Forks Over Knives and Healthy Longevity: Perhaps the Science is Legit After All

This is the second part of a series of posts that addresses the science regarding plant based diets and the documentary Forks Over Knives and the very serious inaccuracies and omissions that compromise the critiques authored by the cholesterol skeptics, in particular Denise Minger.

Part I: Forks Over Knives: A Missed Opportunity for the Cholesterol Skeptics

Denying the Preponderance of Evidence

Large systematic reviews of the nutritional literature authored by major international health authorities and by panels of leading nutrition researchers, many of which have disclosed ties to livestock industry, have consistently come to the conclusion that diets should be predominately plant based.1 2 3 4 The documentary Forks Over Knives features a number of doctors who have come to the conclusion that the allowance of animal foods in ‘small-to-modest’ amounts (made by researchers who often have financial ties to the livestock industry) are too permissive and that an optimal diet should be almost entirely composed of minimally refined plant foods. They also conclude that many major chronic and degenerative diseases that affluent populations succumb to can be prevented, and in many cases even reversed by consuming a whole-foods plant based diet. For the vast majority of nutritional researchers the question is no longer as to whether a plant based diet or an animal based diet is more optimal, but as to what the upper tolerable intake is in an optimal diet for foods not derived from minimally refined plant foods.
Many leading nutritional researchers and prominent health authorities actually do agree that the medical literature supports many of the dietary recommendations made by the doctors in Forks Over Knives, but are often unable to make similar recommendations to the public, in part due to socioeconomic factors. For example, Eric Rimm from the Department of Nutrition, Harvard said to Reuters in regards to a major health report produced by the National Academy of Science, which he was an author of that:

We can’t tell people to stop eating all meat and all dairy produces. Well, we could tell people to become vegetarians… If we were truly basing this on science we would, but it is a bit extreme.

Similarly, Walter Willett, the Chair of the Department of Nutrition, Harvard previously said in regards to findings on cancer that:

If you step back and look at the data, the optimum amount of red meat you eat should be zero.

Diethelm et al. published an excellent reviewaddressing the five characteristics of denialism. The first characteristic describes how the cholesterol skeptics attempt to downplay the scientific consensus regarding the disease promoting effects of elevated LDL cholesterol and animal based diets rich in saturated fat:

The first is the identification of conspiracies. When the overwhelming body of scientific opinion believes that something is true, it is argued that this is not because those scientists have independently studied the evidence and reached the same conclusion. It is because they have engaged in a complex and secretive conspiracy.

The cholesterol skeptics will also attempt to downplay the scientific consensus often by insisting that scientists are ignoring certain studies, studies which these denialists fail to mention are compromised by a number of very serious flaws and omissions.5 6 7 Diethelm et al. also explains the motivations behind denialism:

Denialists are driven by a range of motivations. For some it is greed, lured by the corporate largesse of the oil and tobacco industries. For others it is ideology or faith, causing them to reject anything incompatible with their fundamental beliefs. Finally there is eccentricity and idiosyncrasy, sometimes encouraged by the celebrity status conferred on the maverick by the media.

Perhaps the cholesterol skeptics persistent denialism can be explained by conflicts of interest associated with the sales of merchandise or the desire for celebrity status on the internetBrownell et al. reminds us how serious and real conflicts of interest are, describing the tactics used by the tobacco industry, who for decades attempted to dismiss the ‘junk‘ science linking smoking to lung cancer and other associated diseases, whose personal gain from this caused millions of people to perish. They asserted:8

A striking event occurred in 1994 when the CEOs of every major tobacco company in America stood before Congress and, under oath, denied believing that smoking caused lung cancer and that nicotine was addictive, despite countless studies (some by their own scientists) showing the opposite.

This merits exploration as to whether the cholesterol skeptics motivations are any different than these other denialists, and whether many of the hundreds of peer-reviewed papers they also dismiss as ‘junk‘ science are actually informative and contain potentially life-saving findings.

Hormone Free, Pasteurised Animal Foods and Primitive Populations

Cholesterol skeptics will often claim that the results of any study suggesting harmful effects of animal foods were obscured due to participants consuming unnatural foods produced by intensive farming practices. The cholesterol skeptics however provide scant evidence regarding the perpetrated health benefits of replacing whole plant foods with naturally produced animal foods. Studies cited throughout both Part I of this review and this current post demonstrate that the association between replacing minimally refined plant foods with animal foods and poorer health expectancy can largely be explained by the fact that animal foods are typically naturally rich in methionine, dietary heme, saturated fat, dietary cholesterol, ruminant trans-fat, and hormones, and deficient in dietary fiber, antioxidants, carotnoids and phytochemicals, just to name a few.

A number of studies that have actually found some of the strongest associations between animal food intake and an increased risk of chronic diseases were actually carried out in populations where livestock is primarily grass fed and administration of hormones to livestock are banned by law, such as in Uruguay.9 10 11 12 These studies cannot simply be explained as exceptions as they are consistent with evidence from before thewidespread use of intensive farming practices that produce unnaturally raised livestock.

In 1892 the renowned French geographer, Reclus noted that:13

…cancer is most frequent among those branches of the human race where carnivorous habits prevail.

In 1908, Williams published an extensive review of the medical literature and documentation from a large number of populations around the world in regards to the causation of cancer, and came to conclusions that were consistent with Reclus’s findings:14

Careful study of the life-history of centenarians and of persons of advanced age who, as we have seen, are very rarely the victims of cancer shows that they are generally of spare figure, medium height, and that they eat frugally, taking but little meat and alcohol.…In this connexion, it may be well to recall the fact, that although cancer is remarkably rare in vegetarian communities, yet complete exemption cannot be claimed for such ; and the like is true of herbivorous, as compared with carnivorous animals. In spite of these facts, which indeed are only such as might have been expected from the essential nature of the problem, there cannot be the slightest doubt in face of the overwhelming evidence I have adduced in the course of this work that the incidence of cancer is largely conditioned by nutrition.

In 1925, Kuczynski described the poor health of a population who subsisted on a diet based predominantly on organic pasteurized animal foods. As later described by Stamler:15

Kuczynski (1925) reported on an Asian population at the opposite end of the dietary spectrum – nomadic Kirghiz plainsmen who habitually consumed large amounts of meat and milk. He noted high incidence of obesity, premature extensive atherosclerosis, contracted kidney, apoplexy, and arcus senilis. Their urbanized kinsmen, subsisting on more varied fare, did not exhibit such severe vascular disease.

In 1932, Raab noted in regards to the distribution of atherosclerosis, that:

…the relative rarity of atherosclerosis and hypertension among the chiefly vegetable-consuming inhabitants of China, Africa, Dutch East India, and the enormous frequency of arteriosclerosis and hypertension among the peoples of Europe and North America who consume large quantities of eggs, butter…
In 1934, Rosenthal reviewed 28 papers from observations carried out around the world, and reached a conclusion that was consistent with Raab’s findings, noting that:16

…in no race for which a high cholesterol intake (in the form of eggs, butter and milk) and fat intake are recorded is atherosclerosis absent…

In 1940, based on years of clinical practice and reviewing medical reports, Bertelsen who is considered the father of Greenland epidemiology stated in regards to the mortality patterns amongst the Greenland Inuit that:17 

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

In 1904, Bertelsen proved the existence of cancer in the native Inuit, diagnosing a case of breast cancer. During the following decades researchers documented that the existence of cancer was exceedingly common among the Inuit despite their relatively short life expectancy.18 Consistent with Bertelsen’s findings, an Inuit predating western contact who was mummified in approximately 1475, 450km north of the Arctic Circle was shown to have evidence of cancer, likely of the breast.19 It has also been documented that numerous preserved pre-contact Inuit who were mummified dating all the way back to 1,500 years ago had a severe degree of atherosclerosis, osteoporosis, and osteoarthritis, consistent with studies of Inuit living in the 20th century.20 21 22 23 Other evidence of poor health among the pre-contact Inuit includes iron deficiency anemia, trauma, infection, dental pathology, and children with downs syndrome and Perthes disease.24 25

A large number of the examined mummies from ancient Egypt have also provided clear evidence of atherosclerosis in ancient civilizations. Unfortunately some researchers have previously confused the diets of the mummified elites of ancient Egypt who exhibited atherosclerosis with the plant based diets of the lower classes of Egypt.26 More recent research on the interpretations of the ancient Egyptian hieroglyphs and isotope analysis of hair samples from the mummies has provided strong evidence that the elites of Egypt, being those primarily mummified consumed a diet rich in meat and saturated animal fat.27 28 29 The researchers asserted that:

It is important to point out that there was a marked difference between the mainly vegetarian diet most Egyptians ate and that of royalty and priests and their family members whose daily intake would have included these high levels of saturated fat. Mummification was practised by the elite groups in society, ensuring that their remains have survived to provide clear indications of atherosclerosis; by contrast, there is a lack of evidence that the condition existed among the less well-preserved remains of the [mainly vegetarian] lower classes.
The following videos (Videos 1-6) are from the very inspirational Primitive Nutrition Series produced by Plant Positive, providing further details that address the very serious flaws and omissions that compromise the claims from advocates of animal based diets regarding primitive population studies.