Effects of Dietary Safflower Oil or Soybean Oil on the Milk Composition of the Maternal Rat, and Tissue Fatty Acid Composition and Learning Ability of Postnatal Rats.

This study was done to identify the effects of dietary safflower oil or soybean oil on the milk composition of maternal rats and the tissue fatty acid composition in postnatal rats. Different types of dietary fats affected the fatty acid pattern in the dam's milk. They affected tissue weight, lipid content, and phospholipid fatty acid compositions in the liver and brain of young rats, showing a large amount of docosahexaenoic acid in soybean oil-fed rats, and a large amount of docosapentaenoic acid in safflower oil-fed rats. The learning ability of the soybean oil-fed rats, evaluated by a swimming test, was significantly superior to that of the safflower oil-fed rats. The presence of large amounts of docosahexaenoic acid in the tissue phospholipid of soybean oil-fed neonatal rats without an alteration of their arachidonic acid levels may contribute to the enhancement of learning ability in rats.