*Christopher Gardner et al. “The Effect of a Plant-Based Diet on Plasma Lipids in Hypercholesterolemic Adults,” Annals of Internal Medicine, 2005; 142: 725–33. Other similar trials have found striking protective effects in more traditional, plant-based dietary patterns that no single nutrient can adequately explain. In the D.A.S.H. (Dietary Approaches to Stop Hypertension) study, a diet rich in fruits and vegetables and low in saturated fat reduced blood pressure even when salt intake and weight remained unchanged. (Lawrence J. Appel, et al., “A Clinical Trial of the Effects of Dietary Patterns on Blood Pressure,” New England Journal of Medicine, Vol. 336, No. 16, April 17, 1997.) Neither of these studies relied on food-frequency questionnaires; rather, the researchers prepared the meals for the participants. The Lyon Diet Heart Study found that the Mediterranean diet, when compared to a Western diet, offered protection against a second heart attack during the four years patients were followed. (Michel de Lorgeril et al., “Mediterranean Diet, Traditional Risk Factors, and the Rate of Cardiovascular Complications after Myocardial Infarction,” Circulation, 1999:99; 779–85.)