From the Guidelines
Fish oil supplements do not significantly increase the risk of bleeding, and their use can be continued without concern for bleeding complications, as supported by recent prospective studies 1. When considering the use of fish oil supplements, it's essential to weigh the potential benefits against the risks. The evidence suggests that fish oil supplements are generally well-tolerated and do not raise significant safety concerns for adults, even at doses up to 5 g/day of EPA and DHA combined 1. Some key points to consider:
- Fish oil supplements may have a mild anticoagulant effect due to their inhibition of platelet aggregation, but this effect is not typically clinically significant for most people.
- High doses of fish oil (more than 3 grams daily) or concomitant use of blood thinners like warfarin, aspirin, or clopidogrel may require discussion with a healthcare provider before starting supplementation.
- Recent guidelines suggest that fish oil/omega-3 fatty acid preparations can be continued without interruption, even in the preoperative period, as prior concerns about bleeding risk have not been borne out in prospective studies 1.
- The cardiovascular benefits of omega-3 fatty acids often outweigh the minimal bleeding risk for most individuals, making fish oil supplements a potentially valuable addition to a healthy lifestyle.
From the Research
Omega-3 Fatty Acids and Bleeding Risk
- Theoretical concerns have been raised about the potential antithrombotic effect of fish oils increasing the risk for bleeding 2.
- However, clinical trial evidence has not supported increased bleeding with omega-3 fatty acid intake, even when combined with other agents that might also increase bleeding, such as aspirin and warfarin 2, 3, 4, 5.
- A study comparing bleeding complications with omega-3 fatty acids + aspirin + clopidogrel versus aspirin + clopidogrel in patients with cardiovascular disease found no significant difference in major or minor bleeding episodes between the two groups 3.
- Another study found that fish oil supplementation did not increase perioperative bleeding and reduced the number of blood transfusions in patients undergoing cardiac surgery 4.
- A case report described a patient who developed a subdural hematoma after a fall while taking high-dose omega-3 fatty acids with warfarin and aspirin, highlighting the potential risks of combination therapy 6.
- An analysis of 8 clinical studies with selected patient groups on omega-3-enriched medical nutrition found no evidence of increased risk of bleeding with use of n-3 LC-PUFAs, even in patients with moderate to severe disease or concomitant use of antithrombotic agents 5.
Key Findings
- Omega-3 fatty acid supplementation does not appear to increase the risk of bleeding, even when combined with other antithrombotic agents 2, 3, 4, 5.
- Higher achieved n-3-PUFA levels may be associated with lower risk of bleeding 4.
- Fish oil supplementation may reduce the number of blood transfusions in patients undergoing cardiac surgery 4.
- Combination therapy with omega-3 fatty acids and other antithrombotic agents may require judicious use and patient education to minimize bleeding risks 6.