The study by Ulrike Peters and colleagues from the Cancer Prevention Program, Fred Hutchinson Cancer Center, Seattle, WA and other organizations found that the possible benefit was not for every man studied, but only for those who reported a high vitamin E intake and those taking multivitamins.

Early studies have found that high serum levels of selenium were linked with reduced risk of prostate cancer.   A study published in a December 2001 issue of The Journal of Urology found that low levels of serum selenium was associated with a 4 to 5-fold increased risk of prostate cancer.

The current study, published in the Jan. 12007 issue of American Journal of Clinical Nutrition meant to examine interrelations between selenium as an antioxidative agent and oxidative stressors such as smoking and also to see if serum selenium is linked with lower risk of prostate cancer.

In the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, 724 incident prostate cancer case subjects and 879 control subjects were followed for eight years.   Blood samples were collected to analyze selenium levels in the blood.  Subjects were surveyed before entering the study for their dietary habits.

The researchers found that overall there was no association between serum selenium and prostate cancer risk in the cohort.

However, those in the highest quartile of serum selenium who reported a high vitamin E intake experienced a 42 percent reduced risk of prostate cancer compared to those in the lowest.

Among men who used multivitamins, those in the highest quartile of selenium in their blood were 39 percent less likely to develop prostate cancer.

Strangely enough, among the smokers, the high serum selenium was linked to a 35 percent reduced risk of prostate cancer.

The study did not intend to establish a causal relation between serum selenium and prostate cancer. Nor did the results suggest that taking selenium supplements would or would not reduce risk of prostate cancer.

Regardless, selenium is recognized as an antioxidant that helps prevent cells from being damaged by free radials generated by the normal metabolism. Free radials can cause damage to DNA leading to development of cancer.

The Daily recommended allowance for selenium is 55 micrograms per day for both men and women. Selenium is found abundant in Brazil nuts.   Foods such as shrimp, crab meat, salmon, halibut, and brown rice also contain rich amounts of selenium.

Source:

Ulrike Peters, Charles B Foster, Nilanjan Chatterjee, Arthur Schatzkin, Douglas Reding, Gerald L Andriole, E David Crawford, Stefan Sturup, Stephen J Chanock, and Richard B Hayes

Serum selenium and risk of prostate cancer—a nested case-control study
Am J Clin Nutr 2007 85: 209-217.