Based on NIH | Is it safe to eat nuts, such as walnuts or almonds, while taking warfarin, or can they affect my INR?

Most people taking warfarin can safely eat common nuts like walnuts and almonds as long as their overall diet is consistent, because the key dietary factor that changes warfarin effect is vitamin K intake and typical servings of these nuts are low in vitamin K. ^[1] Warfarin’s effect is sensitive to changes in diet, medications, and supplements, so keeping your day‑to‑day eating pattern steady and monitoring your INR when making any significant dietary change is important. ^{[2] [3]}

How warfarin and diet interact

• Warfarin has a narrow therapeutic range, and its activity can be altered by dietary vitamin K and other agents, which can shift your INR (a measure of blood thinning). ^[2] After your INR is stabilized, periodic monitoring helps keep dosing in range, especially if diet or medicines change. ^[4]
• The most consistent food effect is from vitamin K–rich foods, which can lower INR if eaten in larger or varying amounts; guidance emphasizes keeping vitamin K intake steady rather than avoiding it completely. ^{[1] [5]}

Where nuts fit in

• Standard lists of foods that strongly affect warfarin focus on leafy greens and certain oils high in vitamin K; nuts are not highlighted among the primary vitamin K–rich foods to avoid or tightly limit. ^{[3] [5]}
• Because guidance centers on consistency, including small to moderate, regular portions of nuts is generally considered acceptable for many people on warfarin. ^[1] Keeping a consistent pattern helps avoid INR swings. ^[2]

Potential indirect considerations

• Large shifts in any vitamin K source (for example, suddenly adding many servings of vitamin K–rich foods or certain vegetable oils) can lower INR; some nuts are prepared with oils that contain vitamin K, so sudden increases in such snacks could theoretically matter. ^[3]
• Botanical and herbal products can unpredictably interact with warfarin; if nuts are consumed as part of herbal/functional mixes or fortified products, closer INR monitoring is wise when starting or stopping them. ^{[6] [7]}

Practical tips for eating nuts on warfarin

• Aim for consistency: if you enjoy nuts, try similar portion sizes and frequency each week rather than big swings. ^[1]
• Watch for packaged nut mixes with added greens powders, herbal extracts, or high‑vitamin‑K oils; if you add or remove these, arrange an INR check. ^{[6] [3]}
• Remember that other supplements (for example, vitamin E in high doses or certain botanicals) and many medications can affect INR; always inform your care team about new products. ^{[8] [9]}

When to seek INR checks

• If you plan a noticeable dietary change (e.g., starting daily nut butters made with soybean oil or adding large amounts of salads, juices, or herbal products), it’s reasonable to check your INR sooner to ensure it stays in range. ^{[3] [4]}
• Any unexplained bleeding, bruising, or signs of over‑ or under‑anticoagulation should prompt timely evaluation and INR testing. ^[3]

Bottom line

• Walnuts, almonds, and other common nuts do not appear among the main foods known to consistently disrupt warfarin, and most people can include them in moderation. Keeping intake steady from week to week is the priority so that your INR remains stable. ^{[5] [1]}
• Because warfarin is sensitive to overall diet and supplements, coordinate any notable dietary changes with your healthcare team and maintain regular INR monitoring. ^{[2] [4]}