Efficacy of a National Cholesterol Education Program Step 2 diet in normolipidemic and hypercholesterolemic middle-aged and elderly men and women

Abstract We tested the effects of a National Cholesterol Education Program (NCEP) Step 2 diet (30% of calories or less as total fat, less than 7% saturated fat, and less than 200 mg cholesterol per day) on plasma lipid levels in normocholesterolemic and hypercholesterolemic middle-aged and elderly men and women. Thirty-two subjects were studied. Eight normolipidemic subjects (6 men and 2 women, mean age 56±13 years) with LDL cholesterol levels of less than 4.14 mmol/L (160 mg/dL) were given a baseline diet similar in composition to the diet currently consumed in the United States (35% of calories as total fat and 14% as saturated fat, with 147 mg cholesterol per 1000 kcal) for 6 weeks. Subjects were then placed on an NCEP Step 2 diet (26% total fat, 4% saturated fat, 45 mg cholesterol per 1000 kcal) for 24 weeks. In addition, 24 subjects (12 men and 12 women, mean age 62±12 years) with moderate hypercholesterolemia (LDL cholesterol levels of 4.14 mmol/L or above) were given a baseline diet for 6 weeks and then the NCEP Step 2 diet for 6 weeks. Energy intakes were adjusted to keep body weight constant throughout the study. In both normolipidemic and hypercholesterolemic subjects, consumption of the NCEP Step 2 diet was associated with significant changes in levels of total cholesterol (−20% and −16%, respectively), LDL cholesterol (−21% and −18%, respectively), and HDL cholesterol (−16% and −15%, respectively). The plasma total cholesterol/HDL cholesterol ratio and plasma triglyceride, VLDL cholesterol, and lipoprotein(a) levels were not affected by the diet in either group. Similar responses were seen in men and women. The range of diet responsiveness in the 32 subjects was very large, with LDL cholesterol changes ranging from +5% to −40%. Thus, an NCEP Step 2 diet is effective in significantly reducing total and LDL cholesterol levels without changing the total cholesterol/HDL cholesterol ratio under controlled isoweight conditions in middle-aged and elderly normolipidemic and hypercholesterolemic men and women. The wide individual variation in diet responsiveness may indicate genetic variability.