Foods that have natural anticoagulant properties that cause blood thinning include ginger, garlic, aniseed and celery seed, according to Healthline. Foods that contain high levels of vitamin E are also natural blood thinners.
Greens, such as spinach and broccoli, and fruits, such as kiwi and mangoes, are good sources of vitamin E, notes Healthline. Nuts and seeds, such as peanut butter, almonds and sunflower seeds, as well as oils, such as olive, corn, sunflower, soybean and safflower, are heart-healthy fats and natural anticoagulants.
Patients should always consult a doctor before mixing natural blood thinners with prescription medications, as certain interactions can render a medication ineffective, states Healthline. Vitamin K interferes with some anticoagulant medications, including warfarin. Foods that are high in vitamin K include cabbage, Brussels sprouts, endive and asparagus. Green leafy vegetables, such as kale and mustard, turnip, collard and greens, contain moderate-to-high levels of vitamin K.
Herbs may also interact with anticoagulant medications and can increase the risk of bleeding, according to Healthline. Patients should exercise caution when taking herbal supplements or teas, including chamomile, clove, echinacea, licorice and ginseng. Additionally, alcohol has a negative effect on blood thinners, as does cranberry juice. Certain medications may have harmful interactions, including over-the-counter antibiotics, anti-fungal drugs, birth control pills and pain relievers.