August 2, 1950
Dr John Gofman created the original diet-heart and lipid hypothesis, but included carbohydrates as a factor driving cardiovascular disease.
Blood lipids and human atherosclerosis
Dr Tim Noakes:
In a previous column (3), I described how already in 1950, John Gofman, MD, had formulated the diet-heart and lipid hypotheses (4) two years before Keys would commandeer the ideas as his own.
Gofman posed as a double challenge for Keys and his future disciples. First, Gofman was far more qualified than Keys to undertake research into the dietary and other factors causing heart disease. But perhaps more importantly, Gofman’s diet-heart hypothesis gave equal weight to dietary fats and dietary carbohydrates as the factors driving atherosclerosis and the development of CHD.
According to Gofman:
What is solidly established is that the Sf° 20-400 lipoprotein levels [i.e., blood triglyceride or VLDL concentrations] on the average, can be raised by increasing the dietary carbohydrate intake and can be lowered by decreasing it. … Furthermore, many individuals who are characterized habitually by some type of error in their metabolism that makes their Sf° 20-400 lipoproteins habitually extremely high will experience a marked reduction in the blood levels of these lipoproteins when the carbohydrate intake is lowered. (5, p. 123, my addition)
These same lipoproteins are essentially unaffected, in the average case, by changing from animal to vegetable fats. This information is extremely crucial, for in many individuals the risk of coronary heart disease comes primarily from the Sf° 20-400 lipoproteins [VLDL or triglycerides]. For such individuals, any attempt to lower heart attack risk by shifting from animal fat to vegetable fat in the diet would be illogical. There would be no reason whatever to expect any benefits since one would be changing the diet in a manner directed toward affecting the Sf° 0-20 [LDL] lipoproteins, which is not the problem at hand for these persons. For such individuals, the preventive efforts would have to be directed toward lowering the carbohydrate intake, which will, on the average reduce the Sf° 20-400 lipoprotein levels. With respect to the effect of carbohydrates on the Sf° 20-400 lipoproteins, it is a matter of the amount of carbohydrate that is eaten rather than the total number of calories ingested. For example, if one maintains individuals at exactly the same number of calories per day, so that they do not alter the weight in any way, but takes out some of the carbohydrates in their diet and replaces them by vegetable oil, one finds that the Sf° 20-400 lipoprotein levels will fall. Achievement of this result of lowering the Sf° 20-400 lipoproteins requires neither any alteration in caloric intake nor any alteration in body weight. (5, p. 124, my additions and emphasis)
Subsequently, in 1958 Gofman pointed out a key logical flaw that has since been ignored (6). He noted that a number of studies had found increasing the dietary intake of vegetable oils produced a fall in blood cholesterol concentrations, and this has been interpreted as beneficial. But the addition of vegetable oils also reduced total carbohydrate intake, and since carbohydrate increases the Sf° 20-400 lipoprotein levels, which contain approximately 13% of cholesterol by weight, the shift from a higher- to a lower-carbohydrate diet might be the real reason why increasing the intake of vegetable oils causes a reduction in blood cholesterol concentrations.
Thus, Gofman warned: “No consideration was given by them to the possibility that the lowering of cholesterol levels might have been the result of the simultaneous removal of a large amount of carbohydrate from the diet” (6, p. 277).
Gofman next describes the effects of a low-carbohydrate (100 g/day) diet in a 65-year-old male subject with a previous myocardial infarction (Figure 2).
Figure 2: The effects of a low-carbohydrate diet in a myocardial infarction survivor. Note the low-carbohydrate diet produced a very large decrease in the Sf° 20-400 lipoprotein levels, now known as the VLDL-lipoproteins, which transport predominantly triglycerides. Total blood cholesterol concentration was unaffected by this dietary change. Despite this, the patient’s atherogenic index (AI) had fallen, placing him in a more favorable metabolic state according to Gofman’s understanding. Reproduced from data on Table V in reference 6, p. 279.
As Gofman wrote: “It can be seen from these data that a massive fall in the serum Sf° 20-400 lipoprotein levels occurs on the low-carbohydrate diet, without significant changes in the Sf° 0-20 lipoprotein levels. Accompanying this fall in lipoproteins is a highly marked and favourable reduction in the atherogenic index value” (6, p. 278-279).
Thus, the real originator of the diet-heart and lipid hypotheses stated that a low-carbohydrate, high-fat diet can be used in persons with established coronary atherosclerosis, presumably to reverse that disease.
These same principles of carbohydrate restriction have been applied successfully in several types of extreme derangement of lipoprotein level control of the Sf° 20-400 lipoprotein class, namely, in xanthoma tuberosum, essential hyperlipidemia, and in diabetes mellitus … . For such a [post-myocardial infarction] patient, it is quite clear that management of the problem of coronary disease by dietary means involves the use of a low-carbohydrate diet, and not a low-fat, high-carbohydrate diet which is so often prescribed when attention is not paid to the lipoprotein findings. (6, p. 279-280, my emphasis)
The importance of this is that this evidence anticipated Peter Kuo’s “discovery” of carbohydrate-sensitive hyper(tri)glyceridemia (7) and its reversal with a low-carbohydrate diet by nine years (Figures 6 and 7 in reference 8).
In his conclusions Gofman wrote:
The increase in risk of future myocardial infarction associated with elevation of lipoproteins of the Sf° 20-400 lipoprotein classes provides the basis for a rational application of dietary measures in this disease … . Dietary carbohydrate intake is a prime factor controlling the serum level of the Sf° 20-100 and Sf° 100-400 lipoprotein classes. Restriction of dietary carbohydrates can provoke marked falls in the serum level of these lipoproteins … . The serum cholesterol measurement can be a dangerously misleading guide in evaluation of the effect of diet upon the serum lipids … . Rational management of patients with coronary heart disease or of individuals attempting to avoid coronary disease depends upon knowledge of the lipoprotein distribution in the individual patient. (6, p. 282-283)
Elsewhere Gofman wrote: “Neglect of [the carbohydrate factor] can lead to rather serious consequences, first in the failure to correct the diet in some individuals who are very sensitive to the carbohydrate action; and second, by allowing certain individuals sensitive to the carbohydrate action to take too much carbohydrate as a replacement for some of their animal fats” (9, p. 156-157).
In one of his last publications, a 1960 editorial, he again emphasized his concern about the carbohydrate factor:
Several investigators have shown that a low-fat high-carbohydrate diet produces opposite trends in the blood cholesterol and the blood lipid levels. The cholesterol level falls because the low fat diet depresses the level of the cholesterol rich Sf° 0-20 lipoproteins. The triglyceride level rises because the high carbohydrate intake elevates the level of the triglyceride-rich Sf° 20-400 lipoproteins. Both the triglyceride-bearing and cholesterol-bearing lipoproteins have been associated with the development of coronary disease. It therefore behoves the physician utilizing the dietary approach to understand the likelihood that a focus on the fat intake without an appreciation of the effect of carbohydrate intake will not lower all the blood lipids associated with the development of coronary heart disease. (10, p. 83)