EFFECT ON SERUM-LIPIDS OF ADDITION OF SAFFLOWER OIL OR OLIVE OIL TO VERY-LOW-FAT DIETS RICH IN LEAN BEEF

The cholesterol-lowering effect of very-low-fat diets rich in lean bee f has previously been shown to be reversed with the addition of beef f at. The aim Of this study was to determine the effect on serum lipid l evels of the addition of safflower oil or olive oil to a very-low-fat diet rich in lean beef. Subjects were assigned to either the safflower oil or the olive oil group. In the first week the subjects ate their usual diet; in the second and third weeks all subjects ate a very-low- fat (9% of energy) diet rich in lean beef. hi the fourth and fifth wee ks the fat content of the diet was increased in a stepwise fashion to 20% and 30% of energy, respectively, by substituting safflower oil or olive oil for carbohydrate. Low-density lipoprotein cholesterol (LDL-C ) concentrations decreased by 13% to 14%, and high-density lipoprotein cholesterol (HDL-C) concentrations decreased by 20% to 25% in subject s after 2 weeks of the very-low-fat, lean-beef diet. The LDL-C concent rations remained low after the addition of safflower oil or olive oil to the very-low-fat diet. These results indicate that a reduction in s aturated fat, not total fat, is required to reduce serum total cholest erol and LDL-C levels. Provided that the total diet is low in saturate d fat, these serum lipid responses can be achieved even when the diet is rich in fat-trimmed lean beef.