EFFECT OF LONG-TERM FEEDING OF PALM OIL ON GROWTH AND LIPID-METABOLISM IN RATS

The effect of palm oil on the lipid metabolism of rats was studied in an eighteen week-long experiment in rats. Four groups of male rats of Wistar strain (10 each) were fed ad lib for 18 weeks on diets containing casein, starch, vitamins and minerals to which oils were incorporated at 5% and 20% levels. Rats fed on peanut oil were used as controls. 20% oil-fed groups gained more weight than 5% oil-fed groups. However, the liver cholesterol values in 20% peanut oil-fed groups were lower when calculated in relation to liver weight. Triglycerides were higher in 20% oil-fed groups. Analysis of liver and plasma fatty acids indicated that palm oil-fed groups had a higher content of saturated fatty acids such as palmitic, stearic and monounsaturated fatty acids (oleic, palmitoleic) and low levels of linoleic acid. The oleic/linoleic acid ratio in the plasma and liver correlated with the types of fat consumed whereas the P/S ratios, although were the same in the plasma, indicated th storage of linoleic acid (18:2 n6) in the liver. Thus, our studies indicate long term feeding of palm oil does not have any adverse effect in rats.