Can patients with breast cancer consume natto?
Generally, breast cancer develops when breast cells grow uncontrollably. The breast contains lobules—glands that produce milk—and ducts—tubes that carry milk to the nipple. Most breast cancers originate in either the ducts or the lobules. Additionally, rare breast tumors—including phyllodes tumors and angiosarcomas—also fall under the umbrella of breast cancer. So, can breast cancer patients consume natto? Below, we address this question.
Can breast cancer patients eat natto?
Natto is a fermented food made from soybeans and thus classified as a soy-based product. It is safe for breast cancer patients to consume.

Breast cancer patients are encouraged to moderately supplement their diet with high-quality protein sources. Dairy products and soy-based foods—such as tofu, soy milk, and other soy derivatives—are excellent choices rich in high-quality protein.
Moreover, patients are advised to adopt healthy dietary and lifestyle habits: increase intake of fresh vegetables and fruits; incorporate whole grains and mixed cereals appropriately; maintain regular meal schedules and avoid overeating or binge eating. Patients should also limit consumption of organ meats (e.g., liver, kidney) and engage in regular physical activity to maintain a healthy body weight.
We hope the above information is helpful to you.