A few years back, Denise Minger instantly rose to fame in the Low-Carb and Paleo diet circles shortly after publishing a blog post criticizing the chapter describing the findings from the China-Cornell-Oxford Project in the book, The China Study, written by Dr. T. Colin Campbell.1This blog post was very welcomed by proponents of these diets as it provided them with a reference which they used to attempt to use refute much criticism they had been receiving for promoting a diet rich in animal foods.
As described previously byPlant Positive, andmyself, there were a number of serious concerns with Minger’s interpretations of the data from the China Study which further casted doubt on her true intentions. One particular example was Minger’s attempt to attribute the association between fat intake, a marker of animal food intake, and an increased risk of breast cancer mortality in the China Study to the consumption of “hormone-injected livestock“.3The fact that the mortality data that Minger examined was from the early to mid-1970s, a time when the use of hormone injections was not exactly widely practiced throughout rural China casts serious doubt on this claim. Furthermore, it is important to consider that the time lag between exposure to a causal agent and when breast cancer becomes life threatening is more than often several decades. For example, the greatest risk of excess death from radiation-related solid cancers, such as breast cancer among the atomic bomb survivors of Hiroshima and Nagasaki was more than half a century after exposure.4It is therefore likely that most of the dietary related deaths from breast cancer that occurred in the early 1970s would more likely to have been caused by the diets consumed several decades earlier, likely even beforehormone injections was used to any meaningful extent in China. This provides further suggestive evidence that Minger was merely trying to downplay the evidence of the harms of animal foods, rather than producing an honest review.
The IMPACT of the Food Pyramid
|The original USDA Food Pyramid from 1992|
The title Death By Food Pyramid that Denise Minger and/or publisher chose for this book provides readers with the false impression that Americans (and people in other nations which share similar dietary guidelines) are complying with the federal guidelines, and, as a result more are dying prematurely of dietary related diseases. Evidence strongly casts doubt on such suggestions. For example, despite the tendency for people to over-report the intake of healthy food in food surveys, such surveys have nevertheless found that nearly the entire population of the United States does not adhere to the federal dietary recommendations.5
Although it may be fair to suggest that the federal dietary guidelines can be considered as a lost opportunity to save additional lives, evidence does not suggest that the Food Pyramid promoted a diet that would have increased the risk of dietary related deaths compared to the cholesterol-rich diet consumed by Americans in earlier decades. For example, numerous studies have found that in a number of nations, including the United States, large reductions in serum cholesterol, largely as the result of displacing the proportion of saturated fat in the diet with other sources of energy can explain a significant portion of the decline in coronary heart disease mortality. These large declines generally occurred in order of the nations that were earlier to embrace the lipid hypothesis and reduce the intake of animal fat. For example, this decline began in the late 1960s in the United States, Finland, Australia and New Zealand, but not until a decade later in the United Kingdom which had been distracted by John Yudkin’s sugar hypothesis and much slower to embrace the lipid hypothesis.6 In the former communist nations of Eastern Europe, this decline did not occur until the 1990s, following the abolishment of communist subsidies on meat and animal fats after the collapse of the Soviet Union.6
Although Minger notes this observed decline in mortality in the United States in her book, she suggests that it can more likely be explained by the reduction in smoking prevalence, rather than the displacement of saturated fat with other sources of energy, such as omega-6 polyunsaturated fats and carbohydrate. Minger however failed to provide any data demonstrating what portion of the decline in mortality could be attributed to changes in smoking prevalence and diet/serum lipids. The IMPACT CHD mortality model incorporates among the highest quality data available for risk factors and treatments to help determine how individual risk factors and treatments have contributed to changes in coronary heart disease mortality of a given population. The fact that the prediction of change in coronary heart disease mortality calculated by the IMPACT model has been demonstrated to be largely comparable with the actual change in mortality in nations throughout North America, Northern, Southern, Eastern and Western Europe, South-East Asia, Africa, Australasia and the Middle East provides confidence in the validity of this model.789101112131415161718192021
It should be noted that the use of the IMPACT model has made it clear that in those nations which experienced the most dramatic declines in heart disease mortality in the world, such as Finland and the former communist nations of Eastern Europe, large dietary induced declines in serum cholesterol has typically explained a very significant portion of the decline.8 9 10 2223The same can be said for the increases in serum cholesterol as the result of an increase in intake of cholesterol and saturated fat, and the surge in heart disease mortality among a number of populations, such as Beijing.17 19 These findings are also supported by earlier studies.6 For example, in 1989 Epstein examined the changes in coronary heart disease mortality in 27 countries during the previous 10 to 25 years, noting that:24
In almost all of the countries with major falls or rises in CHD mortality, there are, respectively, corresponding decreases or increases in animal fat consumption…
The IMPACT model found that in the United States between the years of 1980 and 2000, a time at which coronary heart disease mortality was reduced by about half, the decline in serum cholesterol, largely due to changes in diet, could explain approximately 24% of this reduction, compared to only about 12% for the decline in smoking prevalence (Fig. 1).722Considering that coronary heart disease has been the leading cause of death in the United States, as well as many other nations for the best part of a century, if anything, a more appropriate title for Minger’s book would be “Saved By Food Pyramid“.25
Worst Case Scenario for the McGovern Report: Denise Minger
In an attempt to criticize the science supporting the McGovern Report, Minger focuses on a publication from the American Society for Clinical Nutrition (ASCN) expert committee, published in the American Journal of Clinical Nutrition in 1979, which critically examined the evidence for each of the foods and nutrients that the McGovern Report recommended limiting. Minger states that there was significant disagreement among the ASCN panel regarding the causal association between dietary cholesterol, saturated fat and heart disease. Nevertheless, the panel gave the strength of evidence of a causal association for dietary cholesterol and saturated fat combined a score of 73 out of 100, which was considered “rather high”. Because the score of each of the panelists contributed equally to the overall score, this rather high score suggests that very few of the panelists were in significant disagreement with the diet-heart hypothesis. For dietary cholesterol and saturated fat considered separately, the scores were a little lower, which was suggested to be due to the nature of these two nutrients being highly correlated, making it difficult to determine which contributes more to atherosclerotic heart disease.26 In comparison, virtually all of the panelists considered the evidence linking carbohydrate (ie. sugar) to heart disease as being “extremely weak”, scoring it only 11 out of 100.26 This fact is however largely neglected by Minger despite discussing the potential adverse effects of sugar on heart health in this book.
These failures could have been due to the short duration of the studies, the age of subjects at inception of the studies, or to the inadequacy of the changes in plasma lipids so produced.
Animal studies, particularly in subhuman primates, reveal an unequivocal causal relation between dietary cholesterol or saturated fat, plasma cholesterol levels and development or regression of atherosclerosis
…there is every reason to conclude-based on all seven criterias set forth-that the epidemiologic associations among dietary lipids serum cholesterol and CHD incidence represent etiologically significant relationships. In the multifactorial causation of this disease at least four major factors are operative; diet high in cholesterol and saturated fat, hypercholesterolemia, hypertension and cigarette smoking. However, since the data from both animal and human studies indicate that high blood pressure and cigarette smoking are minimally significant in the absence of the nutritional metabolic prerequisites for atherogenesis, it is further reasonable and sound to designate ‘rich diet’ as a primary, essential, and necessary cause of the current epidemic of premature atherosclerotic disease ranging in the Western industrialized countries.
I would only argue that Senators don´t have the luxury that a research scientist does of waiting until every last shred of evidence is in.
Although Minger would try to have readers believe that a significant portion of the experts at the time were not in favor of the diet-heart hypothesis, evidence strongly suggests otherwise. As pointed out by Plant Positive in his new series of videos, in December 1976, just before the publication of first edition of the dietary goals, Dr. Kaare R. Norum conducted a survey to confirm how supportive the experts in the field were of the validity of the diet-heart and lipid hypotheses. Out of 211 epidemiologists, nutritionists and geneticists who received the survey, 193 recipients from 23 different countries responded.32 The list of surveyed recipients was considered to have included virtually every prominent researcher in the field from the time.33 As a result of this survey, Norum asserted that:
Almost all agreed that there is a connection between diet and the development of CHD, between diet and plasma lipoprotein levels, and between plasma cholesterol and the development of CHD.
Failing to Meet Her Own Demands
Although there is definitely room for significant improvements in the federal guidelines, Denise Minger’s suggestions for improvements are a step in the wrong direction. It is for this reason that it is not possible to recommend this book to anyone interested in health. In conclusion, it appears that Minger is more interested in promoting shoddy science than those who designed the food pyramid.
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