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Mnementh said: (1) [...omnivore?...] (2) It has been shown that prehistoric men used the resources they found. While the northern tribes usually put together as eskimos have suaully eaten mostly fish and meat of seals and caribous, other regions used more fruit or meat of big animals. This really differs a lot depending on there it was located. Seemingly being able to digest a broad range of foods allowed the humans to settle all over the world. (3) There are also a lot of study that show connection between some plant foods and diseases. For instance tomato and testicular cancer. That is all difficult, because humans are no lab, results are difficult to reproduce and are dependent on a lot of cofactors. (4) [...]As I research it, the stand in english literature is a bit different, but still recommends the suplements. This is also clearly right, as a deficience of B12 especially while grwoing up leads to permanent brain and nerve damage. But the supplements can be produced andare also vegan as the Vitamin is synthesized in a chemical lab. With these supplement it is all right. (5) I know it comes from bacteria, like a lot of chemical substances. Plants don't need B12, as they have no bervous system. Vertebrate do need it though. They usually have these bacteria inside their intestines. But these bacteria need time to break down foods and create B12. And here is the kicker: most herbivores have very long intestines (see above) and therefore the food stays long enough for the bacteria to produce enough B12. Other herbivores with shorter intestines like the elephant need to eat all day (more than 20 hours a day). Not only because of B12, but because their intestines aren't breaking down the plant food well enough to extract a lot of nutrients. Another group of herbivores like hare eat their own feces, to get the B12 bacteria produced and have a chance of another full round. Omnivores and carnivores get the missing B12 they don't produce themself from animals they eat. |
1) I agree that intestinal length is not the primary criteria. What is then? Most (all?) omnivores have the ability to create vitamin C in their body, as the biologically ideal omnivore can thrive on just plants, or just animals. That's true of wolves and canines, they can thrive on just meat because A) their bodies produce vitamin C so they don't need to consume it, and B) because their bodies have a mechanism to get rid of excess cholesterol. Humans have the gene for creating vitamin C in our bodies, but it turned itself off hundreds of thousands (perhaps millions) of years ago because we ate mostly fruit and didn't lack for it. Our bodies producing vitamin C would have more likely lead to an overdose than to ideal health, so we evolved in such a way as to turn it off. A cat is considered a pure carnivore, yet can subsist on a plant-based diet for a time. A cow is considered a pure herbivore, but could subsist of off animal products for a time. Our ability to subsist off of animal products is therefore not surprising, but we're more herbivorous than otherwise so it's not surprising that eating even tiny amounts of meat dramatically increase the likelihood of us getting a raft of diseases. We *can* eat meat, but we don't thrive on it.
2) Of course the inuit (Eskimo is considered a perjorative term by many nothern peoples, BTW) ate mostly meat. They also were very unhealthy because of it. Studies on inuit mummies showed signs of heart disease, and they lived far shorter lives than aboriginal peoples who lived even only a little bit further south.
3) I'd have to see studies on tomatoes and cancer to comment, but of course some plant foods are less healthy than others. Oreo cookies are a plant-based food for that matter! :P Not all plant-based foods are created equal, and not all should be consumed with abandon. Everyone should have a diet plan and follow it, IMO. I don't eat tomatoes (or Oreo cookies, for that matter). :)
4) Ich spreche ein bißchen Deutsche, but nur ein bißchen. :) The argument that vegan diets don't cover every nutrient unless carefully crafted is absolutely true. But lost in that discussion is that omnivorous diets tend to be far worse. The average vegan in North America is deficient in three essential nutrients, but the average omnivorous diet is deficiednt in *seven* essential nutrients. And that's despite the fact that many vegans choose it for ethical reasons rather than health, so they may be eating a lot of processed food. (Source posted a couple of times in recent posts here.)
5) My understanding is that we traditionally got vitamin B12 not from out intestines, but from our mouths. The bacteria that creates B12 would live in our mouthes, and the B12 it created would be absorbed into our bloodstream under our tongues. Water treatment, toothpaste, and mouthwash put an end to that which requires supplementing. Guess what though? Omnivores are getting B12 supplements too, and B12 supplements are now routinely given to farm animals since they are usually factory farmed and also don't get B12 from bacteria anymore. SOURCE: http://baltimorepostexaminer.com/carnivores-need-vitamin-b12-supplements/2013/10/30#sthash.RerFgkfc.dpuf If you believe that omnivores get B12 from eating meat, then that strengthens the argument that we're herbivores as we have a mechanism for hosting the bacteria in our body to get the B12 that way.
Ultimately, most of what you say is true, but the context is important and there's more to this story. The peoples across the world that eat the most plants and the least meat are the healthiest, the longest-living, and the most vibrant in old age. When a population increases its consumption of meat, dairy, and eggs, its health declines. Look at Okinawa, which went from the most whole food plant-based and the most healthy in Japan, to the least whole food plant-based and the least healthy in Japan in just one or two generations. Counter-arguments to this are based on theory, but it's theory that doesn't hold up when you put it to the test (eg. theories that eating more cholesterol doesn't raise cholesterol levels fail when put to the test in before-and-after comparison studies).
