Selenium Plays Role in Cancer Prevention

Cancer prevention may be associated
with the foods you eat.

A study reported in the journal Cancer Epidemiology, Biomarkers & Prevention (September 2010) associates bladder cancer in adults with low blood levels of the mineral selenium.

The analysis of selenium in blood samples from patients in the United States and Europe showed:

• The highest levels of selenium decreased the risk of bladder cancer by 39% (thirty-nine percent)
• Women appear to gain greater benefit from selenium than men

The human diet gets this trace mineral from plant-based foods grown in soil containing selenium content. Animals may contribute selenium to our food supply when they have fed upon plants rich in this mineral or been given selenium-enriched feed.

Little selenium is needed in a normal diet, and too much of this mineral can be dangerous. As much as 400 micrograms a day may be safe, but the recommended daily allowance (RDA) of selenium is only 55 micrograms per day for adults, less for children.

While these recent results suggest that a larger amount of selenium in the diet may improve bladder cancer prevention, no one recommends greatly increasing this mineral in your diet until more studies confirm the data.

Selenium deficiency is rare in most parts of the world. Few geographic areas (certain regions of Russia and China) have such low amounts of selenium in the soil to present dietary deficiency for local populations.

A balanced diet that includes foods high in fiber typically will supply an adequate and safe amount of selenium for your health. And while cancer prevention is important, adding too much selenium to your diet can prove dangerous. Problems may range from an upset stomach and white spots under finger nails, to hair loss, irritability, fatigue, and mild nerve damage.

Fiber foods known to provide this mineral include grains and nuts. The amount of selenium available from food sources depends on the selenium content in the soil where the food was grown. For example, Brazil nuts can contain as much as 544 micrograms of selenium per ounce which could prove dangerous, but often these nuts have much less of the mineral. To be safe, limit consumption of Brazil nuts.

Selenium Sources from Fiber Foods

Refer to the U.S. Department of Agriculture's Nutrient Database web site http://www.nal.usda.gov/fnic/foodcomp/search for additional food sources.