SERUM-LIPIDS AND LIPOPROTEINS FROM RATS FED DIFFERENT DIETARY OILS

The effects of several dietary oils, rich in monounsaturated fatty aci ds (MUFA), (n-6) or (n-3) polyunsaturated fatty acids (PUFA) on concen trations of cholesterol, triglycerides and phospholipids in serum and lipoproteins were investigated in rats. Male Sprague-Dawley rats were first maintained on a diet based predominantly on coconut oil for 28 d ays then for another 20 days on one of the semipurified test diets, co ntaining 5 g/100 g olive oil, safflower oil, evening primrose oil, lin seed oil or salmon oil at the expense of coconut oil. Oils rich in (n- 3) PUFA had a more pronounced lowering effect on serum lipids than oil s rich in (n-6) PUFA or MUFA. The most striking effects of the dietary oils were observed on cholesterol and phospholipid concentrations in VLDL and HDL as well as VLDL triglycerides. The hypocholesterolemic ef fect of salmon oil rich in long-chain (n-3) PUFA was more intensive th an that of linseed oil rich in alpha-linolenic acid. Olive oil contain ing MUFA had no effect on lipids in serum and lipoproteins. Safflower oil and evening primrose oils rich in (n-6) PUFA had only slight effec ts on serum lipids compared to coconut oil.