HOME
Refuting the idea that humans must be herbivores because only herbivores get cardiovascular disease
I was surfing the Internet recently, as you do, when I found a vegan website (30bananasaday.com) which presented an argument for humans being a herbivorous species — i.e. naturally vegans.
Vegans have such a hard time convincing most people that veganism is right that they will latch onto almost anything, it seems, to boost their case. And some of the things they come up with are quite convincing.
Like this one, for example.
While it looks to be a strong case in favour of our being a herbivorous species, it is actually quite misleading if you are not aware of a few basic facts. I have published verbatim the 'humans are herbivores' argument in the shaded area below; I have then added evidence which shows how wrong it really is.
World reknowned (sic) cardiologist shatters human omnivore myth in one sentenceWilliam C. Roberts MD has five decades of experience in the field of cardiology, written over 1300 scientific publications, a dozen cardiology textbooks, and has been editor in chief of the American Journal of Cardiology for a quarter of a century. He is arguably the most highly regarded cardiologist in the world today. In his 2008 editorial "The Cause of Atherosclerosis", published in the peer reviewed journal Nutrition in Clinical Practice, Roberts states that there is a single, sole cause to heart disease: cholesterol. If your total cholesterol is below 150 and LDL is below 70, you are essentially heart attack proof. What is the cause of high cholesterol? Saturated fat and animal products:
He elaborates in an earlier editorial:
It is virtually impossible, for example, to produce atherosclerosis in a dog even when 100 grams of cholesterol and 120 grams of butter fat are added to its meat ration. (This amount of cholesterol is approximately 200 times the average amount that human beings in the USA eat each day!). (The American Journal of Cardiology, 1990, vol. 66,896.) He then utterly annihilates the human omnivore myth in a single sentence. here it is: ***Because humans get atherosclerosis, and atherosclerosis is a disease only of herbivores, humans also must be herbivores.*** At once the insanity of our times comes into razor sharp relief. Some may debate whether cholesterol is the sole cause of heart disease. It does not matter, the fact remains that atherosclerosis occurs only in herbivores. If humans were physiological omnivores, heart disease would not exist, let alone be America's #1 killer for over a hundred years. It may not be the least bit hyperbolic to say that the existence of heart disease in humans is proof that we, as a species, are vegans. In any case, a low fat vegan diet has been proven again and again to be the cure for heart disease. A mountain of clinical evidence supports this. According to Roberts, those who are utterly immune to heart disease without the use of statin drugs are pure vegetarian fruit eaters. His own exact words. fruit eaters. So in addition to never losing an argument with a meat eater ever again, we can rest assured that according to America's top cardiologist, our diet of choice here at 30BaD ain't so crazy at all compared what the myriad of people pretending to be meat eaters are doing. |
Looks like a sound argument, right?
It really isn't!
The argument refuted
It isn't as simple as that. There are three facts which Dr Roberts appears not to have taken into consideration:
- The first fact is that herbivores do not have to be fed cholesterol-rich foods for them to develop atherosclerosis. Merely feeding them the wrong, usually starch- and sugar-rich, plant foods can cause cardiovascular disese.
- The second fact is that carnivores not only can develop atherosclerosis, they do — if they are fed carbohydrate-rich plant foods.
- And the third fact is that levels of blood cholesterol over 150 do not cause or increase the risk of heart disease or atherosclerosis.
I will look at each of these in turn. And, unlike the 30BaD website, I'll quote evidence to support my side of the debate.
1. Coronaries in herbivores
Dr Roberts is entirely correct when he says that only herbivores develop atherosclerosis — in laboratory conditions when the object of the exercise is to produce atherosclerosis and they are fed an inappropriate cholesterol and animal-fat diet. But that is not because cholesterol and animal fats are intrinsically harmful substances, but because they are inappropriate and alien in the diet of a herbivore.
Gorillas and other herbivorous primates in the wild and eating their natural diet never develop atherosclerosis. But captive animals are not fed what they would normally eatin the wild.. Dr Cousins, writing is 1976, tells us that "It is clear that most zoos feed their gorillas a principally frugivorous diet, while the diets of wild gorilla populations are undoubtedly basically herbivorous."1 Feeding a gorilla, for example on a high-starch, low fibre diet which, for a hindgut digester that breaks down dietary fibre to produce short-chain fatty acids, equates to a low-fat diet, they do suffer premature cardiovascular disease. And without any cholesterol or animal fat in their diets.2,3
2. Coronaries in carnivores
The same is true of carnivores. Dogs, cats, lions, etc, don't develop atherosclerosis when fed a cholesterol-rich diet simply because that is appropriate for them. But they suffer these conditions if fed starchy plants. Any vet can confirm that carnivorous pets and zoo animals develop atherosclerosis if fed plant- and grain-based pet food. In fact, heart attacks are almost as common in pet dogs as they are in their owners.4,5
The same is true of animals kept in captivity in zoos. Dr. Clarke Stout pointed out in 1969 that:
"the arterial lesions of animals are often quite similar to the early human proliferative atherosclerotic lesions. Since the arteries of most mammalian species (including man) resemble each other morphologically, it seems reasonable to assume that the finding of similar arterial lesions in different species might imply that similar pathogenic mechanisms had been operative in their production."
And it seems that the cause of the lesions is the same as in both us and our pets: starchy carbohydrate foods.
"Food thrown by the public was available to the large Carmivora and the seals and sea lions. Although the latter received primarily fish from public food dispensers installed for that purpose, the large Carnivora, and particularly the bears, were offered a variety of tidbits including peanuts, popcorn, candy, and other items."6
Dr Stout lists carnivorous animals in which atherosclerosic lesions have been found:
| Coyote | American Black bear | Sloth bear | Cacomistle | Raccoon |
| African civet | Spotted hyena | Fisher | Golden cat | Spotted cat |
| Weimeraner dog | Sealion | Harbor Seal |
Adding to the list of land and sea aniamls, Dr Emily P Lane published a list of carnivorous birds.7 This included:
| Eagles, | Hornbills, | Ratites, |
| Storks, | Herons, | Polar Penguins |
So, we now know that atherosclerosis can and does also affect carnivores. This fact destroys Dr Roberts' assertion that humans must be herbivores.
But what about his other assertion: that blood cholesterol over a certain level is a causative factor in cardiovascular disease?
3. Coronaries in humans
Although we have been taught for some decades that rising cholesterol levels increase the risk of atherosclerosis and a heart attack, there is very little actual evidence to support this hypothesis.
"The cholesterol hypothesis links cholesterol intake and blood levels to cardiovascular disease. It has had enormous impact on health care and society during decades, but has little or no scientific backing that is relevant for the human species."
So began a paper published in 2011.8
It pointed out that "The idea that cholesterol is dangerous took root with the well-known Framingham study9. It was found that the cholesterol level had been slightly increased after a heart attack in previously healthy men. Therefore, it was claimed that high cholesterol was a risk factor for myocardial infarction. Amazingly, very little attention was taken when the 30 years follow-up of the Framingham project was published 10. It turned out that high cholesterol was not a risk factor for men older than 47 years and not for women at all. Further, it was found that more men had died of a heart attack among those whose cholesterol had decreased over the years. The authors wrote :
"For every milligram percent cholesterol had decreased, cardiovascular mortality and total mortality increased by fourteen and eleven percent" .
Other studies have strongly supported this conclusion:
- Sachdeva and coworkers11 found that the cholesterol level in patients with acute myocardial infarction (heart attack) was substantially lower than in normal controls at the same age.
- Al-Mallah and coworkers12 found lower LDL values in patients with acute myocardial infarction and also that the mortality rate was twice as high among patients with the lowest LDL values."
Another very big and long-running study published in 200413 found that:
"higher saturated fat intake was associated with a smaller decline in mean minimal coronary diameter (P = 0.001) and less progression of coronary stenosis (P = 0.002) during follow-up. Compared with a 0.22-mm decline in the lowest quartile of intake, there was a 0.10-mm decline in the second quartile (P = 0.002), a 0.07-mm decline in the third quartile (P = 0.002), and no decline in the fourth quartile (P < 0.001); P for trend = 0.001."
In other words, the more saturated fat you eat, the less your arteries will get blocked! But as well as finding that saturated fat was not associated with atherosclerotic progression, it found that carbohydrate intake was, as were polyunsaturated vegetable oils when they were used to replace saturated fats. And these all come from plants!
According to NHLBI Director Dr. Claude Lenfant: "This study suggests that obesity is an important risk factor for heart failure in both women and men." High cholesterol is associated with obesity which in turn is associated with a carbohydrate-based, low-fat diet. "The people who ate the most saturated fat were the most healthy and had the lowest risk of heart disease."
These and other studies published in this last decade show clearly that there is no causal relationship between the cholesterol level in blood and the risk of dying from a heart attack. Or that saturated animal fats are in any way harmful.
Epidemiological studies
There are many human cultures around the world from the poles to the tropics that live entirely on animals, eat a high cholesterol, high animal-fat diet, but don't suffer heart attacks. There are others whose traditional diets are a mix of animal- and plant-sourced diets who also do not have heart attacks. It is only we who eat processed foods — which are predominantly based on cereals and processed vegetable oils who do. This strongly suggests that the inappropriate part of our diet is not the animal-sourced foods but the processed parts. And they are all from the cheap-to-produce plant world. It is the same with our carnivorous pets and captive carnivorous animals in zoos.
And that destroys Dr Roberts last argument.
But all of this study is really unnecessary because any serious examination of our gastrointestinal physiology shows that it is similar to that of the world's other carnivores and entirely unsuited to a herbivorous diet.
I realise that Dr Roberts would not agree with this statement. In his latest paper, he states "Although most of us conduct our lives as omnivores, in that we eat flesh as well as vegetables and fruits, human beings have characteristics of herbivores, not carnivores (2)." However, that is demonstrably untrue, which is probably why the reference he calls upon to support his assertion is his own 2000 paper!
Conclusion
Not one of Dr Roberts' arguments stands up to even the most cursory investigation: Dr Roberts' and other data simply do not support an argument that only herbivores get atherosclerosis; they also do not support his assertion that carnivores don't get atherosclerosis; they do not support the myth that raised cholesterol is the sole cause of atherosclerosis; and they do not support his contention that humans must be natural herbivores.
What they actually do demonstrate is that atherosclerosis and heart disease are confined to animals (herbivores, omnivores or carnivores) which eat plants. Which strongly suggests that, to avoid heart disease, we should not eat starchy and sugary plant foods or fruit!
Incidentally, how the people who run the 30 bananas a day website think that the whole human population could be maintained on 30 bananas a day each, when bananas can only be grown on a small proportion of the world's land, is beyond me. And that is besides the insurmountable problem that bananas, like all fruit, is seriously deficient in proteins and many essential fats and other nutrients.
References
1.Cousins D.A review of the diets of captive gorillas (Gorilla gorilla). Acta Zool Pathol Antverp 1976;66:91-100.
2. McGuire JT, et al. Plasma alpha-tocopherol, retinol, cholesterol, and mineral concentrations in captive gorillas. J Med Primatol 1989; 18:155-161;
3. Schmidt DA, et al. Cholesterol values in free-ranging gorillas (Gorilla gorilla gorilla and Gorilla beringei) and Bornean orangutans (Pongo pygmaeus). J Zoo Wildl Med. 2006 Sep ;37 (3):292-300
4. Jordan E, et al. Dyslipidemia in obese cats. Dom Animal Endocrinol 2008; 35: 290-299.
4. Kagawa Y et al. Systemic atherosclerosis in dogs: histopathological and immunohistochemical studies of atherosclerotic lesions. J Comp Pathol.1998;118:195-206.
6. Stout C. Atherosclerosis in Exotic Carnivora and Pinnipedia. Atheroslerosis 1969; 57: 673-87
7. Lane EP. Atherosclerosis in a Wahlberg's Eagle (Aquila wahlbergi) Research and Scientific Services, National Zoological Gardens of South Africa 05 March 2010 (www.nzg.ac.za/download/wdi_eagle.pdf)
8. Scherstén T, et al. The Cholesterol hypothesis: Time for the obituary? Scand Cardio J 2011; 45: 322-323.
9. Kannel WB. The role of cholesterol in coronary atherogenesis. Med Clin N Amer 1974;58:363-79.
10. Andersson KM, et al. Cholesterol and mortality. 30 years of follow-up from the Framingham study. JAMA 1987;257:2176-80.
11. Sachdeva A, et al. Lipid levels in patients hospitalized with coronary artery disease: An analysis of 136,905 hospitalizations in Get With the Guidelines. Am Heart J 2009;157:111-7
12. Al-Mallah M, et al. Low admission LDL-Cholesterol is associated with increased 2-years all-cause mortality in Patients with non ST segment elevation myocardial infarction. Cardio J 2009;16:227–33.
13. Knopp RH, Retzlaff BM. Saturated fat prevents coronary artery disease? An American paradox. Am J Clin Nutr 2004; 80: 1102-1103
Related Articles
