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Are We Natural Vegetarians?
A cat or dog salivates with anticipated pleasure at the
sight and smell of raw meat, but very few humans exhibit this behaviour. For most meat eaters, their chosen
cut needs to be cooked before it becomes attractive. This is just one factor that might make us wonder
whether eating meat is natural for us, and whether being a vegetarian is a realistic option.
Other clues can be found by comparing the anatomy and physiology of humans with different types of animal. It
emerges that humans are far more similar to fruit and nut eating animals - vegetariaqns such as monkeys and
apes, and to leaf and grass eating animals such as sheep, cattle, elephants and koala bears, than to the
carnivores.
The following two lists show the characteristics, first of carnivores, and then of non-carnivores, or
vegetarians.
Carnivores generally:
1. Have very short digestive tracts (three times their body length) to excrete decaying meat waste rapidly.
2. Produce very strong stomach acid - typically 20 times stronger than that of a non-carnivore - to digest bone,
sinews and large quantities of meat.
3. Produce small amounts of saliva because digestion does
not begin in the mouth with carnivores.
4. Tend to have jaws that can only move up and down, which means that they cannot grind their food and can hardly
chew at all. Meat is torn off with their long, sharp incisors and canine teeth, and is swallowed in large chunks.
The teeth are also shaped and angled to move with a shearing motion to cut through bone and tough sinews.
5. Show great agility in catching prey, and have sharp claws and strong jaws to bring down, kill and consume
prey.
However, vegetarians - non-carnivorous animals and humans generally:
1. Have long digestive tracts that are about the same proportion to body length as in grass-eating animals (12
times). The great length allows the longer period of time that is needed for fruit and vegetables to be digested
completely.
2. Have weak stomach acid, which is all that is necessary for the slow digestion of grasses, grains and vegetable
matter.
3. Produce a larger quantity of saliva, which also contains the enzyme ptyalin. The plentiful saliva and the
ptyalin begin the digestion of grains, fruit and vegetables in the mouth. Carnivores neither eat these kinds of
food nor do they chew their food, which means that digestive enzymes in their saliva are absent.
4. Have jaws that move with a grinding motion. This grinding together of the relatively flat teeth reduces the
particle size of the food and exposes it to the saliva and ptyalin in the mouth. Human canine and incisor teeth are
small compared to those of a carnivore and are, perhaps, better suited to biting tough vegetables rather than
animal skin and bone.
5. Have no claws, relatively weak jaws and not a great deal of agility. For example, if a chicken is placed in an
open space it would be extremely difficult for a human to catch it; we don't appear to be designed for that sort of
activity.
The evidence seems clear that humans have evolved to eat little or no meat - to be vegetarian.
Is Meat Actually Harmful?
Many people eat meat and appear to survive reasonably
well. So why shouldn't humans eat meat if they want to? Why should they be vegetarian? There is the moral
objection that animals should not be killed for the benefit of humans. This argument is complex because, for
example, few people go so far as avoiding shoes and gloves made from leather - and most of the arguments that
apply to leather also apply to meat. However, leaving the moral argument aside, there is a very strong reason
not to eat meat - it is bad for our health.
[Next: Meat Makes Disease More Likely]
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