This paper describes early INCAP studies showing that cholesterol and lipoprotein levels were much lower in the low-income populations of Central America than values that were just beginning to emerge from industrialized countries. These led to the collection of aortas and coronary vessels from 14,610 males and 7,906 females from serial autopsies from 12 public general hospitals in developing countries, mostly in Latin America and in New Orleans and Oslo. The severity of atherosclerotic lesions in the samples was evaluated independently by four pathologists after the samples were randomized, who determined that the severity of atherosclerosis progressed so slowly in the developing country samples that it rarely became clinically significant. The strongest correlation with the severity of lesions was the fat content of the diet.
