Long-term Studies on the Hypolipemic Effect of Dietary Calcium in Mature Male Rats Fed Cocoa Butter

Abstract

To determine whether the hypolipemic action of elevated dietary calcium previously noted in a 3-week experiment was a transient or a persistent effect, 32 mature male Holtzman-strain albino rats were divided into 5 groups, one being fed commercial rat pellets with 5% fat and 1.15% calcium, and the others a cornsoya ration containing 18% added cocoa butter and 2% added cholesterol for 5 months. Dietary calcium was varied at 0.08, 0.2, 1.2 and 2% of diet. Serum total lipids, phospholipids, cholesterol and triglycerides decreased significantly with increasing dietary calcium, often to levels equal to or below those of the control diet. Liver, heart and aortic lipids were unaffected. Fecal lipids increased significantly between the 0.2% and 1.2% calcium level, primarily because of an increase in the free fatty acids. Fecal bile acids rose significantly at the 0.2% calcium level, with no further increase on increased calcium. 3-β-Hydroxysterol excretion increased as calcium increased and was, at the higher calcium levels, found to equal all the exogenous cholesterol, whereas fecal lipid excretion was found to account for the weight gain differences between the various calcium levels. Histological examination of the kidneys indicated no pathological condition attributable to high dietary calcium.