Humans eating human meat making people go crazy is actually a myth I think. The reason people thought it was a thing was because of a small group of Indonesian (I think) indigenous people who ate dead relatives as part of funeral rites. Only children and women were getting sick with a "laughing disease" because they ate the dead. The underlying cause was a prion disease that could be carried without symptoms and that just ripped through their population over a few generations. That account is why people think cannibalism is bad for you, but if I recall correctly, prion diseases are not actually widespread enough for this to be a major concern. In terms of health, most human meat should be safe for consumption.

Obviously ethically we probably should not normalize eating people though.