Olive Oil and Breast Cancer: What to Know

Olive oil is generally considered safe for people with breast cancer, and it fits well within a Mediterranean-style eating pattern that emphasizes healthy fats, vegetables, fruits, legumes, and fish. ^[1] Choosing healthy plant oils like olive oil can be part of a balanced approach to nutrition during and after breast cancer treatment. ^[2]

Is Olive Oil Safe?

• Olive oil is a source of healthy fats (monounsaturated fats) and can be included as part of a nutritious diet for individuals with breast cancer. ^[1] Diets that include healthy plant oils, such as olive oil, are linked with overall health benefits and may lower the risk of some diseases. ^[2]
• There are no known direct harmful interactions between olive oil and common breast cancer treatments like chemotherapy, tamoxifen, or aromatase inhibitors. ^[3] Guidance on treatment-related food interactions typically highlights grapefruit as a concern with tamoxifen, not olive oil. ^[3]

Potential Benefits

• A Mediterranean-style diet pattern that uses extra-virgin olive oil (EVOO) as the main fat source is associated with favorable health outcomes and has been linked to lower risk of certain chronic diseases. ^[4] This pattern emphasizes vegetables, beans, fruits, seafood, and healthy plant oils like olive oil. ^[2]
• Observational research suggests a possible inverse association between olive oil intake and breast cancer risk, though the certainty is low and findings are not definitive; more high-quality prospective studies are needed. [PM14] Reviews highlight bioactive compounds in extra-virgin olive oil such as polyphenols that may have antioxidant and anti-inflammatory effects relevant to breast health, but clinical evidence on recurrence and survival remains limited. [PM19]

During Treatment

• If appetite is low during chemotherapy or hormonal therapy, adding healthy fats like olive oil can help boost calories and make foods more palatable. ^[5] Practical tips include small, frequent meals and enriching dishes with olive oil for energy without excessive volume. ^[5]
• Choosing healthy fats over saturated and trans fats is encouraged to support cardiovascular health, which is important during and after cancer care. ^[6] Opting for olive oil instead of butter aligns with these recommendations. ^[4]

Practical Tips for Using Olive Oil

• Prefer extra-virgin olive oil for dressings and finishing dishes to preserve its polyphenols. [PM19]
• Use olive oil to sauté vegetables, dress whole grains and legumes, and pair with fish key elements of a Mediterranean-style eating pattern. ^[2]
• Balance calories: fat is energy-dense, so use moderate portions to support a healthy weight, which is important for breast cancer prevention and survivorship. ^[4]

What Olive Oil Does Not Do

• Olive oil is not a cure or a standalone preventive for breast cancer; cancer risk and outcomes involve many factors beyond diet. ^[7] No single food can prevent or treat cancer on its own, and olive oil should be part of an overall balanced diet and regular medical care. ^[7]

Key Precautions and Interactions

• Grapefruit and grapefruit juice can interact with tamoxifen; avoiding grapefruit is advised if you take tamoxifen. Olive oil does not share this interaction. ^[3]
• If you are on hormonal therapies, continue to follow your treatment plan and medication guidance; dietary changes should complement, not replace, medical therapy. ^[3]

Bottom Line

• Olive oil is safe for most people with breast cancer and can be a healthy choice, especially within a Mediterranean-style diet that emphasizes plant-forward foods and fish. ^[1] While emerging research suggests potential benefits, the evidence on breast cancer risk reduction and survival is not conclusive, so olive oil should be viewed as part of a broader healthy eating pattern and lifestyle. [PM14]