Are humans carnivores, herbivores, or omnivores? A lot of people are quick to state ‘omnivores’ but is that really true? A lot of people worldwide are under the impression that humans have been misclassified as omnivores for various reasons. Though I could write a very long article about our anatomy, biology, instincts, characteristics, and disgust reflexes, I am only going to focus on teeth, jaws, and chewing in this article. Chances are, you are an intelligent being with rational thought (or you wouldn’t be here on this site asking questions) and therefore, you have an innate ability to seek out answers on your own. So based upon the evidence about to be presented, for the moment, forget what you think you know and think about this issue from an objective standpoint.
Looking at our jaw, this is probably the biggest giveaway that humans are plant eaters (source). Our teeth are built for chewing (chewing is an herbivorous trait). We have broad, short, blunt, and flat teeth just like the teeth of other herbivores, namely hominids, (source) that slide across each other horizontally to provide for the mechanics of grinding. This is very efficient for grinding plant foods. We have strong facial muscles which allow us to move our food around in our mouth in order to chew it. We use the combination of our tongue, cheeks, lips, and teeth (side-to-side grinding) to assist our chewing, which is done in a round, circular motion. This is the same as other herbivores. Furthermore, this well-developed facial musculature al
lows us to create a vacuum with our lips in order to suck water from a source. As for canines, most herbivores have canines (such as a gorilla) and use those teeth to either scare predators away or eat hard fruit like apples or nuts. Don’t believe me? The next time you find a Pistachio nut that is “unopenable,” try cracking it with your canines. Because our canines are utterly useless at ripping and tearing anything, they are reduced in size when compared to anatomical carnivores or omnivores and function essentially as accessory incisors. As is expected from the shape of the teeth and jaw, the diet of non-human hominids, aside from insects, is entirely plant foods.
Contrarily, omnivores have very limited side-to-side mobility. Their jaw is on the same plane as their molars, unlike humans which have an L-shaped jaw with the jaw muscle located above the plane of the teeth. Omnivores are also unable to create a vacuum with their lips and mouth to drink water, and so, they resort to lapping up their water with their tongue just like carnivores. The picture on the right is a grizzly bear.
As for carnivores, the jaw is on the same plane as their teeth allowing for a more stable jaw joint (a hinge joint). Their jaws cannot go side to side because they do not chew (source). The reasoning for their jaws only moving up and down is clear when one considers that the jaw of an anatomical carnivore and omnivore must be strong enough to wrestle an animal to the ground and in most cases, end the animal’s life while it’s struggling to free itself. If we tried to wrestle an animal to the ground, the animals would surely dislocate our weak jaws, (source). Like anatomical omnivores, carnivores rip and tear out flesh and swallow it essentially whole (source). The shape and function of a carnivore’s teeth are to act like a pair of scissors or shears. Even the molars in the back are angled in a way to slice through flesh. Carnivores have reduced facial muscles and like omnivores, cannot create a vacuum with their lips and mouth in order to suck water out of a source. Although, an interesting note about carnivorous mammals is that when they are babies, their faces are born in such a way that allows them to create a vacuum and suckle their mother’s teat for nourishment. However, as they grow older, they lose the ability to create a vacuum and must resort to lapping up their water when they’re weaned off of milk.
Finally, we humans have carbohydrate digestive enzymes in our saliva (only herbivores have that). The saliva enzyme in question is called “Salivary Amylase,” though it should also be noted that we have pancreatic amylase as well which helps to facilitate the breaking down of plant-based foods for digestion. “Amylase is an enzyme that breaks down carbohydrates and is only found in those animals that consume significant amounts of carbohydrate in their diets,” says specialist of internal medicine Dr. Milton Mills. “The purpose of ‘chewing’ is to mix
digestive enzymes with food to begin the process of digestion. For instance, you may or may not know that mammals do NOT make any enzymes that can break down (digest) cellulose—but bacteria and protozoa do. This is why some herbivores (ruminants) that eat a high cellulose diet have to have multiple stomachs. Their first stomach contains a bacterial soup that releases cellulose digesting enzymes. So the ruminants first crop and swallow a stomach full of grass/hay/etc., and then allow ‘the swallowed material’ to soak up the bacterial enzymes. They then bring this mixture back up and “chew the cud” to shred the grasses and thoroughly mix the enzymes with the ingested material. They then re-swallow the chewed grass/enzyme mixture and it goes into a different stomach to allow the enzymes to breakdown the cellulose into its constituent glucose molecules that can then be absorbed in the small intestine. As for carnivores, and anatomical omnivores,” Mills continues, “they DO NOT CHEW! This is because there are NO enzymes in their saliva and thus, there is no need to chew. They simply slice off hunks/chunks of meat, bone, and hide, and allow their strong stomach acid and pancreatic enzymes to digest their food.” The reason these animals don’t need to chew is because their throats are considerably wider than ours. You can verify this if you’ve ever choked while eating. If we don’t chew our food before swallowing we could choke and die. This is another reason for saliva mixing with our food for the purpose of lubricating it before swallowing.
In conclusion, thanks to the wealth of information now available to people and the newly introduced studies which seem to come out yearly, the surprising question many people are beginning to ask themselves is: are humans designed to eat meat? Are we omnivorous? The answer to this question may be in the words of Thomas Paine: “A long habit of not thinking a thing wrong, gives it a superficial appearance of being right, and raises at first a formidable outcry in defense of custom. But the tumult soon subsides. Time makes more converts than reason,” (source). When one considers that many of our diseases (more than 68%) are on the rise due to a whole species overeating a material that is anatomically not part of their natural diet, the shocking health statistics put forth by the world’s leading research teams are not hard to come to terms with (World Health Statistics) (US Surgeon General’s Report on Diet and Nutrition) (Top 10 Causes of Death) (World Health Statistics 2014) (World Health Statistics 2014 2) (Obesity) (Cancer) (70% of US on Prescription Drugs) (CDC on US Prescription Drugs) (CDC on Cholesterol) etc.
- A special thanks to Dr. Milton Mills for his feedback, contributions, and willingness to help me in writing this article. Dr. Mills is a frequent lecturer (Are Humans Designed To Eat Meat?, Meat Eating and the Biology of the Disgust, Treating and Curing Diabetes with Diet and Nutrition,) and author of a short essay entitled “A Comparative Anatomy of Eating.
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