BBC - Sunday, 29 April, 2001, 22:59 GMT 23:59 UK

Mineral key to flu suffering

Could a deficiency prolong the misery of flu? Diets low in the mineral selenium may mean people suffer more when they contract flu, research suggests.

Researchers found the influenza virus caused more damage in mice lacking selenium than in their selenium-rich counterparts.

Those missing the mineral were more prone to harmful lung inflammation, which also lasted considerably longer.

Good sources of selenium include wheat, rice and meat, so an average "healthy" diet, as well as a balanced vegan or vegetarian diet should contain good amounts.

The report appeared in the Federation of American Societies for Experimental Biology journal.

Author Dr Melinda Beck said: "It's been known for a long time that if you're malnourished, you're more susceptible to infectious diseases, and so it's not really remarkable that the mice would be sicker when they have a deficiency.

"We looked at specific elements of the mice's immune systems that were associated with the increase in pathology and found certain changes.

Essential nutrients

"What that suggests is that the deficiency in selenium altered their immune response, and so they got sicker than they would normally.

"This shows you need to have a balance in all the essential nutrients, and that a deficiency in just one can have a profound effect."

Selenium is a known anti-oxidant - a mineral which helps reduce the number of potentially damaging and inflammatory "free radical" molecules circulating in the body.

Selenium has been touted as a possible protective vitamin against certain forms of cancer and trials are underway to test this.

Other research suggests that it plays a key role in male fertility.

But US health officials are keen that people should not overdose on large supplements of selenium or the major vitamins, advising a maximum daily dose of 400 micrograms.

-- Anonymous, April 30, 2001