Fish oil supplementation and surgery
Ever since Dyerberg et al. showed that the bleeding time among Greenland Inuit was longer than among the Danish and found that platelets in the Inuit had a high concentration of omega-3 polyunsaturated fatty acids (PUFA), the impact of n-3 PUFAs on haemostasis has been the subject of debate. Supplementation with fish oil could inhibit platelet aggregation, potentially increasing the risk of bleeding. Most studies have focussed on primary haemostasis, finding that fish oil supplementation in healthy subjects continues to affect platelet half life (for about 10 days) after it has been discontinued. However, it has also been observed that fish oil has no substantial effect on secondary haemostasis.
A systematic review of 52 studies (32 with healthy subjects and 20 with subjects undergoing surgery), most of them randomised and controlled or with a control group, concludes that although fish oil supplements reduced platelet aggregation in healthy subjects, bleeding or blood transfusions was not higher among subjects undergoing surgery either during or after the procedure. Therefore, discontinuing supplementation before surgery and other invasive procedures is not considered necessary (not even when fish oil supplementation is combined with antithrombotic therapy).