Soy consumption decreased total cholesterol by approximately 10%, low-density lipoprotein cholesterol by 13%, and triglycer-ides by 10% and increased high-density lipoprotein cholesterol by approximately 2.5% in clinical trials of participants consuming soy compared with another protein (usually casein). These effects were even greater in hypercholes-terolemic individuals. Although the mechanism for the improvement in lipid profile is not completely understood, the most likely explanation is that these effects are mediated by isoflavones contained in the soy. The beneficial effects on lipid and lipoprotein profile can be achieved with the addition of a single serving of dietary soy each day. Increased soy intake fits well into the recommendations of the National Cholesterol Education Program, which suggest dietary changes and exercise as initial treatment prior to initiating pharmacologic therapy. Increased intake of soy protein in patients with borderline or high-normal hypercholesterolemia seems well warranted and may reduce the need for subsequent pharmacologic treatment.