Questions about vegans

Yes.

Really?

I'm surprised. What did wine makers do in regions far from the sea in the past?

Surely fish protein is not a component of every wine.

 

As a theoretical question, the answer is yes. But in practice, it's very difficult. In fact we have only been able to even understand the underlying issues, much less deal with them, in the last hundred years since we developed biochemistry. Before that it was sheer luck if a population stumbled into a healthy, balanced diet that was not meat-intensive.

And many did not. Remember that the ancestors of Homo sapiens branched off from the chimpanzees a few million years ago, and we have spent all of that time turning into predators: the only truly carnivorous ape. The other primates supplement their diet with invertebrates and the occasional hapless small mammal or reptile, but their digestive system is tuned to extract most of its nutrients from plant tissue. Humans have completely lost the ability to digest cellulose: we don't have intestines the length of a railroad filled with a rich, stinky bacterial culture that converts plant tissue into protein and other building blocks of life, like cows and other herbivores have, and even to a certain extent chimps and gorillas, who can happily eat and digest leaves.

Everything about us... from our precise binocular vision, to our impressive canine teeth, to our bipedal posture that allows us to run upright and see over the grass, to our brains that invented spears, to our streamlined digestive system that requires us to eat protein... has been adapted to make us hunters, not grazers.

Nonetheless, we invented the technology of agriculture about 11,000 years ago, and since then have been modifying our diet to include more plant tissue and less animal tissue.

But the results have been disappointing. Life expectancy for an adult human with the good fortune to have survived childhood was 50-55 years at the end of the Mesolithic Era, when we were nomadic hunter-gatherers eating a lot of meat supplemented by herbs, nuts and berries. By the time of the Roman Empire 2,000 years ago, when we survived on a low-variety ovo-lacto-vegetarian (but not vegan) diet of grains and dairy products, life expectancy had plummeted to the low 20s.

Amino acids are the building blocks of protein, and there is a set of twelve (IIRC) that our metabolism can't synthesize from the others, so we have to ingest them. But the "Diet for a Small Planet" science of fifty years ago figured out how to get those amino acids from plant sources. You have to have the right balance of grains with nuts and seeds, and it's not really hard if you just keep track.

The real problem with the Industrial Era diet was lack of vitamins and minerals, and that was not so much the result of a lack of meat, as of a lack of variety, and specifically some foolish trends like processing plant food sources and shucking or rinsing away some of their most valuable components. Things like potato skins, wheat germ and the broth from cooked vegetables are rich sources of nutrition, and it became trendy to toss that stuff out for the hogs.

People generally tried to eat a lot of milk and eggs, and that stuff has the same amino acid content as meat. Which is why a vegetarian diet is easier to balance without having a PhD in nutritional science, than a vegan diet.

As a statistical statement, EVERYBODY in Western civilization eats meat! Vegetarians are regarded as odd and we think vegans are just plain kooky. Humans have a taste for meat just as we have a taste for sweets. We inherited the former from our most recent ancestors, and the latter from the shrews who climbed up into the first fruit-bearing trees to sink their teeth into that sweet goodness, and were the ancestors of the sloths and then the primates.

You can concoct a diet of pure plant tissue that has all the correct amino acids and vitamins and minerals, and it will keep you alive and healthy. With today's chemistry, you can even make it taste halfway decent if you weren't spoiled by a momma who was an outstanding cook. But it does not FEEL like meat in our mouths, and that leaves one of our most fundamental instincts unsatisfied.

It might have been true five thousand years ago, but not today. Our brains do indeed require a lot of protein for maintenance. But as I've pointed out, we know how to put the amino acids in grains together with the amino acids in nuts and seeds, so we get the equivalent of the protein in meat.

The various human species have been hunters for a long time, including the Homo neanderthalensis that you're probably referring to. Our brains evolved into large organs over the millennia as much from natural selection as diet. The smarter humans had a better chance at survival.

Still, your point is well taken. Dogs and wolves are two subspecies of a single species, Canis lupus. When dogs came to live with us, they adapted to become more of a scavenger than a hunter, eating the bounty of garbage we left all over our camps. There are a couple of noteworthy physical changes that came with that. One is a slight difference in their teeth, which are not quite as efficient at ripping raw flesh as a wolf's teeth. The other is their brains. Dogs eat less protein than wolves, and their brains are smaller relative to their body size.