A clinical study of the effects of a carbohydrate restricted diet on serum cholesterol levels in a randomly selected group of adult human male subjects

By the middle of the twentieth century, cardiovascular diseases accounted for over fifty per cent of all deaths in the United States, and, in spite of extensive and accelerated probing into their etiology, little of a practical nature, prophylactically or therapeutically, had been deduced. Those devices that had been regarded as technically and professionally acceptable were nevertheless unnatural and sometimes bizarre. But because of their presumed efficacy, limited though it was, and the absence of more practicable means at the time, they were employed with conservatism, misgivings, and, sometimes, temerity. General agreement existed among research scientists in the field that some obscure factor, or factors, in the eating habits and food patterns of the population was the primary responsible agent. Accordingly, foods previously regarded as nutritionally valuable were impugned. Conceivably, dietary deficiencies could arise as an ultimate consequence of such deprivation. Hypercholesterolemia, purported to be associated with Western affluence, while assailed by many investigators as a direct causative influence in the evolution of atheromatosis, the sine qua non, was considered equivocal with respect to its affinity or relationship in this respect. Varied mechanisms and methods for lowering or ameliorating serum cholesterol levels involved intervention somewhere in the biosynthetic peregrinations of the cholesterol constituent complex. Whatever this latter process might have revealed was at the time obscure and minimally comprehensible with respect to any significant role it might assume in this enigmatic malady. For many years, it had also become patent, according to Dr. David Kritchevsky, "that the serum cholesterol level per se was far from infallible as a predictor of heart disease." Assays exploring the carbohydrate factor of the diet had been few, and his was particularly true with reference to studies on human subjects. The urgency and seriousness of the problem, and the paucity of available practical Information on the effect of dietary carbohydrate, made an investigation of this nature mandatory. A group of presumably healthy adult men, all Caucasian, and ethnically similar, working in essentially sedentary occupations, and representing a relatively wide range of social, cultural, professional, vocational and educational levels, was selected. Preliminary serial blood serum cholesterol determinations were performed on each one for a period of ten consecutive weeks, and data recorded. During this phase, they were following their usual diet practices. This was followed by a period of 4 weeks' testing and observance of a dietary regimen with carbohydrate restricted to 100+- grams. All other features of the diet were allowed to remain essentially as they had been, except that the participants were instructed to ingest cholesterol-rich foods liberally, as well as saturated fats. Comparisons of the mean cholesterol values, as well as the maximal levels found, on each subject were made between the preliminary period and the diet phase.[...]