Denise Minger: Death By Food Pyramid or Saved By Food Pyramid?

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.1 This 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.

One reason Minger’s critique likely received much attention, was that unlike other individuals who have attempted to criticize the China Study, rather than making her intention of defending a diet rich in animal foods obvious, Minger attempted to give readers a false impression that if anything she was bias towards a plant-based diet. Minger’s intentions became somewhat apparent when Paleo diet proponent Richard Nikoley posted an e-mail that he received from Minger on his blog.2 The contents of this e-mail made it obvious that Minger had been sending e-mails to proponents of Low-Carb and Paleo diets, suggesting that they cite her blog post as "ammo" to shoot down "vegans" who cite The China Study. The language used by Minger in the e-mail, such as the statement “Of course, they aren't”, in reference to whether animal foods are linked to chronic diseases, suggested the likelihood of confirmation bias in favor of downplaying the harms of animal foods. This raises the question as to whether it was her intention to simply downplay Dr. Campbell’s work, rather than producing an honest review.

As described previously by Plant Positive, and myself, 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".3 The 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.4 It 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 before hormone 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.

Given Denise Minger’s misleading blog posts, naturally I was more concerned than interested to see what sort of take home message Minger would be attempting to provide readers of her recently published book, Death By Food Pyramid. I have therefore decided to review a number of the key sections of the book to help readers to decide whether to purchase and incorporate the dietary advice in this book.

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.7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

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 22 23 The 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...

Epstein also noted that during this period the prevalence of smoking among women remained largely unchanged or increased in most nations, and that therefore changes in smoking prevalence was unable to explain the large differences in the rate of decline between countries and sexes.24

Figure 1. In the United States between 1980 and 2000, changes to serum cholesterol resulting from dietary changes had a greater impact on the decline in coronary heart disease mortality than any other factor, resulting in approximately 1.1 million years of life gained. 

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).7 22 Considering 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 the chapter Amber Waves of Shame, Denise Minger attempts to explain about the implementation of the Dietary Goals for the United States of 1977, also known as McGovern Report. This report has been considered by many as laying a cornerstone for the forthcoming USDA guidelines. In this chapter, Minger also describes how the egg, meat, milk, salt and sugar industries attempted to hijack the report due to the nature of the recommendations to limit these foods, referencing a video on this topic by Dr. Michael Greger which can be viewed below. It comes as no surprise that Minger cited this video but chose to neglect many of the hundreds of studies cited throughout Dr. Greger's series of videos that cast significant doubt on her own dietary recommendations.

Dr. Michael Greger on the McGovern Report

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.

Minger quotes several selected sentences from the paper on dietary fat and heart disease by ASCN panelist Charles J. Glueck regarding the failure of several diet-heart trials to produce unequivocal supportive evidence, suggesting as if Glueck concluded that there was scant evidence supporting the diet-heart hypothesis. This however was not the case. Glueck actually indicated that while it can be considered that there may not have been unequivocal evidence supporting the diet-heart hypothesis, there was some strong suggestive evidence. In fact, in the paper Minger cites, Glueck described why the failure of the diet-heart trials to produce statistical significant findings does not necessarily negate the hypothesis:27

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.

In a different paper published in the same issue of the American Journal of Clinical Nutrition, Glueck cited several lines of strong suggestive evidence supporting the diet-heart hypothesis. Notably, Glueck stated:28

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

Considering that there is “unequivocal causal” evidence from experiments on nonhuman primates, naturally this would be of considerable concern for humans. If a similar harmful effect would to be shown for a food additive, especially at intakes even lower than that typically consumed in developed nations, there is little doubt that it would be banned almost immediately. Furthermore, in this same paper, without expressing significant disagreement, Glueck quoted the conclusions of a review of the epidemiological evidence by Jerimiah Stamler, one of the expert advisors for the McGovern Report:28

…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.

As has been the case for smoking, there has never been, and never will likely be a definitive trial which tests the diet-heart hypothesis. Indeed, the few smoking cessation trials that have been carried out have failed to produce statistically significant findings for lung cancer mortality. Some of these trails even produced paradoxical findings, including non-significant increased rates of mortality from lung cancer and other cancers in the cessation group.29 30 Similar to the diet-heart trials, there are however plausible explanations as to why these trials failed to demonstrate significant findings for the benefits of smoking cessation. Such explanations include an insufficient duration of study period, and only modest differences in risk factors, points that Glueck noted as limitations of the trails testing the diet-heart hypothesis.29 30 This illustrates why it is critical to consider the totality of evidence, as negative findings from certain lines of evidence, even when normally considered to be at the top of the hierarchy of evidence does not necessarily negate a hypothesis. In other words, the lack of unequivocal evidence should not necessarily prevent federal agencies from recommending lifestyle changes to the public. This point was made clear by Senator George McGovern when he responded to criticism of the report, asserting that:31

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.

Minger also attempts to downplay the McGovern Report by taking the statements made by members of the McGovern Committee out of context. For example, Minger focuses on the statements of McGovern Committee member Chris Hitt who believed that even in the worst case scenario, that at the very least "the goals were safe, that there were no risks". Minger then takes this statement out of context to suggest as if the committees opinion of the likely effectiveness of the guidelines had more or less became “at least this probably won’t kill everybody”[p.43]. This statement, which suggests that the guidelines are not only ineffective, but are potentially dangerous, is clearly not what Chris Hitt stated, and is a far stretch from the opinion of committee as a whole.

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.

It is clear that Minger is trying to give the reader the false impression that the McGovern Committee, the ASCN expert committee, and a large portion of experts in this field felt that the guidelines of the McGovern Report, particularly the guidelines regarding the restriction of cholesterol and saturated fat were not evidence based by taking selected statements made by a number of these experts out of context. These tactics were perhaps used in order to give the reader the false impression that, even from the beginning, the federal guidelines have never been evidence based, providing momentum for the rest of her book. As can be seen from the table below based on Norum's survey, the impression that Minger attempts to provide the reader of the expert opinion of the time should be considered as misleading.

Failing to Meet Her Own Demands

In Death By Food Pyramid, Denise Minger criticizes the federal dietary guidelines, such as those to restrict dietary cholesterol and saturated fat, not so much due to a lack of high quality suggestive evidence, but due to the lack of unequivocal evidence. At the same time, Minger fails to provide any unequivocal evidence to support her own dietary recommendations, recommendations that she seems to suggest should be adopted into the federal guidelines. Minger also suggests that observational studies help little to determine causation when reviewing studies that cast doubt on her recommendations, yet often cites observational studies as the primary line of evidence to support her own recommendations. The fact that Minger is so demanding of the quality of evidence for those federal dietary guidelines that she disagrees with, while having far looser criteria for evidence supporting her favored hypotheses suggests the likelihood of denialism.

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.

More on Death By Food Pyramid

Do Vegetarians Live Longer Than Health Conscious Omnivores?

Please post any comments in the Discussion Thread.

The Asian Paradox: End of the Line for Low Carb Diets?

The fact that the populations of many parts of Eastern and Southeast Asia have traditionally been slim while consuming a high carbohydrate diet, typically rich in white rice is often considered as a ‘Asian Paradox’ by advocates and followers of carbohydrate restricted Low-Carb, Paleo and Primal type diets who hypothesize that such a dietary pattern promotes weight gain. Mark Sisson, a prominent Paleo diet advocate recently explained that the so-called ‘Asian Paradox’ is not a paradox because he believes that Asians have traditionally conformed to a lifestyle and diet that is comparable with his recommendations.1

Sisson attributes the leanness and health of the traditional living Asians to regular exercise and a diet rich in unprocessed foods including fresh meat, offal, bone broth as well as vegetables, with rice playing a neutral role. In addition, Sisson attributes much of the observed increases in rates of obesity, diabetes and coronary heart disease in Asia in more recent years to an increased intake of sugar, and the replacement of rice with wheat and saturated animal fats with omega-6 rich fats. However, Sisson provided scant evidence to support his claims regarding the composition of traditional and modern diets in Asia. Considering that obesity, diabetes and cardiovascular disease are major causes of disability and death throughout the world, this warrants an examination of these claims.2

Concerns of Low-Carb and Paleo Diets

Mark Sisson sells whey protein, among many 
other supplements. These supplements were 
certainly not available to Paleolithic humans.

Sisson advocates a diet that is rich in animal protein and fat and poor in carbohydrate. Sisson has an 80/20 rule which allows 20% of dietary intake from non-Paleolithic foods from his list of approved foods, including items such as full-fat dairy, chocolate, coffee and wine, as well as the supplements that he sells. Sisson would have his targeted audience believe that humans have conveniently adapted to many foods that were not typically available during the Paleolithic period which are popular among followers of low-carb diets, but not the foods that they typically shun. As such a dietary composition is probably not coincidentally all that different from other popular carbohydrate restricted diets, this makes the diet that Sisson promotes essentially in one variant or another a rebranded Atkins diet. Aside from the lack of originality, there is an ever-increasing amount of evidence demonstrating harm of such a diet. 

It is well established that weight loss has a modest favorable effect on many cardiovascular risk factors.3 4 5 Therefore the modest beneficial changes to cardiovascular risk factors observed in participants on carbohydrate restricted diets in some controlled trials can be either partly or wholly explained by weight loss. However, even in the presence of slightly greater weight loss, meta-analyses of randomized controlled trials have found that compared to diets rich in nutrient poor, low-fiber carbohydrates, carbohydrate restricted diets raise LDL cholesterol and impair flow-mediated dilatation, a measure of endothelial dysfunction which can increase the risk of cardiovascular disease.6 7 In addition, a recent intervention study on a Paleo type diet that contrary to previous intervention studies, did not focus on reducing saturated fat intake found that a Paleo diet significantly raised non-HDL cholesterol and the total cholesterol/HDL ratio despite weight loss and adherence to an exercise regime.8

The findings of a harmful effect on flow-mediated dilatation are consistent with several other controlled experiments which found that diets rich in saturated fat, including when consumed in a carbohydrate restricted diet impaired flow-mediated dilatation.9 10 11 12 13 These findings are also supported by experiments showing that diets rich in cholesterol and saturated fat cause endothelial dysfunction in numerous species of nonhuman primates.14 15 16 Taken together, these findings lend support to the findings that carbohydrate restricted diets adversely affect coronary blood flow, arterial wall function and cardiac efficiency.17 18 19

The findings of a harmful effect on LDL cholesterol are consistent with the findings from hundreds of controlled experiments establishing beyond plausible doubt that a diet lower in saturated fat, ruminant trans-fat, dietary cholesterol, and richer in soluble fiber and plant sterols significantly reduces total and LDL cholesterol.20 21 22 23 24 25 It has also been established beyond plausible doubt that lowering LDL cholesterol reduces the risk of coronary heart disease.26 However, this effect is likely to be considerably stronger the longer LDL cholesterol is maintained at a lower concentration.27 28

A meta-analysis of 108 lipid intervention trials with 300,000 participants and a mean follow-up of only three years found that for each 1 mmol/l (38.7 mg/dl) reduction in LDL cholesterol, coronary heart disease and all-cause mortality was reduced by 24% and 15% respectively, independent of HDL cholesterol, triglycerides and non-lipid effects of specific interventions.29 Comparatively, a meta-analysis of mendelian randomization studies with more than 312,000 individuals found that for each genetically predicted 1 mmol/l reduction in LDL cholesterol maintained throughout life, coronary heart disease was reduced by 55%, independent of the mechanism by which LDL was modified and other known risk factors.30 Conversely, both randomized controlled trials and mendelian randomization studies have been unable to establish a causal relationship between HDL cholesterol and triglyceride concentrations and coronary heart disease.29 31 32

Experiments on animals have found that carbohydrate restricted diets accelerate the development of atherosclerosis independently of traditional risk factors.33 Furthermore, evidence from thousands of experiments carried out over the last century have shown that the feeding of dietary cholesterol and saturated fat has accelerated the development of atherosclerosis in virtually every vertebrate species that has been sufficiently challenged. This includes mammalian, avian and fish species- herbivores, omnivores and carnivores, and over one dozen different species of nonhuman primates. 

Nations throughout Australasia, Europe and North America have experienced very dramatic declines in coronary heart disease mortality throughout the last half century, for which a substantial portion of the decline has been explained by a dietary induced reduction in serum cholesterol.34 35 After a decade of steady increases, the rates of coronary heart disease mortality in the Czech Republic and Poland fell almost immediately and halved within about 15 years following the abolishment of communist subsidies on meat and animal fats after the collapse of the Soviet Union. Nearly half of this decline has been explained by decreases in serum cholesterol.36 37 In the Nordic nations the rate of coronary heart disease mortality decreased by about 50-85% within three decades following Government initiatives which included a reduction in saturated fat intake. In Finland, Iceland, Norway and Sweden the decreases in serum cholesterol was the main contributor explaining between about one-third and more than half of this decline.38 39 40 41

Contrasting trends have however been observed in Tunisia and Beijing. Tunisia has recently experienced a significant increase in coronary heart disease mortality, of which half of this increase has been explained by an increase in serum cholesterol following a transition from the traditional wheat based diet to a diet richer in animal protein and fat.42 In Beijing where the rates of coronary heart disease mortality increased by more than 100% between 1984 and 1999, the great majority of the increase was explained by an increase in serum cholesterol following a five-fold increase in intake of meat and eggs (Fig. 1).43

Figure 1. Coronary heart disease mortality trends in Beijing 1984 to 1999

Over the last decade the population of Sweden has been shifting to a diet lower in carbohydrate and higher in fat, especially from animal sources following much positive media support for low carbohydrate-high-fat (LCHF) diets. However, despite promises of rapid weight loss, not only has there been no change to the constant increase in BMI, there has actually been an increase in serum cholesterol despite an increased use of cholesterol lowering medication.44

Following the dietary transition in Sweden there has been a sudden surge in heart attacks in women, and stoke in men and women aged 35-44 despite steady decreases in smoking prevalence in this age group, especially for women.45 This has been a great cause of concern for a number of prominent Swedish cardiologists who have attributed this to the significant increase in the popularity of LCHF diets.46 Similar concerns were raised when there was a sudden surge in sudden cardiac death among women, also aged 35-44 in the United States during the period of heightened popularity of the Atkins diet.47 48

As younger adults are considerably less likely to be treated for risk factors prior to a cardiovascular event, they may be more vulnerable to these dietary changes, possibly explaining why they have been the first group in the Swedish population to experience these adverse effects following the dietary transition. The finding that particularly young women were adversely affected may be because young women were among the first groups in the population to make this dietary transition, and also because LCHF diets are considerably more popular among Swedish women than men.44 49

Another concern with diets that are rich in meat and offal is an excess intake of heme iron, found exclusively in animal tissue. As iron is a pro-oxidant and excess iron cannot be excreted from the body, excessive absorption of iron can contribute to progressive inflammatory and degenerative diseases.50 It has been shown in controlled feeding experiments that the absorption of heme iron is considerably less regulated than that of non-heme iron, and therefore a high intake can lead to excess iron absorption.51

Recent meta-analyses of prospective cohort studies found that an increment of 1 mg/day of heme iron was associated with an 11%, 16% and 27% increased risk of colorectal cancer, type II diabetes and coronary heart disease respectively.52 53 54 When taking into consideration the fact that diets very rich in meat and offal can supply well over 10 mg of heme iron per day, these findings cast considerable doubt on the long-term safety of such diets.55 Heme iron intake has also been associated with oxidative stress and an increased risk of stroke, gestational diabetes, gallstones and cancers of the prostate, lung, stomach, esophagus, endometrium and kidneys.56 57 58 59 60 61 62 63 64 65 66 67 68 69

It has been shown in a randomized controlled trial that carbohydrate-restricted diets promote metabolite profiles that may increase the risk of colorectal cancer.70 This is compatible with the strong evidence from both controlled experiments and prospective cohort studies that diets richer in heme iron and poorer in dietary fiber increase the risk of colorectal cancer. Over a century ago, high rates of cancer were observed in Argentina which was inhabited by the Gaucho, a nomadic population that for months subsisted entirely on pasture raised beef. Similarly, a study carried out in Uruguay where livestock is predominantly grass fed, and the administration of hormones is banned by law found that a high intake of fresh red meat was associated with between a 87% and 290% increased risk of 13 different major cancers, independent of other food groups.71

Another concern of diets rich in animal protein is that they can have adverse effects on phosphorus balance in the presence of declining kidney function, contributing to very serious complications associated with kidney disease including cardiovascular disease and sudden death.72 A Cochrane review of randomized controlled trials with patients with chronic kidney disease found that compared to patients with unrestricted protein intake, patients who restricted protein intake had a 32% lower risk of kidney death.73 These findings are particularly concerning when considering that the prevalence of chronic kidney disease is estimated to be between 8-16% with approximately 735,000 deaths attributed to chronic kidney disease worldwide in 2010 alone.74 75 Even in developed nations a significant portion of chronic kidney disease cases go undetected.76

The potential harm of animal protein on kidney function is evidently only in part explained by the high phosphorus content. For example, it has been shown in several randomized controlled trials in patients with declining kidney function that even when protein and phosphorous intake is held constant, plant protein from grain and soy has a favorable effect on phosphorus balance and other markers of kidney function compared to animal protein.77 78 Consistent with these findings the Adventist Health Study 2 found that those who adhered to a vegetarian type diet had less than half the rate of kidney death compared to those who consumed meat regularly.79

Low-carb and Paleo type diets are often advocated as a means of weight loss. However, consistent with the long-term trends in Sweden, randomized controlled trials have found that compared to diets rich in nutrient poor, low-fiber carbohydrates, carbohydrate restricted diets provide little benefit in terms of weight loss in the long-term.80 81 As it has been shown in randomized controlled trials that an increase in intake of dietary fiber has favorable effects on body weight and a number of other cardiovascular risk factors, this suggests that had these trials focused on high-fiber carbohydrate rich diets, carbohydrate restricted diets would have been less likely to have compared favorably.82 83 84 85 Recently Don Matesz published an informative critique of the Paleo diet as a measure for weight loss. Notably Matesz mentions: 

Consequently, any Paleolithic humans who engaged in nutritionally motivated hunting would have done so in order to increase their food energy intake in order to maintain or gain weight, not in order to achieve weight loss… In view of this, the "Paleo diet" theory that overfed sedentary modern humans who need to lose excess adipose should regularly eat the fatty flesh and eggs found in supermarkets because active, underfed, extremely lean prehistoric people who struggled to meet their basic kcaloric needs ate lean game flesh or eggs whenever possible lacks basic credibility. 

Considering the evidence it is not surprising that many of the prominent proponents of Low-Carb and Paleo diets who unlike Sisson have not partaken in caloric restriction have gained considerable amounts of weight while adhering to such diets. 

Recently a meta-analysis of prospective cohort studies with more than 272,000 participants found that carbohydrate restricted diets was associated with a 31% increased risk of death from any cause.86 Sub-analyses suggested that carbohydrate restricted diets based on animal protein and fat was associated with an even stronger risk of death from any cause as well as death from cardiovascular disease. This was despite the evidence that animal protein and fat was primarily compared to refined rather than high-fiber carbohydrates, and there is data from over one million people in cohort studies demonstrating that dietary fiber and whole grain intake is associated with a significantly reduced risk of death from any cause. Although this meta-analysis was based on observational evidence, the abovementioned evidence from randomized controlled trials provides confidence for the validity of these findings, as do other lines of evidence cited previously. 

Considering the lack of evidence when compared to healthy alternatives of a significant long-term favorable effect on body composition and strong evidence of harm, especially when animal sources of protein and fats are chosen, there is little rational to promote these fad diets.

Meat as a Staple in Asian Diets

Traditional Kirghiz nomadic pastoralists

The evidence that Sisson provides to suggest that traditional Asian diets were rich in meat and offal is based on his observations of Chinese, Japanese, Korean, Thai and Vietnamese restaurants and Asian supermarkets in modern day United States. However, the food balance sheets from the United Nations for the early 1960s for these nations that Sisson makes special reference to, suggest that total animal food intake only amounted to between 2.5% and 10% of total caloric intake, with offal intake being almost non-existent.87 As earlier dietary surveys, especially prior to World War II suggest that intake of animal foods was even lower, this casts significant doubt on Sisson's suggestion that animal foods traditionally contributed to a large portion of these populations diets.88 89

Perhaps if Sisson would only visit a Mongolian Barbeque restaurant he would observe a meaty diet that is not only largely comparable with his recommendations, but also with the traditional diet of the nomadic pastoralists of Mongolia, Central Asia and northern China. It has been observed however that many of these nomadic populations who subsist largely on pasture raised animal foods have high rates of obesity and cardiovascular disease, and this has been frequently associated with their meaty diets.90 91 92 Some of these observations were made at least as far back as ninety years ago.

In the 1920s, it was observed that the nomadic pastoralists of the Kirghiz and Dzungarian Steppes in Central Asia and northern China subsisted almost exclusively on enormous amounts of fermented mare’s milk and meat from pasture raised animals. Not only was a high rate of obesity observed, but also high rates of premature extensive atherosclerosis, contracted kidney, apoplexy, arcus senilis, and gout. These pastoralists were often observed to suffer from complications related to cardiovascular disease even in their early thirties. In contrast, their urban counterparts who based their diet on soup, bread, pickles, and potatoes with very little meat were observed to be slim, free of cardiovascular disease and had very good health, even into their seventies when they were still sexually active.

It was observed that in the 1960s the rates of coronary heart disease of the nomads from Xinjiang in northern China who largely subsisted on pasture raised animal foods was more than 7 times higher than that of other populations both within Xinjiang and throughout China which had a much lower intake of animal fat.93 These findings from non-industrialized populations in Asia are compatible with the observations of a high rate of cardiovascular disease among the Inuit populations whose staple is marine animals.94 In 1940, based on decades of clinical practice and his review of reports of medical officers dating all the way back to 1838, Bertelsen, who is considered the father of Greenland epidemiology stated in regards to the mortality patterns among the Greenland Inuit that:

...arteriosclerosis and degeneration of the myocardium are quite common conditions among the Inuit, in particular considering the low mean age of the population.

It is clear that these populations who traditionally subsisted predominantly on large amounts of naturally raised animal foods that the Low-Carb and Paleo proponents such as Sisson promote are not a good role model of health.

Wheat as a Staple in Asian Diets

Unleavened bread, the traditional Bedouins
predominant source of food

There had been a considerable amount of research carried out in regards to diet and the health of populations within the greater Asia region that consumed a semi-vegetarian diet based largely on wheat. Examples include the Arab Bedouins and Yemenite Jews, both of which traditionally consumed on average more than 500 grams of bread per day.95 These populations are known for their exceptionally low rates of coronary heart disease and obesity when following their traditional wheat based diet. Perhaps the largest consumers of wheat that there is considerable data available for are the Bedouins from southern Israel. The great majority of the dietary intake of the traditional Bedouins comes from wheat, typically in the form of full-grain bread, which is especially the case for the poor who eat very little else. It was estimated that the Bedouins traditionally consumed on average 750 gm, or the equivalent of 25 slices of full-grain bread per day.95

The traditional Bedouins had many dietary traits besides an extremely high intake of whole-grain wheat that are considered by advocates of Low-Carb and Paleo diets as being primary causes of obesity and the so-called ‘diseases of civilization’, including diabetes and coronary heart disease. For example sugar intake was observed to be modestly high, a trait comparable to that of the populations in Colombia, Cuba and Venezuela who have traditionally had among the highest rates of per capita sugar consumption in the world and low rates of coronary heart disease mortality.96 97 It was estimated that dietary cholesterol intake was only 53 mg/day and saturated fat was less than 3% of caloric intake, suggesting that animal foods as a whole contributed very little to the Bedouins diet. Meat was consumed only about once per month, and virtually never eaten by the poor. Similarly egg and especially fish intake was very infrequent, although animal milk is frequently consumed. Fat intake only contributed to about 11% of total caloric intake, with a relatively low intake of omega-3 fat and a high ratio of omega-6/omega-3 fat. Vitamin A intake was very low, and for the many women who virtually never exposed their skin outside, blood concentrations of vitamin D would have likely been on the low side.96

It has been documented that diabetes and heart attacks were all but entirely absent in the traditional living Bedouins which had an average serum cholesterol of 4 mmol/l (155 mg/dl), and that the great majority of the population were exceptionally lean by western standards, both in terms of weight and skin thickness.96 98 The rates of inflammatory bowel disease were also considered to be very low.99 The few Bedouins that were observed to be obese were exclusively the wealthier elderly who rarely even walked. Being a semi-nomadic population that largely relied on walking as a means of transport, exercise has been suggested as one explanation for their exceptional low rates of obesity. However, many of the women were forced to stay inside their tents all day allowing for little exercise, yet these women with almost no exceptions were slim and free of vascular disease.96 

Researchers believe that it is the Bedouins small appetite that partly contributed to their exceptional leanness.96 Considering that about 90% of caloric intake was derived from full-grain wheat suggests that the wheat consumed was not a low satiety food, nor was it fattening. This hypothesis is consistent with the findings from a recent review of 38 epidemiological studies that found suggestive evidence that whole-grain bread intake favorably influences body weight.100 Similarly, a number of controlled experiments found suggestive evidence that wheat bread assists with satiety and weight loss in low-calorie diets.101 102 103 In addition, a recent large systematic review found that whole-grain cereals and bread are associated with a significantly decreased risk of colorectal cancer, type 2 diabetes and cardiovascular disease.104

One clear downside of the Bedouins traditional diet was a very low intake of fruits and vegetables. Although an increased intake of fruits and vegetables would likely have helped to prevent a number of potential vitamin deficiencies and improved overall health, it is clear that the traditional Bedouins were very slim and had very low rates of diabetes and heart disease despite consuming a diet that Sisson considers as a primary cause of diseases of civilization. 

Sisson referred to an article from a blogger, Ned Kock who analyzed the data from the China Study II with minimal control for confounding factors and found a positive association between wheat flour intake and cardiovascular disease mortality. However, Michel Blomgren, a statistics enthusiast who conducted a much more comprehensive analysis found that intake of wheat and a number of other staple grains were associated with a decreased risk of ischemic heart disease mortality.105 The opposite was found for animal protein and both animal and vegetable fat (Fig. 2).

Figure 2. Various foods and nutrients and risk of ischemic heart disease in a multivariate regression analysis in the China Study II, ages 35-69

Although these findings may contrast the more simple analyses produced by people like Ned Kock and Denise Minger, the greater consistency with other ecological studies, as well as other lines of evidence described previously does provide some confidence for the validity of these findings.106 107 This is not to say that this analysis is without its limitations, nor to say that an analysis with a similar degree of control examining all causes of cardiovascular disease mortality would not be more informative. However, when considered together with all other lines of evidence, this suggests that a modest intake of whole-grain wheat can be part of a health promoting diet for most people. These contrasting findings may not be considered to be all that surprising when considering that animal food intake was very strongly associated with favorable socioeconomic factors, with household income explaining up to 80% of the variance of intake between counties. Such favorable socioeconomic factors were not typically enjoyed in those counties with higher intakes of wheat, which would inevitably have had an unfavorable influence on cardiovascular disease mortality.108

In the China Study, a higher wheat intake can probably be considered as a marker of a higher concentration of certain ethnic groups, such as those from Central Asia living in northern China. Without specific data on the ethnic breakdown of each county, this makes it difficult to determine how ethnicity may have impacted these findings. However, a number of studies examining people within some of the major ethnic groups living in northern China have investigated the association between dietary factors and obesity and other cardiovascular risk factors. For example, a study found that within several ethnic groups living in Xinjiang, the region with the highest average BMI in the China Study and home to a number of nomadic populations, meat intake was associated with an increased risk of obesity, consistent with studies carried out in other regions of northern China.90 109

Although it is clear that a small portion of the population, such as those with celiac disease will benefit from eliminating wheat from their diet, there is no need to resort to making up nonsense as Low-Carb and Paleo diet advocates such as Sisson and Wheat Belly author William Davis have done about whole-grain wheat being a primary cause of obesity and diseases of civilization.110 111 The idea that whole-grain wheat should be replaced with fatty meats and eggs is clearly a step in the wrong direction, and there are certainly better alternatives for people who cannot tolerate wheat.

What is the evidence?

The assertion that the populations of Eastern and Southeast Asia were traditionally slim and healthy while consuming a high carbohydrate diet is somehow a paradox suggests that populations in other parts world have not thrived on a high carbohydrate diet. Such a suggestion ignores the evidence from healthy populations all throughout the world.

As Sisson correctly pointed out, there has been a surge in the rates of obesity, diabetes and other chronic diseases in Asia in recent decades (Fig. 1). Sisson suggests that this surge could partly be explained by changes to dietary habits, but provides scant evidence to support his claims. This merits further exploration into how the trends in dietary habits may have had an impact. As the intake of not only several of the items mentioned by Sisson, but also animal foods, especially meat has increased dramatically in Eastern and Southeast Asia over the last half century, naturally emphasis on how this has impacted the health of these populations has been the focus of much research. Part II of this review will focus on the composition of traditional diets in Asia and how certain dietary and lifestyle changes may help explain this epidemic of obesity and chronic diseases sweeping across Asia.


Please post any comments in the Discussion Thread.

Plant Positive Strikes Back: Nutrition Past and Future

Plant Positive has released a brilliant new series on YouTube titled 'Nutrition Past and Future', featuring 44 videos that address the misleading claims of Paleo, Primal and Low-Carb diet advocates including Gary Taubes, Robert Lustig, Loren Cordain, Mark Sisson, Robb Wolf, Andreas Eenfeldt, Anthony Colpo, and members of the Weston A. Price Foundation among others. This new series expand on Plant Positive's two previous video series, 'The Primitive Nutrition Series Playlist' and 'The Primitive Response Playlist'.

The Journalist Gary Taubes

Taubes gained prominence as an advocate of the low-carb diet following the publication of his article "What If It's All Been a Big Fat Lie?" in the New York Times in 2002. A follow-up article expressed the concerns of scholars that Taubes interviewed who complained that Taubes misinterpreted their statements and ignored much of the research that they presented, including research linking red meat with colorectal cancer. It was already clear from this point that Taubes was a snake oil salesperson and Plant Positive makes this fact even clearer in Nutrition Past and Future which in particular addresses Taubes's book Good Calories, Bad Calories. 

The Journalist Gary Taubes 1: Controlling History

Ancel Keys and John Yudkin

In Nutrition Past and Future, Plant Positive addresses the controversy over the classical research produced by Ancel Keys and John Yudkin. The first video below addressed Keys classical paper from 1953, Atherosclerosis: A problem in newer public health regarding the cross-sectional study of dietary fat intake and coronary heart disease mortality in six countries, not to be confused with the Seven Countries Study which was a longitudinal prospective cohort study published a number of years later. Plant Positive explains Keys views on nutrition and the literature at the time of this publication, as well as the plausible reasons as to why Keys selected the six specific countries to be included in the analysis. As Plant Positive explains, Keys omitted countries from the analysis that experienced major population shifts and changes to diet caused by the war, as well as those countries with very small populations. Keys also addressed this issue in a later in response to the international comparisons carried out by Hilleboe who included countries that had experienced these significant populations shifts and changes to diet.1

Plant Positive also pointed out that Keys limited the analysis only to countries that used reliable death records which classified deaths closely to that of international standards, and that Keys clearly asserted that:2

So far it has been possible to get fully comparable dietary and vital statistics data from 6 countries

Another point that the cholesterol skeptics ignore is that even when all the other countries were considered, intake saturated fat was still a strong predictor of coronary heart disease mortality [reviewed previously]. Even Hilleboe admitted this in 1957:1

Human diets with unrestricted fats, especially some of the saturated fatty acids, appear to be associated with coronary atherosclerosis, particularly in adult males

Keys however criticized Hilleboe's claim that this association ‘is not a causal relationship’ as Hilleboe provided scant evidence to refute the possibility of a causal relationship.1

The Journalist Gary Taubes 3: Ancel Keys Was Very Bad 1

The Journalist Gary Taubes 4: Ancel Keys Was Very Bad 2

As can be concluded from Plant Positive’s videos, it is ignorant to suggest that Ancel Keys cherry-picked these six countries without giving the reason for the selection criteria. In Denise Minger’s post regarding Ancel Keys 1953 paper where she attempted to plagiarize Plant Positive’s work, like Yerushalmy and Hilleboe, Minger ignorantly claimed that ‘Keys cherry-picked six countries and never told us why.’ It is clear that Minger has either simply not read or is ignorant of the data presented in the Keys paper that she criticized, yet still claimed that she ‘did a deeper analysis of the 1950s data than Keys himself probably did’.3 This is the same level of ignorance that Minger applied to her criticisms of the China Study [reviewed previously].

Plant Positive also provided an informative review of the controversy over John Yudkin's claims about sugar intake and the risk of  coronary heart disease.

The Journalist Gary Taubes 5: John Yudkin Was Very Good

In a later review, Keys again addressed Yudkin’s claims regarding sugar intake and coronary heart disease in international comparisons:4

In regard to international comparisons, there are countries with a high per capita consumption of sugar and of saturated fats; those countries tend to have high CHD death rates. And there are countries with low per capita sugar and saturated fat intakes; these have low CHD rates. When all these countries are put together, statistical calculation naturally shows CHD mortality is correlated with both sugar and fat intake. However, partial correlation analysis shows that when sugar is held constant, CHD is highly correlated with per capita saturated fats in the diet but when fat is constant there is no significant correlation between sugar in the diet and the CHD incidence rate. It should be noted, too, that Yudkin carefully avoids mentioning the fact that 2 countries with the highest per capita sugar consumption, Cuba and Venezuela, suffer low CHD mortality; it is notable that the dietary intake of estimated fats is low in both Cuba and Venezuela. 

Another flaw in Yudkin’s hypothesis about sugar and coronary heart disease that Plant Positive addressed was the contradictory evidence from animal experiments of atherosclerosis. When diets rich in dietary cholesterol and saturated fat, such as egg yolks are used to induce atherosclerosis in non-human primates, the atherosclerosis process has actually been reversed when these atherogenic components are replaced with chow very rich in sugar.5 6 This does not suggest that sugar should be considered a heart healthy food, but does emphasize the fact that sugar alone cannot induce atherosclerosis in the absence of dietary cholesterol and elevated blood cholesterol, and therefore cannot not explain the coronary heart disease epidemic.

Primitive Populations Revisisted

In Nutrition Past and Future, Plant Positive reviewed a number of high quality studies that strongly contradict the claims of low-carb advocates such as Taubes. These studies include the observations from the China Study and numerous earlier observations in China that are in general agreement with Dr. Colin Campbell's findings. For example, the observations that the nomadic Sinkiang in northern China who consumed diets rich in organic grass-fed animal foods experienced a 7 fold greater incidence of coronary artery disease than the Chinese living in Zhoushan Archipelago who consumed a diet much richer in plant based foods. These findings resemble even earlier observations from the 1920's of the nomadic plainsmen in Dzungaria in northwest China and across the border in Kyrgyzstan who consumed enormous amounts of organic grass-fed animal foods and experienced severe vascular disease at young ages [reviewed previously].

The Journalist Gary Taubes 15: Pesky Facts

In Nutrition Past and Future, Plant Positive provides an very informative analysis of the blood cholesterol in hunter-gatherer populations and the factors, such as parasites which are responsible for the observed low blood cholesterol in many of these populations. As Plant Positive addressed, George Mann contributed unnecessarily to the cholesterol confusion. Nevertheless, Mann has provided an excellent critique of a poor quality autopsy study authored by Biss et al. that cholesterol skeptics frequently cite to claim the traditional Masai did not develop atherosclerosis. Mann stated:7

Biss et al. have published their findings with 10 autopsies of "Masai" done at the Narok District Hospital in Kenya. They described "a paucity of atherosclerosis" with only "occasional fatty streaks and fibrous plaques" in subjects presumed to be Masai. The authors did not give details of selection of the subjects, a description of the causes of death, the methods of evaluation or even the ages. They measured the thickness of the coronary arteries with a caliper and found that "the Masais' coronary arteries had much thinner walls than those of whites in the U.S., matched for age and sex." Those measurements were not shown nor was the comparison population further described.

It is interesting that the cholesterol skeptics hail George Mann’s work as good science, but ignore this criticism about one of their frequently cited studies. Mann's critique suggests that the autopsies described in Biss et al. may not have even been carried out on Masai and that the authors did not even provide the information required to make an informed conclusion about the degree of atherosclerosis in this very small sample of people presumed to be Masai.

Ancestral Cholesterol 1

Ancestral Cholesterol 2

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