INFLUENCE OF FLAXSEED ON SERUM AND LIVER LIPIDS IN RATS

Rats were fed varying levels of flaxseed for three weeks. The diets were designed to provide 10%, 15%, and 20% flaxseed oil, respectively. The diets also contained 0.5% cholesterol and 0.2% cholic acid. Liver weight increased with increasing levels of fat. Serum cholesterol levels rose with increasing levels of fat, but HDL cholesterol and triglycerides were unaffected. Considering the presence of both cholesterol and cholic acid in the diet, the elevations of serum cholesterol were modest, which may reflect a potent hypocholesterolemic effect of linolenic acid. Liver total cholesterol levels fell with increasing levels of dietary flaxseed. Liver cholesteryl ester levels (%) were lower in rats fed higher doses of flaxseed, indicating reduced cholesterol deposition. Liver triglyceride levels were the same in all three dietary groups. Calculations of the serum plus liver cholesterol pool showed them to be 334 mg, 273 mg, and 252 mg for rats fed 10%, 15%, or 20% flaxseed oil, respectively. Since high levels of flaxseed reduced cholesterol deposition in liver, it might be useful to test in experimental atherosclerosis.