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  • Hi, this is Dr. Sofia Pineda Ochoa with Meat Your Future. Are humans

  • herbivores, carnivores or omnivores? It's very important for a given animal to eat what

  • they are physiologically and anatomically designed to eat, to improve the chances of

  • survival and health. So, what are humans designed to eat? When looking at a

  • species to determine what they are in terms of carnivore, omnivore or herbivore, we can

  • look at their behavior or we can look their biology. From a behavioral

  • standpoint, humans behave as omnivores because we observe many humans in their behavior eating

  • a wide variety of both animal and plant-based foods. Biologically, however, from

  • a physiologic and anatomic standpoint, it's a different story.

  • Dr. William C. Roberts from the National Institutes of Health and Baylor

  • Universitywho is the editor-in-chief of the American Journal of Cardiology and one

  • of the most prominent cardiologists in the world, with over 1,500 publications

  • in peer-reviewed medical journalssummarized our answer very nicely. He wrote:

  • Although most of conduct our lives as omnivores, in that we eat flesh

  • as well as vegetables and fruits, human beings have characteristics of

  • herbivores, not carnivores. The appendages of carnivores are claws; those of herbivores

  • are hands or hooves. The teeth of carnivores are sharp; those of herbivores are mainly flat (for grinding).

  • The intestinal tract of carnivores is short (3 times body length); that of herbivores is

  • long (12 times body length). Body cooling of carnivores is done by panting;

  • herbivores, by sweating. Carnivores drink

  • fluids by lapping; herbivores by sipping Carnivores produce their own vitamin C,

  • whereas herbivores obtain it from their diet

  • Thus, humans have characteristics of herbivores, not carnivores."

  • That's right.

  • Humans have characteristics of herbivores, not carnivores or omnivoresbecause omnivores,

  • like bears raccoons, actually retain most of the carnivorous

  • characteristics, so that they are still able to digest and hunt their prey, and do so

  • effectively. Although we behave like omnivores, our digestive system actually resembles

  • that of the chimpanzees and other great apes, who eat mostly plants. The percentage of

  • animal foods that chimpanzees do eat is very low, if any, about 2 to 3%

  • and mainly termites and other insects. Regarding the gastrointestinal system --

  • humans, like herbivores, have a relatively smaller opening of the oral cavity

  • compared to the head size. Carnivores have a wide mouth in relation to the head size, and their

  • jaw joint is a hinge joint, very strong and stable lying in the same plane as the teeth; the

  • lower jaw of a carnivore doesn't move forward and there's very limited side-to-side

  • motion. Like herbivores, our jaw joint is positioned above the level of the teeth, and because it

  • has an expanded angle, the lower jaw has more sideways motion and more lateral and

  • complex motion for chewing plant foods. Our jaw joints are less stable and strong

  • than those of carnivores therefore, and could be easily dislocated if we

  • actually tried to prey on an animal. On the other hand,

  • if a carnivore had our more unstable jaws, and dislocated their jaw, they would probably starve and die, or be preyed upon; so, it would be

  • very disadvantages to a carnivore to have jaws like ours. Herbivores chew food to disrupt

  • plant cell walls for better digestion and to mix it with saliva, because unlike carnivores,

  • who mostly swallow the food without chewing and mixing it with saliva, herbivores and humans

  • have saliva that contains digestive enzymes. So, our digestion starts in the chewing process.

  • The saliva of carnivorous animals does not contain any enzymes for digestion.

  • Teeth are strikingly different as well.

  • Our canines are flattened, blunt and small, shaped like a spade and non-serrated; unlike

  • carnivores, who have them elongated and dagger-like, which are often serrated for killing and

  • tearing their pray. Our molars and premolars are squared and flattened for grinding and crushing;

  • unlike carnivores, who have them sharp, jagged and shaped like a blade.

  • If we humans tried to kill a giraffe, for example, with our teeth,

  • we'd sooner get kicked by the animal. Or, if we successfully snuck-up and

  • actually tried to really bite into the live animal, it could could easily result in

  • some of our teeth falling out or our jaw dislocating. We would for sure end up

  • with a very annoyed giraffe, but not a dead one to prey upon. And on to the stomach. Our stomach

  • volume is, like herbivores, about 25% of our gastrointestinal tract; unlike carnivores,

  • who have a very large stomach volume with twice as much capacity, about 60 to

  • 70% of their total G.I. tract volume, which allows them to kill maybe once a

  • week, gorge on large amounts of meat, and digest later.

  • The pH of our stomach is about 4 to 5, with food;

  • unlike carnivores who secrete a lot more hydrochloric acid

  • and have a stomach pH that is a lot more acidic (their pH is usually one or less,

  • with food). The more acidic stomach of a carnivore is advantageous to kill bacteria found in

  • decaying flesh. As Dr. Roberts mentioned, humans, like herbivores, have a very long small intestine,

  • about 10 times the length of our body; unlike the intestines in carnivorous animals, which are

  • short, only about 3 to 5 times their body length. The long intestines in

  • humans and herbivores is necessary for the fibers in plants, which require

  • longer and more elaborate guts, sometimes even sacculated like the human gut.

  • And, there are some striking physiologic differences as well. Just like other herbivores,

  • humans require vitamin C from plants. If we don't eat vitamin C, we get a disease

  • called scurvy where we are unable to make collagen, which is

  • the building substance of mostly everything in our body (so, lack of vitamin C can

  • result in problems in our bones, bleeding gums, problems with healing, etc.).

  • And vitamin C is found exclusively in plants. Mammals that are primarily carnivorous do

  • not need to eat vitamin C from their diets. They make their own vitamin C. Also, vitamin A

  • is telling. There are two types of vitamin A: (1) preformed vitamin A, like retinol, found in animal

  • products like meat, liver, dairy products, eggs and fish; and (2) pro-vitamin A,

  • carotenoids, found in plant foods. The form of vitamin A that comes from

  • animals can be toxic to humans in large quantities. The livers of animals that

  • are primarily carnivorous have the capacity to detoxify vitamin A.

  • However, our livers are unable to do this. In this paper published in the American Journal of Clinical Nutrition,

  • scientists expressed concern that excess of the vitamin A that comes from animals is

  • not always identified and can cause serious problems. They say, “excessive

  • vitamin A intake may be a growing but underappreciated problem.” And apparently

  • this problem is nothing new. The scientists reported that: “Fossilized skeletal

  • remains of early humans suggest that bone abnormalities may

  • have been caused by hypervitaminosis A [which means excess of vitamin A]. From these

  • and other reports, vitamin A toxicity is known to be an ancient phenomenon.”

  • So, it looks like have been behavior omnivores for quite some time now, notwithstanding our biology.

  • The last thing I want to point out is actually a very sad thing. A characteristic that is unique to

  • herbivores and not in carnivores, and it's a problem in humans. It's something that

  • Dr. Roberts pointed out as well: “Atherosclerosis affects only herbivores.

  • Dogs, cats, tigers, and lions can be saturated with fat and cholesterol,

  • and atherosclerotic plaques do not develop.”

  • That's right. Carnivores and omnivoresanimals who are designed to eat other animalscan eat all the

  • animals and animal products they want and they never develop atherosclerosis,

  • which are plaques of cholesterol coating our vessels that can occlude the blood flow that goes

  • to our heart and brain [and] cause heart attacks and strokes. Cholesterol in our

  • diet is only present in animal products, and we don't need to consume any of it,

  • because our body synthesizes already all of the cholesterol that we need for all of our biologic needs.

  • Animals that are not designed to eat meat, like herbivores, including humans, do develop atherosclerosis. We do develop

  • this problematic coating of cholesterol in our arteries, and we do it big time. Atherosclerosis is ubiquitous on

  • a Western diet with animal products since very early in our lives. We really do end up

  • paying a price for behaving like omnivores, when we are biologically designed as herbivores.

  • Thanks you very much.

Hi, this is Dr. Sofia Pineda Ochoa with Meat Your Future. Are humans

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Are humans omnivores, carnivores or herbivores?

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    羊奶 posted on 2018/03/29
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