Immunity: The incredible therapeutic powers of selenium

You could call it the vitamin E helper.

Ive told you before how a metallic trace element called selenium boosts the antioxidant power of vitamin E. And if that were all selenium did, that would be reason enough to make sure youre getting plenty of it in your diet. But theres much more to selenium than just being one of Es best friends.

In previous e-alerts Ive told you about studies that show how selenium helps reduce the risk of prostate, liver, colorectal and oesophageal cancers. In addition, selenium has superior antioxidant properties that may also help manage insulin levels.

Now a new UK study confirms research that reveals selenium to be an important factor in maintaining a strong immune system.

Granting immunity

The selenium content of grains, fruits and vegetables depends on the amount of selenium in the soil theyre grown in. Because the level of selenium in the soil throughout the UK is low, researchers at the University of Liverpool designed a study to examine the effect of selenium supplements on the immune system.

As reported in the current issue of the American Journal of Clinical Nutrition, the Liverpool team recruited 22 subjects who had low concentrations of plasma selenium. Over a period of 15 weeks, subjects received supplements of 50 micrograms (mcg) of selenium, 100 mcg of selenium, or a placebo.

Six weeks into the trial period, each subject was given an oral vaccine containing live attenuated poliomyelitis virus. By measuring certain systems that react to viruses (such as an increase of T cells and cytokines), researchers determined that immune response was significantly boosted in those subjects who received selenium supplements, compared to the placebo group. In addition, subjects who took selenium cleared the virus from their bodies faster than the placebo subjects.

In the conclusion to their study, the researchers state that even though supplements were effective in raising selenium to helpful levels - a daily supplement of more than 100 mcg may be necessary to provide optimal immune system response.

Highs and lows

As Ive mentioned in previous e-Alerts, selenium comes with a warning about overdoing intake of this nutrient. And while its true that mega-dosing might create problems, a toxic dose of selenium is actually hard to come by. 

Research into the cancer-preventive qualities of selenium indicates that a daily intake needs to be around 200 mcg to ensure adequate prevention. This is well over the RDA, of course, but you would have to get more than 2,500 mcg of selenium per day for an extended period to receive a toxic amount, so the chances of getting a dangerous dose are extremely slim. 

Besides fruit and vegetables, bread, fish, and meat all contain selenium. The real selenium powerhouse, however, is the Brazil nut, delivering more than 800 mcg of selenium per ounce. 

UK dilemma

Ive been sending you regular updates on the European Union Directive on Dietary Supplements, and have told you that many key nutrients will soon not be available in supplement doses sufficient to produce a therapeutic effect. So selenium presents a perfect example of how the EU directive could impact the health of European Union citizens.

According to NutraIngredients.com, the selenium content of UK soil is so low that the selenium levels in bread-making wheats are as much as 10 to 50 times lower than similar wheats in the US and Canada.

In other words, most UK citizens arent getting nearly enough selenium in their diets. For the time being, you have the option to supplement with as much selenium as you please. But in August 2005 the UK government will prohibit access to large doses of selenium.

This so-called protection will simply make it more difficult to help prevent cancer and improve immune defence.