I stumbled upon this image on twitter of someone trying to argue against eating meat. This image claims that humans are biologically herbivorous. Here’s the list, let’s check it out!
Ok, that’s quite an extensive list of comparative physiology.
Stomach acidity of herbivores
This one instantly stuck out to me, so I’m gonna address it first. Human stomach acidity is not 4-5, that’s wrong. Multiple sources consider human stomach acid to have a pH of 1.5, which means we are close to the stomach acidity of carrion-eating scavengers like vultures. This is thought to be the result of early hominid species living as scavengers for a period of time. The high acidity is needed to protect against pathogens that could be present in carrion.
In fact, if your stomach acid were pH 4-5 as this list suggests, you would be suffering from hypochlorhydria. This condition is often mistreated by giving people PPIs (Proton-Pump inhibitors) or similar medication, that interferes with stomach acid production even further and actually worsens the underlying problem. PPIs are not even supposed to be taken longer than 3 weeks, and yet many people have been prescribed them for years. In the long run, hypochlorhydria will leave you susceptible to SIBO, gastrointestinal distress, Vitamin B12 deficiency, iron deficiency anemia, vitamin deficiency anemia, osteoporosis and H. Pylori infection.
It’s debunked within 3 seconds of searching. Do I even need to look at the rest of this list? Yes? Ok…
Jaw & Teeth of herbivores
The claims in the list regarding our jaws and teeth are mostly correct. The only thing I’d argue against is the idea that our jaws have good side-to-side and front-to-back motion. This only holds true if you are not actually biting down, but of course you have to bite down in order to actually chew the food. If you clamp your teeth shut, almost no motion is possible. I’ve also never actually observed a human utilizing these motions in any major way for chewing, at least not compared to how pronounced it is in cows or camels.
Either way, it is an irrelevant point since the status of “carnivore” is not determined by the shape of your teeth, or placement of your muscles or any of that. Otherwise, we have to tell all whales that they are doing it wrong, since they don’t even have any teeth at all, neither do they have claws. Somehow, whales are carnivores regardless. Leeches also have quite different feeding habits, physiology and biology and are still carnivores.
Other claims about human herbivory
Our saliva contains carbohydrate digesting enzymes, amylase to be specific. Again, that is true, but also irrelevant. The presence of amylase does not mean we are not carnivores. It simply hints at a distant past, where early humans were indeed herbivorous. Emphasis on “were”. Unless there is an evolutionary benefit to getting rid of this enzyme, evolution will not select against it. In the case of amylase, there probably was even a benefit of keeping it, since it allows us to (easier) fall back to starches if the circumstances requires it.
In a similar vein, that’s why humans also don’t have sharp teeth and claws. Instead, we invented weapons and tools. There is no need to evolve sharp teeth if we can simply shoot an animal with bow & arrow, tear it apart using knives and chew it up perfectly fine with our existing type of teeth. I don’t know about you, but I never struggled to chew my steaks.
And again the same goes for our digestive tracts. They are perfectly adequate to digest meat and fat, there was no need for any major structural changes. Apart from the cecum of course. The size of the cecum is biggest in herbivores, smaller in omnivores, and tiny or non-existent in carnivores. The human cecum has a tiny size of 5-7cm, whereas a horses’ cecum can contain up to 38 liters of material. The cecum is used to ferment fibrous plant material, which explains why it is biggest in herbivores. In human digestion it absorbs salts and electrolytes and lubricates waste material that enters the colon.
Conclusion
I’m sorry, but this list does nothing to convince me that humans are herbivorous. Apart from one glaring mistake (and I’m assuming it is not intentionally wrong), none of the other arguments are relevant. Carnivores come in very different shapes and sizes, so claiming humans are herbivores because we don’t have sharp teeth and claws is ridiculous.
What matters more here is, in my humble opinion, the anthropological evidence of what humans actually did consume for millions of years and hence are genetically adapted to. I shall post about that in the future but spoiler alert: It was heavy on meat and very little plants on the side.
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