New trading patterns blamed for selenium intake decline

The UKs dietary needs are not being met as a result of the change in our trading patterns since joining the EU, according to new research from the University of Surrey.

The scientists contend that a change to wheat low in selenium could have negative health consequences.

Before joining the EU, the UK used to buy the majority of its wheat from Canada and the USA. North America has soil, which is naturally rich in selenium, an essential mineral known to have vital cancer prevention properties.

But European selenium levels have been falling since the EU imposed levies on wheat imports from the US. The UK now uses homegrown and EU wheat, which the scientists say has a lower selenium content.

As a result, average intake of selenium in the UK has fallen from 60 to 34 micrograms per day. The European recommended daily intake (RDI) is 65 micrograms.

Since as early as the 1960s, geographical studies by Shamberger and Frost in 1969, Schrauzer in 1977 and Clark in 1991, have shown a consistent trend for populations with low selenium intakes to have higher cancer mortality rates.

And a study carried out in France by Akbaraly et al last year, which followed a group of 1,389 elderly volunteers to for a period of nine years, found that those with low selenium diets were considerably more likely to die from cancer than those with high selenium diets.

Selenium intake has also been linked to protecting the immune system. Researchers from the University of North Carolina, and the US Department of Agriculture reported that selenium deficient mice infected with a mild strain of influenza developed severe lung infections. When the researchers recovered the virus from the mice, they found an increased number of viral mutations, resulting in a more virulent phenotype. (Trends in Microbiology, 2004, Vol. 12, pp. 417-423).

Most recently, increasing the daily intake of selenium could cut the risk of bladder cancer by 70 per cent, according to a new study from Belgium.

Continued coverage of positive results, like the new study published in the International Journal of Urology (Vol. 13, pp. 1180-1184), could help further increase public awareness of a mineral already associated with reducing the risk of prostate and lung cancer, as well as boosting the immune system.

But despite the wealth of research backing up selenium's health benefits, consumer awareness remains low.

"It is in the public interest to finance more research on the apparent relationship between selenium and cancer risk, said Dr Margaret Rayman of the division of nutrition, dietetics and food science from the School of Biomedical and Molecular Sciences in the University of Surrey.

World wheat supply is forecast to tighten in 2006/07 as production falls for the second consecutive year. Production in Russia, Ukraine, and Eastern Europe is projected to be down sharply as a very dry fall reduced plantings, and harsh weather has adversely impacted yields.

US wheat imports into the EU remain constrained by tight tariffs.

The Surrey scientists say that one way of ensuring that consumers consume an adequate amount of selenium would be for consumers to eat a few Brazil nuts a day. Dr Rayman has also been involved in the development of functional foods with a higher selenium content that can be readily absorbed by the body.