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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

University — who 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 journals —
summarized 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 omnivores — because 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 omnivores — animals who are designed to eat other animals — can 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.
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人類到底屬於雜食性、肉食性還是草食性動物? (Are humans omnivores, carnivores or herbivores?)

1798 分類 收藏
羊奶 發佈於 2018 年 3 月 29 日
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