Humans are naturally plant-eaters
The most common counter-arguments
"Humans have canine teeth. End of story."
The truth is our so-called "canine teeth" are canine in name only. Humans' "canine teeth" are unlike the canine teeth of actual canines, which are really long and really pointed. Our teeth are absolutely not like theirs. In fact, other vegetarian animals (like gorillas, horses, hippos, and chimpanzees) possess the same so-called "canine" teeth, which are often used for defensive purposes rather than for eating. Check out the chimpanzee picture at right, and consider that chimps' diets are up to 99% vegetarian (and what litle non-vegetarian food they eat usually isn't meat, it's termites). And remember that we're most similar to chimps than to any other animal.
John A. McDougall, M.D., has a good take on this:
Our dentition evolved for processing starches, fruits, and vegetables, not tearing and masticating flesh. Our oft-cited "canine" teeth are not at all comparable to the sharp teeth of true carnivores. I lecture to over 10,000 dentists, dental hygienists, and oral specialists every year, and I always ask them to show me the “canine” teeth in a person’s mouth – those that resemble a cat’s or dog’s teeth – I am still waiting to be shown the first example of a sharply pointed canine tooth.
If you have any doubt of the truth of this observation then go look in the mirror right now – you may have learned to call your 4 corner front teeth, “canine teeth” – but in no way do they resemble the sharp, jagged, blades of a true carnivore – your corner teeth are short, blunted, and flat on top (or slightly rounded at most). Nor do they ever function in the manner of true canine teeth. Have you ever observed someone purposely favoring these teeth while tearing off a piece of steak or chewing it? Nor have I. The lower jaw of a meat-eating animal has very little side-to-side motion – it is fixed to open and close, which adds strength and stability to its powerful bite. Like other plant-eating animals our jaw can move forwards and backwards, and side-to-side, as well as open and close, for biting off pieces of plant matter, and then grinding them into smaller pieces with our flat molars.
I love the canine argument because the people who make it place so much importance on it, insisting that humans having canines immediately wins the whole argument, all by itself, case closed! But when they discover that they were wrong, then suddenly the canine issue really wasn't so important to them after all, and they simply move on to their next misconception, as though their previous argument never happened. That really lays their motivations bare: They were never really interested in evaluating the evidence, they were only interested in being right. But really, if someone thinks that canine teeth are the be-all and end-all of the herbivore vs. omnivore debate, then when they find out that they're wrong about teeth, that ought to tell them something. But does it ever? Nope. If you want an evidence of bias, there you have it.
"Humans have always eaten meat."
No, we haven't. Just because we assume that humans have always eaten meat doesn't make it true. I'll provide evidence for this shortly. But what's more important is that unlike other animals, humans can act outside of instinct. That means that if early humans did eat meat, they were simply making an interesting choice, not doing what their biology favors. We really have to look at our digestive system to get the best evidence for what we're optimized for eating, not what some humans chose to eat. Otherwise, thousands of years from now anthropologists might conclude that eating McDonald's is natural because humans circa 2011 used to eat a lot of it.
I'll cover the early human diet in more detail momentarily.
"We're capable of eating meat, therefore we're omnivores. Case closed."
Okay, fine, then cats are omnivores, too. ("Case closed.") Commercial cat foods, both wet and dry, contain things like rice, corn, and wheat. In fact, some people feed their cats a pure vegan diet with no meat at all.
But of course, cats are true carnivores. We don't call them omnivores just because they'll eat things contrary to what nature intended. That would be silly. No one makes that argument for cats. But they make it for humans, enthusiastically. However, they can't have it both ways: Either we don't assume humans are omnivores just because we can eat meat, or we apply the same standard to other animals and conclude that cats are omnivores, too. Which is it?
"Humans are omnivores."
Then what exactly is an omnivore? If it's an animal that is capable of eating both plants and animals, and ever does so, then sure, we're omnivores, but then again, so are cats. (See above.) A true omnivore would have a body optimized for eating both plants and animals. With non-humans we can look at what they eat in the wild to figure out their preferred diets, but humans lost our instincts long ago, so we can look only at our anatomy and digestive systems. And that evidence is compelling. I'll cover the omnivore issue in more detail below.
"You're not a doctor, therefore you must be wrong. Yay, I win!"
It's funny, the people making this charge aren't doctors either, but somehow they don't feel that being a doctor is neccessary to advance their positions.
In any event, bona-fide doctors say the same kinds of things I say in this article. For example, here's an article by Dr. John McDougall and one by Dr. Milton R. Mills (both M.D.'s). I wonder whether the people who send me hate mail about this article and tell me I'm an idiot would feel just as confident in telling these two doctors that the doctors are idiots, too?
"Vitamin B12. End of story."
I'm not joking when I tack on "End of story" to the sample counter-arguments. People actually make them that way, literally.
B12 isn't made by animals, it's made by bacteria. (source) It's found where things are unclean. (And meat is dirty.) This easily explains why historically it's been easy to get B12, because until recently we didn't live in a sanitized environment. Plants pulled from the ground and not washed scrupulously have B12 from the surrounding soil. (source) Vegans should take a B12 supplement, not because veganism is unnatural, but because the modern diet is too clean to contain reliable natural sources of dirty B12.
B12 is also found in lakes, before the water is sanitized. (source) Also, consider that chimpanzees' main non-plant food is termites, and termites are loaded with B12. (source)
Incidentally, our need for B12 is tiny -- 3 micrograms a day. Not milligrams, micrograms. The amount of B12 you need for your entire life is smaller than four grains of rice. (More on Vitamin B12 from John McDougall, M.D)
"Other primates eat meat."
Hardly. Various sources (below) say that a chimp's diet is 95-99% plant foods, and the primary non-plant food isn't meat, it's termites. We also have to remember that primates are intelligent and can make choices outside of instinct, just like humans do, so the tiny amount of meat they might eat could simply be due to choice, not instinct. The idea that primates are a good example for why humans should eat meat evidently didn't impress the most famous primate researcher of all time, Jane Goodall. Goodall is a vegetarian.
I cover the primate diet in more detail bolew.
"You're not considering evolution."
Of course I'm not. Humans' hunting skills are relatively recent in our history but evolution takes place over a much longer period of time. In short, we haven't been hunting for long enough for our anatomy to favor a mixed plant-animal diet.
But haven't humans always eaten meat?
In a word, no, which we'll discuss in a moment, but first there's something more important: Even if they did, it doesn't matter. That's because people act by idea rather than by instinct. Other animals are programmed to know what food is. We are not. For us, it's learned behavior. Or in some cases, guessed behavior. We can make choices about what we should eat even if that's contrary to good health, as millions prove every day when they eat at McDonald's. If our ancestors ate meat, they were simply being human and making choices rather than acting on instinct. Think about it: Do you really believe that cavemen were true experts about nutrition? If so, what other major decisions about your life would you like to put in the hands of a caveman?
Again, the best evidence is to look at our own bodies. But let's return to the assumption that our ancestors ate meat. I can't think of a better example of a case in which people believe something to be true just because they assume it is. We all grew up thinking that our predecessors were meat-eaters, but where did we get that idea? Is it true just because it's part of our collective consciousness? More importantly, what does the evidence say?
John A. McDougall, M.D., perhaps the most knowledgable expert on the relationship between diet and disease, asserts that our early ancestors from at least four million years ago followed diets almost exclusively of plant foods. (source, article #5) Many other scientists believe that early humans were largely vegetarian. (See articles by Grande & Leckie and Derek Wall.) Then there's the newest research:
Robert W. Sussman, Ph.D., professor anthropology in Arts & Sciences, spoke at a press briefing, "Early Humans on the Menu," during the American Association for the Advancement of the Science's Annual Meeting....[E]arly man was not an aggressive killer, Sussman argues. He poses a new theory, based on the fossil record and living primate species, that primates have been prey for millions of years, a fact that greatly influenced the evolution of early man.
"Our intelligence, cooperation and many other features we have as modern humans developed from our attempts to out-smart the predator," says Sussman.... The idea of "Man the Hunter" is the generally accepted paradigm of human evolution, says Sussman, "It developed from a basic Judeo-Christian ideology of man being inherently evil, aggressive and a natural killer. In fact, when you really examine the fossil and living non-human primate evidence, that is just not the case."
Sussman's research is based on studying the fossil evidence dating back nearly seven million years. "Most theories on Man the Hunter fail to incorporate this key fossil evidence," Sussman says. "We wanted evidence, not just theory. We thoroughly examined literature available on the skulls, bones, footprints and on environmental evidence, both of our hominid ancestors and the predators that coexisted with them." ...
But what Sussman and Hart discovered is that Australopithecus afarensis was not dentally pre-adapted to eat meat. "It didn't have the sharp shearing blades necessary to retain and cut such foods," Sussman says. "These early humans simply couldn't eat meat. If they couldn't eat meat, why would they hunt?"
It was not possible for early humans to consume a large amount of meat until fire was controlled and cooking was possible. Sussman points out that the first tools didn't appear until two million years ago. And there wasn't good evidence of fire until after 800,000 years ago.
While some prehistoric peoples hunted animals, that is still a relatively recent development in the long period of human existence. Certainly not long enough for our bodies to have adapted to it from evolution. Here's some evidence: The Maasai in Kenya, who still eat a diet high in wild hunted meats, have the worst life expectancy in the world. (Fuhrman)
In any event, the idea that our ancestors might have decided to mimic other animals and eat meat isn't a particularly compelling argument that it's natural for us to do so. Given that humans act outside of instinct, looking at historical behavior isn't as convincing as looking at anatomy and health effects -- as we'll do in a moment.
Read full article here: http://michaelbluejay.com/veg/natural.html