risk of bleeding, the outcomes of this study contradict that claim. This study demonstrates a favorable effect of omega-3 fats on stroke risk and opened the door to further studies to understand better the mechanisms by which omega-3s protect the brain.


Lower Risk for Stroke by Making Other Healthy Living Choices

As current evidence indicates, increasing the Omega-3 Index may be a clinically significant way to lower the risk of stroke. It’s been proposed that omega-3 fats reduce the risk of cardiovascular disease events through several mechanisms, such as lowering triglyceride risk lipoproteins, stabilizing membranes, altering prostaglandin synthesis, augmenting specialized pro-resolving mediators, and having anti-inflammatory, antiarrhythmic, and antithrombotic actions. The findings of the recent study by O’Keeffe et al. support the American Heart Association’s Science Advisory recommendation to include 1 to 2 seafood meals per week.

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Yet, EPA + DHA are not the only ways to lower risk. According to the CDC, individuals can help prevent stroke by making healthy lifestyle choices and controlling known clinical conditions.

Some of those lifestyle modifications include:

  • Get regular physical activity. Aim for 2 hours and 30 minutes of moderate-intensity aerobic physical activity weekly.
  • Maintain a healthy weight. Medical providers can help determine an appropriate weight for you.
  • Eat a healthy diet high in plant-based foods. Increase fruit, vegetable, and fiber intake, and lower sodium and saturated fat intake.
  • Don’t smoke. Cigarette smoking increases the risk of stroke.
  • Manage other clinical conditions such as high blood pressure, diabetes, and high cholesterol. Each can raise the risk of stroke if not controlled.



Stroke is a significant public health concern and a leading cause of death and disability in the United States. A new study has been published pooling data indicating that increasing omega-3 levels can significantly decrease the risk for ischemic and total stroke incidence. Furthermore, evidence from this study adds to the data that increasing omega-3 levels to a healthy range (~8% Omega-3 Index) does not increase the risk of bleeding. According to the data from this most recent study, an Omega-3 Index of ~8% seems to be the most protective against stroke risk.

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These statements have not been evaluated by the Food and Drug Administration. This test is not intended to diagnose, treat, cure, prevent or mitigate any disease. This site does not offer medical advice, and nothing contained herein is intended to establish a doctor/patient relationship. OmegaQuant, LLC is regulated under the Clinical Laboratory improvement Amendments of 1988 (CLIA) and is qualified to perform high complexity clinical testing. The performance characteristics of this test were determined by OmegaQuant, LLC. It has not been cleared or approved by the U.S. Food and Drug Administration.

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