Effects of dietary restriction on the composition of lipids in rat teeth

Abstract

The effect of food restriction on the quality and quantity of lipids in the teeth of rats was studied. Control animals were fed a nutritionally adequate diet ad libitum while test animals were restricted to 65 per cent as much diet day by day. Both groups were started on the regimen at weaning. Approximately half were sacrificed at 43 days of age. and the remainder at 78 days of age. Compared to control group, the rats fed the restricted diet gained less body weight and retained less lipids in teeth. The tooth lipids of test animals were predominantly phospholipids and cholesterol, while those of control animals were mostly triglycerides and phospholipids. Palmitic, stearic and oleic acids were the major fatty acids in the teeth of rats of both groups. The ratio of oleic acid to total fatty acids in teeth was higher in the test animals than in the control animals, and it increased sharply in the teeth of control animals as they advanced from 43 to 78 days of age. However, the fatty acid composition of tooth lipids of test animals did not change significantly during this period. Thus, food restriction can affect the lipid composition of the teeth of rats. The structural lipids (phospholipids and cholesterol) are retained while the storage lipids (triglycerides) are reduced.