Increasing human intake of selenium by supplementing food animals with organic selenium

Abstract

The concentration of global crop and food animal production in regions where plant selenium content is low has led to a decline in the amount of selenium in the human food supply. The central reason is that where soil pH is acidic, selenium cannot be absorbed by plants, thereby preventing transfer of selenoamino acids up the food chain through cereal grains and food animal products. Direct addition of inorganic selenium salts prevents acute deficiency symptoms, however selenium salts added to food animal diets do not provide meaningful amounts of selenium in edible animal tissues. Because human selenium status is a public health concern, researchers have examined nutritional means of increasing the selenium content of meat, milk and eggs using selenium produced by yeast, which like higher plants are able to form selenoamino acids. While part of the focus is on producing ‘designer’ foods, a more general question pertains to both existing selenium levels in food animal products and to those when commercial food animals are given selenium in naturally-occurring organic vs inorganic form. The following summarizes selenium levels in edible tissues in commercial and controlled research settings where inorganic and organic (Sel-PlexTM selenium yeast, Alltech Inc.) were compared.