The modulation of prostate cancer risk with alpha-tocopherol: a pilot randomized, controlled clinical trial

J Urol. 2005 Aug;174(2):519-22. doi: 10.1097/01.ju.0000165151.08560.6a.

Abstract

Purpose: Studies suggest that vitamin E may decrease the risk of prostate cancer. The Prevention Research Veteran Affairs E-vitamin Nutrition Trial is a randomized, double-blind, placebo controlled study designed to assess the effects of vitamin E supplementation on biomarkers associated with prostate cancer risk in peripheral blood and prostate tissue.

Materials and methods: A total of 44 patients with increased prostate specific antigen (PSA) and/or abnormal digital rectal examination on initial evaluation were randomized to receive 400 IU vitamin E (22) vs placebo (22). Serum vitamin E, PSA, dehydroepiandrosterone, testosterone and insulin-like growth factor-1 (IGF-1) were measured in the 2 groups at baseline and then at 3-month intervals. Results are reported in 28 patients (placebo in 14 and vitamin E in 14) who completed the treatment as specified by the protocol.

Results: Serum Vitamin E was significantly higher in patients on vitamin E supplementation. alpha-Tocopherol supplementation did not affect the levels of PSA, serum androgens (testosterone and dehydroepiandrosterone) or (IGF-1).

Conclusions: Serum alpha-tocopherol is increased by oral supplementation of vitamin E. We found that alpha-tocopherol supplementation has no effect on serum androgens, IGF-1 or PSA. The lack of an effect of vitamin supplementation on PSA avoids any bias in the diagnosis of prostate cancer in vitamin E treated patients. Our results suggest that a decrease in prostate cancer risk with alpha-tocopherol is likely to occur through a mechanism that is nonhormonal and independent of IGF-1.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Antioxidants / metabolism
  • Dehydroepiandrosterone / blood
  • Dietary Supplements
  • Humans
  • Insulin-Like Growth Factor I / analysis
  • Male
  • Pilot Projects
  • Prospective Studies
  • Prostate-Specific Antigen / blood
  • Prostatic Neoplasms / prevention & control*
  • Testosterone / blood
  • Vitamin E / therapeutic use*
  • alpha-Tocopherol / blood

Substances

  • Antioxidants
  • Vitamin E
  • Testosterone
  • Dehydroepiandrosterone
  • Insulin-Like Growth Factor I
  • Prostate-Specific Antigen
  • alpha-Tocopherol