Anticoagulant activity of select dietary supplements.

This review considers the potential of certain dietary supplements, including garlic, Ginkgo biloba, ginger, ginseng, fish oil, and vitamin E, to interfere with hemostasis. Dietary supplements are common components of the diet in the United States, with about half the US adult population taking some type of dietary supplement regularly. It has been suggested that some supplements could adversely affect coagulation when taken alone or in combination with antiplatelet medications. Supplements could alter hemostasis by a variety of mechanisms, such as reducing platelet aggregation or inhibiting arachidonic acid, a cellular signaling messenger and inflammatory intermediate. To conduct this review, multiple databases were searched using a variety of search terms to ensure relevant papers were located. Moderate to severe adverse events, such as spinal epidural hematoma, spontaneous intracerebral hemorrhage, retrobulbar hemorrhage, subarachnoid hemorrhage, spontaneous hyphema, and postoperative bleeding, have occasionally been anecdotally associated with consumption of dietary supplements. However, the number of controlled studies in the literature is too limited to demonstrate consistent anticoagulant effects of dietary supplements alone or in combination with drug therapy.