The findings reported by Fraser et al1 from the Adventist Health Study revive our interest in looking for data from prospective studies that show diet factors associated with favorable blood cholesterol or lipoprotein levels in free-living populations eventually lead to lower rates of coronary heart disease (CHD). Most of what we know about the effects of diet factors, particularly the saturation of fat and cholesterol, on serum lipid parameters derives from metabolic ward—type studies.2,3 Alas, such findings, within a cohort studied over time have been disappointing, indeed the findings have been contradictory. For example, in Framingham, Mass, the more saturated fat one ate, the more cholesterol one ate, the more calories one ate, the lower the person's serum cholesterol. The opposite of what one saw in the 26 metabolic ward studies, the opposite of what the equations provided by Hegsted et al2 and Keys et al3