With one notable exception (breastfeeding), we avoid eating human bodily secretions. The idea disgusts us because human secretions usually:
- Have a negligible nutritional value for humans (because our bodies don’t waste valuable resources if they can afford it)
- Have lots of disease bearing bacteria, already adapted to living inside human beings.
This is completely not analogous to chicken eggs, which are very nutritious because the content is supposed to feed a fetus chick. Because our fetuses stay inside mama and get fed through the umbilical, the human analog would be to eat an aborted fetus (warning, disgustingly graphic picture).
However, I think most of us don’t think chickens and humans are equivalent. Although some people do appear to have bird brains.
I got the meme from Dawn Geisler, but the refutation is my own.