Long-term effects of dietary monounsaturated and polyunsaturated fatty acids on plasma lipids in dogs

To compare the effect of monounsaturated vs. polyunsaturated fatty acids on plasma lipids, three months old dogs were studied for a period of six months. The dogs were fed a basal diet supplemented with either 14% olive oil or sunflower oil. Blood samples were taken fortnightly during this period. We have found changes in the various unsaturated fatty acids in response to the diet. Oleic and 20:3 n-9 acids were higher in the olive oil group while linoleic acid was increased in the dogs fed the sunflower oil diet. Arachidonic acid and PUFA n-3 > 18C index were nearly similar with both diets. The cholesterol levels were similar to those found in adult humans and no significant differences were brought about diets at any time. Thus a diet rich in monounsaturated fatty acids is as efficient as a polyunsaturated rich in relation to total cholesterol levels but more beneficial because of the antiatherogenic effect of HDL-cholesterol which is increased with this type of dietary fat.