Effects of dietary galactose and fructose on rats fed diets marginal or adequate in copper for 9-21 months

This study was designed to monitor the metabolic differences after feeding starch, galactose and fructose diets with adequate or marginal copper level s to normal male rats over a period of 9-21 months. Two hundred and forty-f ive weanling male Sprague-Dawley rats weighing approximately 50 -60 g were randomly divided into one of the eight dietary groups. All diets were eithe r Cu marginal (1.5 mug/g diet) or adequate (5-6 mug/g) with 627 carbohydrat e (g/kg diet) as starch; 500 galactose and 127 starch; 500 fructose and 127 starch; or 400 galactose and 227 fructose. Glycated hemoglobin, ceruloplas min oxidase activity, hematocrit, and plasma glucose, cholesterol, and trig lyceride were measured in 72 rats after nine months. Galactose-fed rats had the lowest (P < 0.0001) body weights. Severe mortality rates were found in galactose-fructose-marginal Cu-fed rats. Marginal Cu deficiency significan tly (P < 0.0001) reduced hepatic copper and increased hepatic Fe in all car bohydrate groups. Ceruloplasmin activity of the rats fed the marginal Cu an d fructose-containing diets declined to undetectable levels and plasma chol esterol levels increased. Glycated hemoglobin was significantly (P <less th an> 0.001) increased in the galactose-fed rats compared to fructose or star ch-fed rats regardless of dietary copper concentration. The data suggest th at dietary galactose and fructose exacerbate effects of long term marginal Cu intake including hypertrophy of liver, heart and kidney, hyperlipidemia, and increased mortality. (C) 2001 Elsevier Science Inc. All rights reserve d.