Last week a customer called and said, “I’m having a colonoscopy on May 20th, and I was told that I needed to get off all blood thinning medication, aspirin and fish oil. What’s the deal?”
These admonishments have been standard protocol before any medical procedure for many years. After all, omega-3 fish oil and cod liver oil have a blood thinning effect – one of the properties that make these oils useful in blood clot prevention.
Because of this effect, it has long been believed that fish oil may cause a person to bleed more easily, especially if consumed at higher doses. However, clinical trials have not found much evidence to support it. And just like the longtime airline industry rule about turning off all electronic equipment during a flight, some researchers and physicians are now questioning whether the precaution is valid.
Bill Harris, one of the leading authorities in omega-3 research, doesn’t think so (1).
In 2007, Harris reviewed 19 clinical studies involving 4387 surgical patients who were taking fish oil supplements in doses ranging from 1.6g EPA/DHA per day (the equivalent of taking about 4 fish oil capsules or 1.5 teaspoons of Omega Cure) to 21g EPA/DHA per day. In 16 out of 19 studies, the patients were also taking aspirin. And in three of the studies, patients were taking heparin, another common blood thinning drug. The review concluded that the risk of problematic bleeding was virtually nonexistent, even when combined with other medications known to increase the risk of bleeding (2).
Another review from 2008 reached the same conclusion. This review stated that no published studies had reported clinically significant bleeding episodes among patients treated with antiplatelet drugs and fish oil at a dose of 3g to 7g per day (2).
A more recent review, published online in March of 2017, agreed again. This review found it safe to consume omega-3 supplements, even at large doses of up to 10g of EPA/DHA per day in the short term (3). To put that dose in perspective, it would be same as swallowing almost ¼ cup of Omega Cure, or taking 30 fish oil capsules daily. That’s significantly more omega-3 than anybody takes on a regular basis.
Looking at the clinical reviews, there’s not much evidence to support the need for stopping an omega-3 regimen before surgery. On the flip side, there is research suggesting fish oil could have benefits for patients before and after operations.
When fish oil supplements are used as clinically indicated, the potential benefits outweigh the theoretical excessive bleeding risks for the vast majority of people. For instance, let’s look at how omega-3 could impact the risk of infections, heart complications, and overall hospital stay — common concerns for patients facing surgery.
One meta review analyzed the data on omega-3 supplementation on patients with colon cancer before and after operation. Colon cancer operations are especially dreaded because of the high risk of postoperative infections. The authors of the meta analysis found that omega-3 supplementation was associated with fewer post-surgical infections, as well as a shorter hospital stay (4).
In another review, the authors looked at how omega-3 supplementation impacted cardiac surgery patients. Here again, the authors found that omega-3 supplementation reduced the length of the hospital stay as well as the risk of atrial fibrillation (5).
Other studies have looked at the impact of fish oil-enriched parenteral nutrition. They found that for patients undergoing abdominal surgery, it improved clinical outcomes (6).
You and your physician should decide whether or not it is necessary for you to stop using fish oil supplements before having a medical procedure or surgery.
As Harold E. Bays, MD, recommended in the American Journal of Cardiology, when it comes to fish oil, “the theoretical increase in bleeding risk” needs to be weighed against the potential benefits of using fish oil (7).
When your doctor gives the go ahead, continue taking your full dose of fresh, full-spectrum liquid fish oil every day. As the research above indicates, getting an effective omega-3 dose can help speed up your road to recovery. Not to mention, it could help ease post-procedure aches and pains. For more information on that, read “An Omega-3 Strategy for Pain Relief.”
1. Harris, W.S. Expert opinion: Omega-3 fatty acids and bleeding—Cause for concern? Report of the National Lipid Association’s Safety Task Force: The Nonstatins. 99.6A (2007): 44C-6C. March 19, 2007.
2. Braun, L. Fish oils and bleeding: ‘Is there a clinically significant risk? BioCeuticals. August 19, 2013.
3. Jeansen,S., Witkamp, R.F., Garthoff, J.A., van Helvoort, A., Calder, P.C. Fish oil LC-PUFAs do not affect blood coagulation parameters and bleeding manifestations: Analysis of 8 clinical studies with selected patient groups on omega-3-enriched medical nutrition. Clinical Nutrition (2017). pii: S0261-5614(17)30118-8.
4. Xie, H., & Chang, Y. Omega-3 polyunsaturated fatty acids in the prevention of postoperative complications in colorectal cancer: a meta-analysis. OncoTargets and Therapy 9 (2016): 7435–7443.
5. Langlois, P.L., Hardy, G., Manzanares, W. Omega-3 polyunsaturated fatty acids in cardiac surgery patients: An updated systematic review and meta-analysis. Clinical Nutrition (2017) Jun; 36(3):737-746.
6. Chen, B. et al. Safety and efficacy of fish oil-enriched parenteral nutrition regimen on postoperative patients undergoing major abdominal surgery: a meta-analysis of randomized controlled trials. Journal of Parenteral and Enteral Nutrition (2010). Jul-Aug; 34(4):387-94.
7. Bays, H.B. Safety considerations with omega-3 fatty acid therapy. The American Journal of Cardiology (www.AJConline.org). Vol 99 (6A) March 19, 2007.