EFFECTS OF SATURATED FAT IN RATS FED RAPESEED OIL

Abstract

The effects of increasing the saturated fatty acids in a dietary vegetable oil composed mostly of unsaturated fatty acids were studied in rats. A mixture of palm oil and Swedish rapeseed oil fed for 4 weeks as 20% of a purified diet promoted weight gains which exceeded those obtained with Polish rapeseed oil of a similar content of erucic acid, and altered the proportion of saturated fatty acids in the tissues to reflect that of the diet. When methyl esters of saturated fatty acids were added to Swedish rapeseed oil, similar effects on weight gain were not observed, but methyl esters of fatty acids from corn oil and rapeseed oil were shown to be of less nutritional value than the original glycerides. From fatty acids of olive oil, glycerides containing 3% palmitic acid were prepared, and produced weight gains which did not differ significantly from those of rats fed Polish rapeseed oil with a similar content of palmitic acid and 20% erucic acid. The characteristic effects of rapeseed oil are, therefore, attributed to its low content of saturated fatty acids as well as its high content of erucic acid.