Cholesterol-lowering diets. A review of the evidence

To evaluate the efficacy of the high-risk approach and the population approach for cholesterol lowering, large trials of dietary intervention (n > or = 150) and smaller trials of angiographic assessment of the impact of diet on coronary disease were reviewed. Two trials of dietary therapy as intensive individualized counseling in individuals at usual risk for coronary disease achieved 75% to 80% of the cholesterol lowering predicted by metabolic ward studies and produced a 5% to 14% reduction in total cholesterol levels. Four studies in high-risk individuals exceeded predictions and achieved a 4% to 17% reduction in total cholesterol levels. Similar efficacy was observed in six of the seven trials of diet for secondary prevention. Four trials employing the population approach achieved smaller but often significant reductions in total cholesterol levels of 1% to 11%. No tachyphylaxis to dietary therapy occurred in trials in which dietary counseling was maintained during the trial. The effectiveness of diet is enhanced when individualized counseling is used, follow-up is maintained, and weight reduction is achieved.