Effects of sucrose and cornstarch on the development of copper deficiency in rats fed high levels of zinc

Abstract

The effects of dietary carbohydrate and zinc on the development of copper deficiency were investigated. Male Sprague-Dawley rats (n=48) were fed one of eight diets in a 2×2×2 factorial design for 21 days. Two levels of copper (0.94 or 10 μg/g diet) and zinc (22 or 197 μg/g diet), and two types of carbohydrate (sucrose or cornstarch, 62% of the diet) were fed. Compared to copper-adequate rats, copper-deficient rats had lower hematocrit, hemoglobin, ceruloplasmin, and tissue copper levels, and higher hepatic iron levels. Sucrose and high dietary zinc promoted the development of copper deficiency. Copper-deficient rats fed 197 μg Zn/g diet with sucrose had significantly lower hematocrit and hemoglobin levels, hepatic copper levels, and tibia iron levels compared to all other copper-deficient rats. In copper-deficient rats, high dietary zinc significantly decreased copper and iron absorption, tibia iron levels, and hepatic iron accumulation. It appears that sucrose and high dietary zinc alter the development of copper deficiency through changes in both copper and iron metabolism.