Ah, but was it the consumption of fish and other animals that gave way to the explosive growth of the human brain?
On another note, I believe you can heal on a vegan diet and may actually find it easier to do if you are consuming foods (raw in some cases) that are easier to digest and subsequently, assimilate nutrients.
But I like chicken or fish every now and again, but I don't consume dairy or eggs (because of intolerance for eggs and milk is for baby calfs IMO).