Self-selection of copper-containing diets by copper-deficient and overloaded rats

To determine the effect of copper status on the preference for copper-containing food, male Sprague-Dawley rats were weaned to a copper-deficient, copper-adequate or high-copper diet. Four weeks later, alterations in copper status were confirmed by measurement of liver copper concentrations. Rats (n=10) were then given the choice between a copper-adequate or a copper-restricted diet of similar composition. Preference scores indicated that control rats preferred copper-deficient food. Preferences of rats on the high-copper diet were not different from control rats, suggesting that copper overload did not alter the pattern of selection. However, 7 of the 10 copper-deficient rats ate 80% or more of their intake as copper-adequate food resulting in preference scores that were significantly different from controls (p<0.03). This alteration in preference was corrected within 1 day of access to copper-adequate food.