From the Guidelines
Fish oil supplements do not need to be stopped before surgical procedures, as prior concerns about bleeding risk have not been borne out in prospective studies. The most recent and highest quality study, published in 2021 in the Mayo Clinic Proceedings 1, recommends that fish oil/omega-3 fatty acid preparations should be continued, as they do not increase the risk of bleeding. This is in contrast to other supplements, such as aloe, arnica, and ginkgo, which should be held for 2 weeks before surgery due to their potential to affect bleeding risk.
Some key points to consider:
- Fish oil contains omega-3 fatty acids that were previously thought to inhibit platelet aggregation and increase bleeding time, but this has not been supported by recent studies 1.
- The American Society of Anesthesiology recommends that dietary supplements be discontinued 1 to 2 weeks before surgery out of maximal precaution, but this recommendation is not supported by evidence for fish oil supplements 1.
- A large placebo-controlled trial found no increase in perioperative bleeding in patients taking fish oil supplements compared to those taking a placebo 1.
- Patients should always discuss their supplement use with their surgeon during pre-operative consultations to determine the best course of action for their individual situation.
In terms of morbidity, mortality, and quality of life, continuing fish oil supplements before surgery is unlikely to increase the risk of bleeding and may even have beneficial effects on cardiovascular health. Therefore, patients can typically continue taking fish oil supplements up to the day of surgery, and resume taking them after surgery once their surgeon confirms adequate healing has occurred.
From the Research
Ceasing Fish Oil Prior to Procedures - Bleeding Risk
- The recommended duration for stopping fish oil supplements before a surgical procedure to minimize the risk of bleeding is not clearly established, as several studies suggest that fish oil supplementation does not increase perioperative bleeding and may even reduce the number of blood transfusions 2, 3, 4.
- A systematic review of 52 publications found that fish oil exposure in surgical patients did not increase bleeding or blood transfusions either during or after surgery, and therefore does not support the need for discontinuation of fish oil supplements prior to surgery or other invasive procedures 3.
- A study on the role of fish oil in post-cardiotomy bleeding found that fish oil alone is not capable of producing a clinically significant coagulopathy that would induce or contribute to surgical bleeding, and patients who are taking fish oil without other anticoagulants do not have an increased risk of bleeding surgical complications 5.
- Another study found that n-3 fatty acid treatment had no effect on the risk of clinically significant bleeding in either monotherapy or combination therapy settings, and the use of these fatty acids in several settings improved clinical outcomes 4.
- A retrospective case-control study on spinal decompression surgery found no increase in intraoperative blood loss or postoperative bleeding complications associated with preoperative use of n-3FA supplements up to an average of 2.3 days before surgery 6.
Key Findings
- Fish oil supplementation does not increase perioperative bleeding and may reduce the number of blood transfusions 2, 3, 4.
- Fish oil exposure in surgical patients does not increase bleeding or blood transfusions either during or after surgery 3.
- Patients who are taking fish oil without other anticoagulants do not have an increased risk of bleeding surgical complications 5.
- N-3 fatty acid treatment has no effect on the risk of clinically significant bleeding in either monotherapy or combination therapy settings 4.
- Preoperative use of n-3FA supplements does not increase intraoperative blood loss or postoperative bleeding complications in spinal decompression surgery 6.