This trace element is essential in the diet of humans and its deficiency may lead to various human disorders, including Keshan disease, a heart disorderaffecting primarily children in certain provinces of China, where the soil is deficient in selenium.

However, researchers Alexey Lobanov and Vadim Gladyshev have revealed that evolutionary changes have reduced the need for selenium, which occurs in proteins and is transported in blood plasma.

"Several trace elements are essential micronutrients for humans and animals but why some organisms use certain ones to a greater extent than others is not understood" said Gladyshev.

"We’ve found that the evolutionary change from fish to mammals was accompanied by a reduced use of proteins containing selenium," he added.

The evolved reduced need of selenium invites questions regarding the widely accepted use of supplements incorporating this trace element to maximize amounts of proteins that rely on it.

Supplements are taken without knowing which groups of the population canbenefit.

According to the researchers, only 20 pct of lower organisms use selenium-based proteins.

"The evolved reduced utilization of selenium-containing proteins in mammals raises important questions in human and animal nutrition, " he said.

"Selenoprotein expression is regulated such that people don’t need to rely so heavily on dietary selenium which is often present in excess amounts in the diet. Individuals should consider their age, sex and medical needs before taking such supplements on a regular basis," he added.

The study appears in open access journal Genome Biology.

Source-ANI
RAS/L