Evolution has played a role in the vegan/vegetarian argument for many years. Often people will talk about incisors and their role in meat eating or whether or not humans still have the hunter/gatherer instinct.
Recently, new research has indicated that meat might have played a more important role in our evolutionary make up than originally thought as some scientists believe that it was eating meat that allowed our brains to grow beyond the brains of most other mammals. In essence, eating meat is what made us ‘human’.
This new research has been used by some to back up the argument that a vegan or vegetarian diet isn’t ‘natural’. But is there any merit to this assertion?
When compared to other mammals, human beings have much bigger brains in comparison to the size of their bodies. Scientists are now attributing this to the calories we consumed by eating meat. These claims come after the skull of an infant was found dating back around 2 million years. It was concluded that the infant had died from ‘porotic hyperostosis’ which usually occurs from a lack of vitamin B9 and B12. Given that the infant was under 2 years old it can be assumed that it was either still feeding from it’s mother or it was being weaned onto solid food.
If the human body was not set up to expect B9 and B12 in order for it to function properly then it would not be possible for an infant to die of a deficiency of said vitamins. Scientist concluded that because B12 doesn’t exist in fruit, vegetables, legumes or grains, our ancestors must have been consuming meat.
Vitamin B12 is a highly contentious subject when discussing veganism due to the fact that humans are not capable of making B12 within the body and therefore must procure it from outside sources. B12 is synthesised by bacteria and as such it exists only in areas of bacterial growth. This includes animal guts, which is why animal protein contains B12, but it can also be created in dirt and soil.
The reason that vegans have to take B12 supplements is because on the whole humans no longer consume dirt and soil, but instead we wash our fruit and vegetables rigorously. This is necessary for the most part given that animal manure is used to grow produce and many different pesticides are now used in the farming process that are bad for our bodies.
However, our ancestors were likely to have consumed B12 from eating vegetables grown in the soil. They wouldn’t have taken the veggies home to wash under the kitchen sink and dirt and soil would still be present on what they were consuming. In addition to this, B9 is very prevalent in plants. Humans require only 200 μg of vitamin B9 a day to maintain a healthy, functioning body. This is present in a single cup of cooked beans, a cup of cooked lentils, 4 cups of raw spinach or a cup of asparagus. In other words if you’re eating a whole food plant based diet it would be very difficult to not keep up with your vitamin B9 intake.
In addition to this, it is widely accepted that many of our ancestors, did in fact eat a vegetarian diet and continued to evolve through this way of eating. Suggestions have been made that while meat eating may have played a role, it is more likely that carbohydrates were the nutrient which fuelled our brain growth. Neurons run on glucose, not meat.
However whilst it is possible that our ancestors could eat B9 and B12 on a plant-based diet, it doesn’t prove that they weren’t eating meat when our brains evolved. Although it does suggest that with the information we have we cannot be fully conclusive on the fact that the consumption of meat caused our brain growth either. Furthermore it has even been suggested that just the mere caloric density of meat (as opposed to it having magical properties ‘not found in plants’) was a factor in our survival. When plants were scarce, eating animals became humanity’s only food option, but this certainly isn’t a problem the Western world faces today.
What we can conclude is that the consumption of meat and dairy is hurting the human body in it’s current evolutionary stage. Perhaps rather than trying to prove that veganism isn’t ‘natural’ we should focus on that.