Selenium pills a bust for cancer prevention

There's no good evidence that supplemental doses of the mineral selenium can prevent cancer, and some research suggests they might actually pose risks, according to a comprehensive analysis published online this week in The Cochrane Library.

The researchers came to those conclusions after analyzing 49 observational studies involving more than a million participants, and six randomized controlled trials with more than 43,400 subjects. The best trials found that selenium didn't prevent prostate cancer in men and actually increased the risk of non-melanoma skin cancer in women and men, according to the report. Other trials found that participants using selenium supplements had a decrease in liver cancer cases, but the evidence was unconvincing due partly to methodological shortcomings.

Population findings that did seem to show an association between higher selenium levels of intake and lower incidence of some cancers, especially in men, had potential design limitations and data issues. So it was impossible to determine whether selenium was really the reason for the lower risk of cancer in some people, the researchers reported. Other factors, such as healthier nutritional intake or lifestyle, could also have played a role.

Bottom line: Until more is known, you can cut your cancer risk, by quitting smoking, avoiding excessive drinking, and eating a diet that includes a wide range of fruits and vegetables as well as nuts, legumes, and whole grains. And don't forget: Crab, liver, fish, poultry, and wheat are generally good selenium sources.

Source
Selenium for preventing cancer [Cochrane Database of Systematic Reviews]

—Doug Podolsky