Sostanzialmente:
For years nobody knew exactly how saw palmetto worked, but we now know that it shrinks the prostate gland by killing prostate cells—both malignant and healthy cells. Surprisingly, while saw palmetto is selectively toxic to prostate cells and prostate cancer cells, it has not been researched as a treatment for prostate cancer.
Three recent studies investigating the effectiveness and effect of saw palmetto on prostate tissue came up with the same conclusion: Saw palmetto has an effect similar to chemotherapy on prostate cells—it kills both unhealthy and healthy cells!