Effects of cocoa upon the growth of weanling male Sprague-Dawley rats fed fluid whole milk diets

Extract: Four groups of 12 male Sprague-Dawley rats were treated with fluid milk (diet 1), fluid milk and 1.22% cocoa (diet 2-average amount of cocoa present in commercially available chocolate milk), fluid milk and 2.44% cocoa (diet 3), or fluid milk and 3.66% cocoa (diet 4) diets. By the termination of the four week experiment, the mean final body weights of rats fed diet 1 or diet 2 were significantly greater than from the group fed diet 3. The rats which consumed diets 1,2,or 3 had significantly greater mean final body weights than the rats which consumed diet 4. The reduced mean final body weight of rats treated with diet 4 could be attributed to the significant reduction of food intake when compared with the other groups. The mean white blood cell count of rats treated with diet 4 was significantly reduced compared with the other treatment groups. This could have been the result of the significantly reduced diet consumption by the diet 4 treated group of rats. The groups of rats treated with diets 2,3, or 4 (containing cocoa) had significantly larger mean red blood cell counts, mean hemoglobin content, and mean hematocrit values than did rats fed diet 1 (control). These significantly elevated hematology parameters could potentially enhance the oxygen carrying capacity of the blood and enable the animals to perform greater muscular activity prior to fatigue. The mean plasma calcium concentrations from rats fed diets 1,2,or 3 were significantly larger than from the group treated with diet 4. The addition of 1.22% cocoa to a fluid milk diet did not have a negative effect on any of the biological parameters measured. In fact, the addition of cocoa to a fluid milk diet had a beneficial effect upon many of the hematology parameters measured. This data further substantiates the nutritional benefit of the consumption of chocolate milk. (author)