Vitamin E types and prostate

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J Natl Cancer Inst. 2000 Dec 20;92(24):2018-23. Related Articles,

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J Natl Cancer Inst. 2000 Dec 20;92(24):1966-7.

Association between alpha-tocopherol, gamma-tocopherol, selenium, and

subsequent prostate cancer.

Helzlsouer KJ, Huang HY, Alberg AJ, Hoffman S, Burke A, Norkus EP,

JS, Comstock GW.

Department of Epidemiology, The s Hopkins School of Hygiene and

Public Health, Baltimore, MD 21205, USA. Khelzlso@...

BACKGROUND: Selenium and alpha-tocopherol, the major form of vitamin

E in supplements, appear to have a protective effect against prostate

cancer. However, little attention has been paid to the possible role

of gamma-tocopherol, a major component of vitamin E in the U.S. diet

and the second most common tocopherol in human serum. A nested case-

control study was conducted to examine the associations of alpha-

tocopherol, gamma-tocopherol, and selenium with incident prostate

cancer. METHODS: In 1989, a total of 10,456 male residents of

Washington County, MD, donated blood for a specimen bank. A total of

117 of 145 men who developed prostate cancer and 233 matched control

subjects had toenail and plasma samples available for assays of

selenium, alpha-tocopherol, and gamma-tocopherol. The association

between the micronutrient concentrations and the development of

prostate cancer was assessed by conditional logistic regression

analysis. All statistical tests were two-sided. RESULTS: The risk of

prostate cancer declined, but not linearly, with increasing

concentrations of alpha-tocopherol (odds ratio (highest versus lowest

fifth) = 0.65; 95% confidence interval = 0.32--1.32; P(trend) =.28).

For gamma-tocopherol, men in the highest fifth of the distribution

had a fivefold reduction in the risk of developing prostate cancer

than men in the lowest fifth (P:(trend) =.002). The association

between selenium and prostate cancer risk was in the protective

direction with individuals in the top four fifths of the distribution

having a reduced risk of prostate cancer compared with individuals in

the bottom fifth (P(trend) =.27). Statistically significant

protective associations for high levels of selenium and alpha-

tocopherol were observed only when gamma-tocopherol concentrations

were high. CONCLUSIONS: The use of combined alpha- and gamma-

tocopherol supplements should be considered in upcoming prostate

cancer prevention trials, given the observed interaction between

alpha-tocopherol, gamma-tocopherol, and selenium.

PMID: 11121464 [PubMed - indexed for MEDLINE]