14 DAY TRIAL // Selenium intake is linked with a decrease in risk of bladder cancer, announces a study published in the September issue of Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.
The lead researcher on the study was Núria Malats, MD, PhD, leader of the Genetic and Molecular Epidemiology Group, Human Cancer Genetics Program, Spanish National Cancer Research Center.
The team used data from seven previously published studies to carry on a meta-analysis so that they could see if there is a link between levels of selenium measured in serum and toenails, and the risk of developing bladder cancer.
This data came mostly from subjects From the United States, but also from individuals in Finland, Belgium and the Netherlands.
The results of this analysis showed that selenium had a protective affect, especially among women – scientists believe it is due to the gender-specific differences that concern the mineral's accumulation and excretion in women.
Still, Malats said that “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.”
Selenium is a micronutrient contained by 25 proteins inside the body - called selenoproteins, most of which are enzymes that have antioxidant properties, and prevent cellular damage caused by the by-products of oxygen metabolism.
The possible selenium sources are plant foods grown in selenium-rich soils, meat of animals who pasture on these soils and also selenium-enriched products.
All of these are recommended because “the lower the levels of selenium, the higher the risk of developing bladder cancer,” as Núria Malats said.
Elizabeth A. Platz, Sc D, MPH, an Editorial Board Member of Cancer Epidemiology, Biomarkers & Prevention, said that “these findings provide a valuable lead for what to do next to understand if there is a role for selenium supplementation in bladder cancer prevention.”
But before giving any advice or recommendations at a wide scale, the dose-response relationship needs further investigation.
This is a matter of public health importance and knowing what daily intakes to recommend is very important, as well as targeting subsets of the population for selenium supplementation, Platz added.
Platz is also a professor in the department of epidemiology at Johns Hopkins Bloomberg School of Public Health.