Dog Serum Lipid Responses to Dietary Fats Differing in the Chain Length of the Saturated Fatty Acids

Abstract

Fats of similar composition in terms of saturated, monoene, and polyene fatty acids, but differing in the chain length of the saturated fatty acids, were given alternately to groups of dogs at a level of 40% of the total calorie intake for periods of two weeks. Each experiment also included two control periods before and after the administration of the experimental fats, in which a low-fat diet containing 4% of fat calories was given. The glycerides of saturated fatty acids of 12- and 14-carbon atoms produced significantly higher serum cholesterol and phospholipid values than either the glycerides of 16- and 18-carbon saturated fatty acids or of 8- and 10-saturated fatty acids. When compared with the low-fat diet the experimental diets produced the following mean increases of serum cholesterol concentration (in mg per 100 ml ± SE of the mean): coconut oil, 146 ± 12.0; 12C mixture (60% of coconut oil, 40% of olive oil), 137 ± 9.9; 18C mixture (80% oleostock, 20% of totally hydrogenated corn oil), 76 ± 7.9; MCT mixture (a synthetic triglyceride containing mainly saturated fatty acids of 8- and 10-carbon atoms with 6% of olive oil and 2% of safflower oil), 21 ± 8.4. The serum phospholipid changes were parallel to those of cholesterol. The cholesterol levels produced by the glycerides of saturated fatty acids of 8- and 10-carbon atoms were similar to those produced in the dog by oils rich in polyunsaturated fatty acids (sunflower oil) given at the same proportion of the total calories.