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humans should avoid eating mammals
2014-Dec-30, Tuesday 08:44 pmScientists may have finally discovered why red meat is bad for humans. Vegetarians score a big win with this new discovery, because the consequence is inescapable for any of us. Given that this genetic change appeared 2-3 million years ago as the Homo genus made its appearance in the world, it seems that we (unlike modern apes) are designed specifically not to eat red meat.
We already know that red meat is associated with poor health in humans, linked to conditions as varied as arthritis, heart disease, and different cancers. Nobody, though, had a clear and concise explanation for these associations. I figured it was mostly our modern livestock production system (antibiotics, chemical-laced foods, inhumane conditions, etc.) that was to blame, but it turns out that humans evolved a unique biological difference from other mammals... and it leaves those other mammals noxious to us as food sources.
Most other mammals (including other apes) produce a kind of sugar whose long name is N-Glycolylneuraminic acid and whose shortened name is Neu5Gc. This simple sugar ends up in their meat and their milk. Humans, however, are incapable of producing this molecule. It is thought that we evolved this deficit because it made us immune to a form of malaria while other mammals are still susceptible to infection. Neu5Gc is a natural substance and non-cancerous in itself, but it is now foreign to us. When we eat this food, our immune systems develop an antibody response to it. That antibody reaction then produces inflammation, and the chronic inflammation from daily exposure leads to cancers and other ills.
Researchers created mice with the same Neu5Gc deficiency that humans have, then they fed them with Neu5Gc.
Chronic exposure with antibodies caused tumor development, and those tumors were rich in Neu5Gc deposits even though the mouse cells could not produce the substance. It appears that they discovered the "smoking gun" that explains why red meat is bad for human health. I look forward to the human trials that can conclusively show the same link.
I've been semi-vegetarian for many years already. I have many meatless days by happenstance. I did not choose this lifestyle for humanitarian concerns. I am the only person responsible for my food, and I simply don't trust myself to store and cook meat properly for safe consumption. Instead, I eat meat when I go out to restaurants. It's not clear at this point what amount of Neu5Gc exposure is safe (unlikely to trigger antibodies), if any at all.
Like the Whos down in Whoville, maybe it's time that we switched to a healthy (but humane) roast beast?
We already know that red meat is associated with poor health in humans, linked to conditions as varied as arthritis, heart disease, and different cancers. Nobody, though, had a clear and concise explanation for these associations. I figured it was mostly our modern livestock production system (antibiotics, chemical-laced foods, inhumane conditions, etc.) that was to blame, but it turns out that humans evolved a unique biological difference from other mammals... and it leaves those other mammals noxious to us as food sources.
Most other mammals (including other apes) produce a kind of sugar whose long name is N-Glycolylneuraminic acid and whose shortened name is Neu5Gc. This simple sugar ends up in their meat and their milk. Humans, however, are incapable of producing this molecule. It is thought that we evolved this deficit because it made us immune to a form of malaria while other mammals are still susceptible to infection. Neu5Gc is a natural substance and non-cancerous in itself, but it is now foreign to us. When we eat this food, our immune systems develop an antibody response to it. That antibody reaction then produces inflammation, and the chronic inflammation from daily exposure leads to cancers and other ills.
Researchers created mice with the same Neu5Gc deficiency that humans have, then they fed them with Neu5Gc.
When such mice were challenged with anti-Neu5Gc antibodies, they developed evidence of systemic inflammation. Long-term exposure to this combination resulted in a significantly higher incidence of carcinomas (five-fold increase) and an association with Neu5Gc accumulation in the tumors. Similar mechanisms may contribute to the association of red meat consumption with other diseases, such as atherosclerosis and type 2 diabetes, which are also exacerbated by inflammation.
- http://www.pnas.org/content/early/2014/12/25/1417508112.abstract
- http://www.pnas.org/content/early/2014/12/25/1417508112.abstract
Chronic exposure with antibodies caused tumor development, and those tumors were rich in Neu5Gc deposits even though the mouse cells could not produce the substance. It appears that they discovered the "smoking gun" that explains why red meat is bad for human health. I look forward to the human trials that can conclusively show the same link.
I've been semi-vegetarian for many years already. I have many meatless days by happenstance. I did not choose this lifestyle for humanitarian concerns. I am the only person responsible for my food, and I simply don't trust myself to store and cook meat properly for safe consumption. Instead, I eat meat when I go out to restaurants. It's not clear at this point what amount of Neu5Gc exposure is safe (unlikely to trigger antibodies), if any at all.
Like the Whos down in Whoville, maybe it's time that we switched to a healthy (but humane) roast beast?