Carnivory and veganism
We should be basing our food choices on what is best for our body.
What most of us choose to eat is decided mainly by the food industry and their advertising agencies. That is most unlikely to be in our best interests! Given a free choice, animals in the wild continue to eat what is best for their bodies. They depend on intuition and just keep eating the same old food. Boring but appropriate for their metabolism. Incidentally it helps them maintain the ideal weight, healthy teeth etc
We now have lots of reliable evidence enabling us to look back at how man has evolved from our ape-like forebears. We can trace back to the earliest mammals, and then further back to when their ancestors emerged from the oceans and started to walk on land.
Study of these fascinating timelines reveals interesting facts:
Virtually all fish are carnivores.
The earliest land animals, 360 million years ago, reptiles and amphibians were, and still are, carnivores. Their livers metabolise food just as ours do.
The first mammal to appear 160 million years ago was a carnivore.
There was plenty of food in the tropical climate and the huge increase in plants and animals led to a wide choice of both plant and animal food.
70 million years ago, was the first major global cooling event. The oceans around the poles turned to ice which led to a dramatic fall in sea level. Much of the lush jungle cooled to the point where it turned into open landscapes covered with grass. The dinosaurs became extinct following a giant meteor collision with earth. Ruminant animals capable of thriving on a diet of grass evolved and were massively successful.
7 million years ago, it was choice time for apes, plants or meat. Some apes chose plant food, developed a large gut to enable digestion of tough plants and lived where there was plenty of food close by in the remaining jungle. After supplying the gut there was just enough energy remaining for a small 350ml brain.
Other apes gradually learned to become carnivores. Killing animals and eating their meat, just as most of their ancestors had done, provided a food that was much more energy dense and easy to digest. There were animals to prey on by the million all over the planet. The apes that ate predominantly meat required a small gut leaving surplus energy for their brains to grow from 350ml to 1,500ml.
About 200,000 years ago modern man evolved with his big brain, tall stature and an ability to hunt over long distances during the day. He hunted animals rather than gathering plants. There is strong fossil isotope evidence that humans were the top level carnivores eating meat and fish.
Then things started to go wrong. Instead of living on our planet without disturbing it, we started altering it. We entered the age of the Anthropocene, when man became a significant influence on the climate and our environment. Human intelligence sowed the seeds for our undoing starting with the extinction of the megafauna. About 60,000 years ago, man reached Australia and found 2 tonne wombats and 1,000 kilo kangaroos. These were exterminated for food.
About 12,000 years ago the next major problem arose: the first agricultural revolution. Man worked out how to farm wheat, arguably a big mistake. It resulted in a huge increase in food supply. Humans settled in the Fertile Crescent in the Middle East, creating cities. There was a population explosion. The irregular supply of water from rivers required supplementation by irrigation. Before long, rival cities such as Babylon and Uruk went to war over food.
The evolution of the slave trade, 1619 to 1865, enabled the second agricultural revolution to combine with the rise of capitalism to produce cheap tobacco, sugar and eventually, cotton seed oil.
The second half of the 19th century saw two other important changes caused by man’s intelligence. The industrial revolution enabled a transformation in the way food was produced. Nature gave way to manufacture. The windmill producing stone ground flour was replaced by the steam driven steel roller mill. Highly refined white sugar was invented. Suddenly cheap carbohydrate, sugar and starch, was readily available.
The concept of a vegetarian diet being superior to the food humans had eaten for millenia was first propounded by the ancient Greeks but was warmly embraced in the late 1800s by the newly formed 7th Day Adventist Church, led by Ellen G White, hand in hand with an early prominent recruit to the cause, Dr John Harvey Kellogg of Corn Flakes fame. They believed that: “A religious life can be more successfully gained and maintained if meat is discarded, for this diet stimulates intense activities, lustful propensities, and enfeebles the moral and spiritual nature.“
Their teachings quickly dominated the emerging science of dietetics. In the 1960s doctors and politicians proposed the Diet Heart Hypothesis with the hope of reversing the rising tide of heart attacks. These diseases are now known to be caused primarily by excess sugar, carbohydrates and tobacco, with a contribution from seed oils but in the mid-70s, fat, particularly animal fat, was thought to cause.
This is arguably one of the worst medical blunders of all time. The introduction of the 1977 dietary guidelines marked the beginning of a dramatic upsurge in the incidence of obesity, type 2 diabetes and other manifestations of what is now known as the metabolic syndrome. The Diet Heart Hypothesis failed and should never have become established but these guidelines remain, largely unamended to this day.
The modern standard American or Australian diet is a disaster. Switching to a well-constructed vegan or vegetarian diet is a significant improvement. However, optimal health is more readily achieved following the example of our ancestors by eating a meat-based diet supplemented with plants when sufficient meat is not available.
It is not appropriate to invoke ethics or innate plant food superiority when considering human metabolism.