DIM or diindolylmethane is a common ingredient that is used for supplements. It is a metabolite of indole-3-carbinol and is abundantly present in healthy vegetables such as broccoli, cabbage, cauliflower, and kale. Cancer patients often try to add random dietary supplements to their ongoing cancer treatment to improve their quality of life or treatment effect, assuming that it is always safe to take any natural or plant-based supplements during their ongoing treatment. Will not cause harm. This is not always the case. Depending on the type of cancer and treatment method, the effects of these supplements may vary and may even interfere with specific cancer treatments.

Breast cancer patients receive adjuvant tamoxifen endocrine therapy for 5-10 years after surgery, radiotherapy, and chemotherapy. Studies have found that DIM interferes with tamoxifen and reduces the level of tamoxifen's active metabolites. The interaction between DIM and tamoxifen may affect the therapeutic effect of tamoxifen. Therefore, it is best not to take DIM supplements as part of your diet during tamoxifen treatment.

However, diindolylmethane as part of the daily diet can effectively prevent the risk of breast cancer and the probability of cancer recurrence. According to case-control and research shows. The cruciferous vegetables rich in indole-3-carbinol in the diet will reduce the risk of breast cancer by 15%.

In summary, it is best to avoid taking DIM in breast cancer patients receiving tamoxifen. A plant-based diet, including cruciferous vegetables containing indole-3-carbinol, may be more beneficial than taking it during hormone therapy for breast cancer.