The most common arguments that meat eaters use.
"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. 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. 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. Also, consider that chimpanzees' main non-plant food is termites, and termites are loaded with B12.
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.
Human performance on meat-free diets
Not only do vegetarians and vegans easily build muscle, they often excel as athletes too, winning Olympic gold medals and world championships. In fact, some of the most famous bodybuilders in history were vegetarian. Here's a short list of vegan and vegetarian athletes.
Kenneth G. Williams (bodybuilder) 3rd place at 2004 Natural Olympia
Bill Mannetti (powerlifter) 1st place, Connecticut State Powerlifting Championship
Robert Cheeke (bodybuilder)
Joy Bush (powerlifter) 1st place, Connecticut State Powerlifting Championship
Jon Hinds (bodybuilder, personal trainer)
Charlie Abel (bodybuilder)
Mike Mahler (strength coach) ""Becoming a vegan had a profound effect on my training. … [M]y bench press excelled past 315 pounds...and I put on 10 pounds of lean muscle in a few months."
Mac Danzig (martial arts) MMA record 19-7-1 (as of 4-2010)
Tony Gonzalez (Atlanta Falcons tight end)
Scott Jurek (ultramarathoner) 7 consecutive wins at Western States 100 Mile Endurance Run, numerous other first place finishes and records
Tim VanOrden (runner) Numerous 1st place finishes
Fiona Oakes (runner) 1st place woman and 2nd overall in a 2011 marathon
Ruth Heidrich, (triathlete and marathoner) More than 900 first-place trophies and set several performance records. Named One of the 10 Fittest Women in North America.
Dave Scott (triathlete) Six-time Ironman champion
Brendan Brazier (triathlete). Won the National 50km Ultra Marathon Championships
Carl Lewis (track) Numerous gold medals (2 as a vegan)
Salim Stoudamire (basketball). Atlanta Hawks
Christine Vardaros (cycling)
Bill Pearl (bodybuilder) Mr. Universe (3 times), World's Best Built Man, Mr. America, Mr. California, numerous Halls of Fame
Roy Hilligenn (bodybuilder) Mr. South Africa (4x), Mr. America, Olympic lifter
Ricky Williams (football) Miami Dolphins
The research on veg vs. non-veg athletes is fairly sparse, but what does exist has failed to show any clear performance benefit for meat-eaters. (See my separate article, Protein and Strength.)