Cola beverage consumption induces bone mineralization reduction in ovariectomized rats

Background A significant association of cola beverage consumption and incre ased risk of bone fractures has been recently reported. The present study w as carried out to examine the relationship of cola soft drink intake and bo ne mineral density in ovariectomized rats. Methods. Study 1. Four groups of 10 female Sprague-Dawley rats were studied . Animals from groups II, III, and IV were bilaterally ovariectomized. Anim als from groups I and II received tap water for drinking, while animals fro m groups III and IV each drank a different commercial brand of cola soft dr ink. After 2 months on these diets, the following were measured: solid diet and liquid consumption; bone mineral density; calcium in bone ashes; femor al cortex width; calcium; phosphate: albumin; creatinine; alkaline phosphat ase; 25-OH hydroxyvitamin D, and PTH. Study 2, Two groups of seven ovariect omized rats were compared. Group A animals received the same management as the group III animals from study 1 (cola soft drink and rat chow ad libitum ), while rats from group B received tap water for drinking and pair-feeding . After 2 months plasmatic ionized calcium, phosphate, creatinine, albumin, calcium in femoral ashes, and femoral cortex width were measured. Results. Study 1. Rats consuming cola beverages(groups III and IV) had a th reefold higher liquid intake than rats consuming water (groups I and II). D aily solid food intake of rats consuming cola soft drinks was one-half that of rats consuming water. Ruts consuming soft drinks developed hypocalcemia and their femoral mineral density measured by DEXA was significantly lower than control animals as follows: group I, 0.20 +/- 0.02; group II, 0.18 +/ - 0.01; group III, 0.16 +/- 0.01, and group IV; 0.16 0.01 g/cm(2). Study 2. To rule out the possibility that these calcium and bone mineral disorders were caused by decreased solid food intake, a pair-fed group was studied. D espite a lower body weight, pair-fed animals consuming tap water did not de velop bone mineral reduction or hypocalcemia. Conclusions. These data suggest that heavy intake of cola soft drinks has t he potential of reducing femoral mineral density. (C) 2000 IMSS, Published by Elsevier Science Inc.