Media Release

PhD researcher Graham Lyons with a wheat crop. Full Image (1.85M)

Tuesday, 16 December 2003

Wheat, a major Australian crop, may benefit our health even more when supplemented with selenium.

"Selenium is an essential micronutrient for human and animal health with antioxidant, anti-viral and anti-cancer effects," says Graham Lyons, a PhD student from the University of Adelaide's School of Agriculture and Wine.

Mr Lyons is investigating the importance of selenium in plant growth and development, and methods of increasing its concentration in wheat grain.

Levels of soil selenium vary in distribution and availability to plants on a world-wide scale. Selenium-deficient soils are widespread in Siberia and north-east to south central China, and in New Zealand. Prior to selenium fertilization of crops from 1984, soils in Finland were also deficient.

In Australia, areas at risk of selenium deficiency include the east coastal regions of Queensland and New South Wales, south west coast of Western Australia, Tasmania, South Australia's Mount Lofty Ranges and Kangaroo Island.

In regions where total soil selenium levels appear adequate, selenium may be unavailable to plants because of insoluble compounds forming between it and other soil components.

"Reduction in cancer prevention requires a supra-nutritional selenium intake, but in some regions selenium is declining in the food chain, and new strategies are required to increase its intake," Mr Lyons says.

To improve accumulation of selenium in plants, use of high selenium fertilizers, or a plant breeding approach could be utilized. Although application of fertilizer has been shown to improve soil selenium levels, breeding a high selenium wheat will facilitate retention of this trait, generation after generation. This self- sustainable approach is preferable to the continual purchase of selenium-containing fertilizers.

The overall benefits for consumers in Australia and overseas are potentially great, Mr Lyons says.

"Increasing the selenium content of wheat represents a food systems approach that would increase population intake, with consequent likely improvement in public health and health cost savings."