Vitamin E, alpha- and gamma-tocopherol, and prostate cancer.

Vitamin E is one of the most researched compounds in medicine. Vitamin E is actually a general name for potentially eight different compounds, so supplements can contain several forms and vitamin E in the diet also differs from the form found over the counter. There has been a strong interest in this supplement in the prostate cancer arena primarily because of a Finnish study that demonstrated a lower morbidity and mortality from this disease in men taking 50 mg of synthetic (alpha-tocopherol) vitamin E daily. In addition, observations from laboratory and clinical studies dealing with heart disease have found that gamma-tocopherol may also play a significant role in prevention; therefore, we decided to test the ability of this compound (versus synthetic vitamin E) to control the growth of a human prostate cancer cell line. Gamma-tocopherol was found to be superior to alpha-tocopherol in terms of cell inhibition in vitro. Both forms of vitamin E (and others) should be thoroughly evaluated in the future to provide the most effective chemoprevention information to the patient.