MADRID, Sept. 2 (UPI) -- A meta-analysis by researchers in Spain indicates selenium may help decrease bladder cancer risk.
Study leader Dr. Nuria Malats of the Spanish National Cancer Research Center in Madrid says dietary sources of this essential micronutrient include plants grown in selenium-rich soils or animals that graze on the soils -- as well as selenium-enriched products.
The study, published in Cancer Epidemiology, Biomarkers & Prevention, suggests selenium may reduce the risk of bladder cancer by 39 percent.
"The lower the levels of selenium, the higher the risk of developing bladder cancer," Malats says in a statement.
Malats notes selenium's effects vary among individuals. The protective effect of selenium's seems gender-specific, as women seem to benefit more -- perhaps due to differences in how the mineral accumulates and is excreted.
Malats and colleagues conducted a meta-analysis of seven studies -- mostly from the United States, but also from Belgium, Finland and the Netherlands. Selenium levels were measured in serum and toenails.
"Although our results suggest a beneficial effect of high selenium intake for bladder cancer risk, more studies are needed to confirm these findings before an enforcement of high selenium intake is recommended," Malats says.