Current status of the cholesterol controversy.

It has been established that elevated levels of serum cholesterol, particularly of the low-density lipoprotein fraction, are associated with increased risk of myocardial infarction. There is no doubt that both low-density lipoprotein cholesterol levels and total plasma cholesterol levels can be lowered by diet and/or by drug therapy in almost all patients. The true controversy lies in whether intervention is associated with an actual reduction in the incidence of myocardial infarction. A great deal of circumstantial evidence suggests a positive correlation, but to date this can not yet be supported by direct data from clinical trials performed in man. It is, therefore, not certain whether a lowering of the serum cholesterol level results in a simultaneous reduction of risk.