Test period for the study of hypocholesterolemic effect of test material in rats.

Rats were made hypercholesterolaemic by giving them a diet with tallow or vanaspati (partly hydrogenated vegetable oils), cholesterol and bile salts. Then part or all of the tallow or vanaspati was replaced by walnut kernel or cold-pressed unrefined walnut oil. Growth during 8 weeks was normal and did not differ among groups. During the first 4 weeks on walnut fats, serum cholesterol decreased from 230 to 125 mg/100 ml. There was no further decrease during the next 4 weeks.