Comparative Anatomy
Natural carnivores have the inherent anatomical equipment provided as their birthright with which to apprehend, capture, kill, and rend their quarry. Dogs have powerful jaws that inflict fatal wounds to their prey. Humans however, have no sharp claws for tearing; no sharply pointed fangs for slashing; nor are our eyes or olfactory senses well developed for hunting. Nor is the human body designed to run fast enough to capture prey. Humans cannot grab animals in their mouth as do dogs, coyotes, wolves, jackals, lions, tigers, or cats. We instead inflict more damage with our hands and brute strength. Humans do however, have marvelous fingers, thumbs, and limbs for reaching, climbing and grabbing. Our natural food gathering capacity is very similar to the chimpanzees. Fruitarians of the primate order also have revolving joints in their shoulder, wrist, and elbow joints that allow for free movement in all directions. Frugivores have soft pliable, sensitive hands and fingers with opposable thumbs and flat nails that are perfect for grasping and gathering fruit.
Regarding the extremities of the other species, herbivores possess hooves allowing them to walk easily about grassy plains, and carnivores possess sharp claws allowing them to violently attack their prey. Tree-dwellers and fruit-gatherers also have stereoscopic binocular vision that makes vision precise enough to ascertain the position of tree limbs and objects.
Another anatomical comparison among species in the animal kingdom involves the structure of the skin. All vegetarian animals have abundant sweat glands. In carnivores, their sweat glands are atrophied and inactive. They are exempt from profuse sweating in order to prevent a large fluid loss that would cause concentrated precipitation of nitrogenous wastes (from flesh-eating). This explains why meat-eaters suffer in hot weather while vegetarians remain relatively comfortable.
Comparative Digestive Physiology
Among the various species throughout nature, the length of their particular alimentary canals also differs greatly in relation to their natural food. The gut of the carnivore is 3-6 times the length of their body. They require a short, smooth, fast-acting gut since their natural flesh diet becomes quite toxic and cannot be retained within the intestine for long without poisonous putrefaction taking place. The gut of the herbivore is sacculated for greater surface area, and is 30 times the length of their body. Its herb and grass diet is coarse and fibrous, requiring longer digestion to break down cellulose. The length of the omnivore's alimentary canal is generally 6 times its body trunk size. The gut of the frugivore (like humans) is also sacculated and is 12 times the length of its body. The human digestive tract is about four times as long as the carnivores. The intestine of the carnivore is short and smooth in order to dissolve food rapidly and pass it quickly out of the system prior to the flesh putrefying. The human digestive tract is corrugated for the specific purpose of retaining food as long as possible until all nutriment has been extracted, which is the worst possible condition for the digestion and processing of flesh foods. Meat moves quickly through the carnivore's digestive tract and is quickly expelled. The human lengthy intestine cannot handle low-fiber foods including meat and dairy very quickly at all. As a consequence, animal foods decrease the motility of the human intestine and putrefaction almost invariably occurs (as evidenced by foul smelling stools and flatulence), resulting in the release of many poisonous by-products as the low-fiber food passes through, ever so slowly. In humans, eventual constipation may develop on a meat-centered diet. Colon cancer is also common, both of which are rare or non-existent on a high-fiber diet centered around raw fruits and vegetables.
Stomach, Kidney and Liver!
Stomach form and size among various species also vary markedly. In the carnivore the stomach is a small, round sack designed to dissolve flesh quickly and then pass it on for removal. In plant eaters (particularly ruminants) stomachs are complicated adjoining sacks with ring-like convolutions. The frugivore stomach (including humans) is oblong and is characterized by folds called rugae which serve to retain food for relatively long periods.
Organ sizes of various species also markedly vary. The liver and kidneys in the carnivore are much larger than in vegetarian animals. A lions kidney is twice the size of a bulls, and not much smaller than the elephants. This allows the lion to handle large amounts of protein and nitrogenous waste products contained in its natural flesh diet. The carnivores huge liver secretes larger amounts of bile into the small intestine than does the herbivores liver. There is a direct relation between the quantity of meat eaten and the amount of bile secreted. Meat-eating therefore, places a strain on the small liver of humans which impairs the organ's function over a long period of time.
When you place humans on a diet for which they are NOT naturally adapted, this places unnatural stress on the organs of elimination. Humans have never adapted to the carnivorous diet that is high in animal products. The human liver is smaller than the carnivores and as a result, we cannot detoxify the poisonous products inherent within animal foods such as uric acid (discussed below). Our kidneys are also smaller and become diseased from overwork caused by a diet high in animal protein.
Comparative Digestive Enzymes
The hydrochloric acid concentrations of various species are an additional determinant of their natural diet. A carnivores gastric juice is highly acidic, serving to prevent putrefaction while flesh undergoes digestion. Plant-eaters however, secrete a much less concentrated and less abundant quantity of hydrochloric acid that does not curtail the bacterial decomposition of flesh: a process that begins at the animals moment of death. Flesh is digested in an acid medium within the stomach. Humans secrete a very weak concentration of hydrochloric acid relative to the carnivore, and little of the protein-splitting enzyme pepsinogen. Carnivorous animals have concentrations of these flesh-digesting secretions 1100% greater than do humans. Lions can rip off and swallow your hand whole and quite readily digest it.
Uric Acid: Toxic Component of Meat to Humans
About 5% of the flesh volume of all animals consists of waste material called uric acid that is normally eliminated by the kidneys. Uric acid is a poison to humans because it is toxic and non-metabolizable. Nearly 100% of Americans suffer some form of osteoporosis which is due in large part, to the acidic end-products of meat (and grain) eating. All carnivorous animals however, secrete the enzyme uricase that breaks down uric acid so it can be readily eliminated. Humans do not generate this enzyme. Instead, we ABSORB uric acid when meat is eaten. As a result, calcium-urate crystals form and concentrate in joints, feet, and in the lower back. These deposits lead to arthritis, gout, rheumatism, bursitis, and lower back pain. Humans are physiologically unsuited to utilizing meat as food. Natural carnivores swallow hunks of carrion almost unchewed, and the flesh is digested in the stomach with ease and facility. If humans were to do the same, we would digest very little of it before putrefaction set in and illness ensued. For humans, meat is a pathogenic and nutritionally deficient food.
Saliva pH Varies Widely Among Species
The saliva pH of various species is another determinant of their natural diet. In carnivores, their saliva glands are small and secrete an acidic saliva having little or no effect on starch, which makes sense since flesh is virtually starch-free. Omnivores (like pigs) have tremendous salivary glands that secrete copious quantities of starch-splitting enzymes. Humans only have one starch-splitting enzyme, versus a multitude of them in omnivores and other natural starch-eating animals. Our ptyalin is very limited. This rules us out as being true granivores (starch-eaters) which includes grains and cereals. Frugivores have salivary glands that secrete alkaline saliva, containing only moderate amounts of ptyalin, which initiates starch digestion. This tells us that humans and other frugivores can easily digest the small amount of starch contained in fresh fruits, nuts, and leafy greens, and that humans are not intended to subsist on a diet of highly starchy grain foods as many currently do. (Diabetes mellitus is largely the result of consuming large amounts of refined sugars and starches. Even eating predominantly of whole grains and natural legumes as dietary staples can be injurious because of the need for excessive starch digestion).
Science Verifies That Human Ancestors Were Frugivores
Dr. Alan Walker, an anthropologist of John Hopkins University in Maryland , has done research showing that early humans were once exclusively fruit eaters. By careful examination of fossil teeth and fossilized human remains with electron microscopes and other sophisticated tools, Dr. Walker and his colleagues are absolutely certain that early humans until relatively recently, were total fruitarians. Source: New York Time, May 15, 1979.
"The natural food of man, judging from his structure, appears to consist principally of the fruits, roots, and other succulent parts of vegetables. His hands afford every facility for gathering them; his short but moderately strong jaws on the other hand, and his canines being equal only in length to the other teeth, together with his tuberculated molars on the other, would scarcely permit him either to masticate herbage, or to devour flesh, were these condiments not previously prepared by cooking."
-- Georges Cuvier (1769-1832), Regne Animal, Vol 1, p73
In conclusion, our natural diet should consist primarily of fruits, nuts, and green vegetables. We can be called frugivores because many "vegetables" are botanically considered fruits.
Frugivores are physiologically equipped to obtain energy primarily from the natural sugar in fruits. Humans are bestowed with a kind of "natural sweet tooth" to guide us in the selection of foods that meet our biological disposition and our caloric needs: namely, sweet juicy fruits. Our anatomy is such that we are capable of picking fruits, masticate, digest, and appropriate them with ease and efficiency. Fruits contain all the nutrients we need: vitamins, minerals, proteins (in the form of amino acids), fats, and carbohydrates. All seed-bearing foods are botanically defined as "fruit". This includes avocado, sweet pepper, cucumber, tomato, eggplant, even nuts and seeds.
In Botany fruit is mature ovary, and is made of two parts: the pericarp or edible flesh, and the seed portion itself from fertilized ovules.
