Effect of a dietary oxidized fat on the selenium status of rats

The present study was undertaken to investigate whether the selenium status of rats is affected by a dietary thermally oxidized fat. An experiment was carried out which included 4 groups of rats fed diets with fresh fat or oxidized fat, heated at a temperature of 55degreesC, containing either 70 or 570 mug selenium per kg, over a period of 56 days. Selenium concentrations in liver and plasma and the activity of glutathione peroxidase in plasma (pGPx) were measured to assess the selenium status of the rats. Rats fed the diets containing 570 mug selenium per kg, had significantly higher selenium concentrations in liver and plasma and a higher activity of pGPx than rats fed the diet containing 70 mug selenium per kg. In the rats fed the diet containing 70 mug selenium per kg, feeding the oxidized fat significantly reduced the concentrations of selenium in liver and plasma and the activity of pGPx compared with feeding the fresh fat. In the rats fed the diets containing 570 mug selenium per kg, feeding the oxidized fat, reduced the selenium concentration and the activity of pGPx, whereas the concentration of selenium in the liver remained unchanged compared with fresh fat. The study, in conclusion, shows that feeding an oxidized fat reduces the selenium status in rats, particularly at low selenium supply.