Author
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Burri, Betty |
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Submitted to: Book Chapter
Publication Type: Book / Chapter Publication Acceptance Date: 11/18/2005 Publication Date: 2/15/2006 Citation: Burri, B.J. 2006. Recent Research on Vitamin E and Prostate Cancer. Book Chapter, Nova Science Publishers In: Vitamin E: Research, ISBN 1-59454-970-2, pp.1-12. Interpretive Summary: A review of the scientific literature suggests that there is good experimental evidence that vitamin E, and especially its derivative vitamin E succinate, can inhibit prostate cancer progression in many cell cultures and animal models. The mechanisms by which vitamin E could decrease prostate cancer remain unknown, but there is accumulating evidence for several reasonable mechanisms. The evidence that suggests that gamma-tocopherol is more protective than alpha-tocopherol is interesting but far from conclusive. There is some evidence to suggest that men with higher serum vitamin E concentrations and those taking vitamin E supplements have a decreased risk of prostate cancer, but this evidence is weak and the results differ depending on the study design and the population studied. The evidence that vitamin E might prevent prostate cancer is strongest in smokers, and indeed there is little evidence at this time that vitamin E supplements benefit non-smokers. There have been few studies of the dose-response of vitamin E, and there is no consensus on a safe or effective dose for prostate cancer prevention. Finally, a report that vitamin E supplementation resulted in higher rates of heart failure in a high risk group of people with cardiovascular disease or diabetes with cardiovascular risk means that long-term vitamin E supplementation should be approached with caution. Technical Abstract: Vitamin E, its metabolites or its analogs, might help prevent prostate cancer initiation or progression. Prostate cancer is the most common non-skin malignancy and the second leading cause of cancer deaths among men in the United States, exceeded only by lung cancer. About 218,890 new cases of prostate cancer are predicted in the U.S. in the year 2007, and about 27,000 men will die of this disease. Recently, interest in the role of vitamin E as a prostate cancer preventative has increased because of the unplanned results of two large cancer prevention trials: the Alpha-Tocopherol Beta-Carotene trial to prevent lung cancer in Finnish smokers, and the Nutritional Prevention of Cancer trial of selenium and vitamin E against non-melanoma skin cancer in the United States. Both trials resulted in significantly decreased prostate cancer. Laboratory tests and animal models suggest that vitamin E, or especially its derivative vitamin E succinate (VES) may act to prevent prostate cancer initiation or inhibit its progression through several mechanisms: by protecting against oxidative damage, inducing apoptosis, decreasing DNA adduct formation, interfering with the function of the androgen receptor, inhibiting cyclooxygenase-2, inhibiting angiogenesis, or by stimulating T-cell dependent immune functions. These findings led to the testing of vitamin E and selenium specifically to prevent prostate cancer in the SELECT trial to prevent prostate cancer in 32,000 U.S. men, which will be completed in 2013; however, the potential of vitamin E to prevent prostate cancer remains debatable, especially in non-smokers. |
