Scientists Dr. Ulrike Peters, of the Fred Hutchinson Cancer Research Center, Seattle, and colleagues have come out with findings that show serum selenium or levels of selenium in the blood is not that positively correlated with reduced risks of prostate cancer as previously thought.
Previous studies have reported that the mineral is associated with reducing the risk of prostate and lung cancer, as well as boosting the immune system.
Over half a million new cases of prostate cancer are diagnosed every year world wide, and the cancer is the direct cause of over 200,000 deaths.
More worryingly, the incidence of the disease is increasing with a rise of 1.7 per cent over 15 years.
Yet the research published in The American Journal of Clinical Nutrition does account for a significant influence of higher levels of serum selenium on certain men.
These subgroups are those men who have a high intake of vitamin E or multivitamins or who are smokers.
The team compared selenium in blood samples collected before diagnosis from 724 subjects who developed prostate cancer and from a comparison group of 879 similar men who remained free of the disease.
All participants completed a questionnaire at enrollment regarding age, ethnicity, education, occupation, smoking history, history of cancer and other diseases, use of selected drugs, and prostate related health factors.
A 137-item food-frequency questionnaire was used to assess usual dietary intake over the 12 months before enrollment. The men were followed for up to 8 years.
The results showed a reduction by 42 percent in risks of getting prostate cancer by those who took more than 28 IU of vitamin E.
For those who took multivitamins daily, the risk reduction was 39 percent.
For smokers it was good news. Those smokers with high serum selenium were observed to have a 35 percent reduced risk of developing prostate cancer.