It's not that the Paleolithic environment was optimal for humans, but humans were optimized to survive in that environment. You can somewhat expect that the hu

It's not that the Paleolithic environment was optimal for humans, but humans were optimized to survive in that environment. You can somewhat expect that the human body will do a decent job at surviving anything in that environment. Now there are undoubtedly environments that are better for humans than the Paleolithic one. However, it's hard to say for sure what they are specifically. Every chemical that enters your body has some effect, and if your body was never optimized to handle it, it may have negative effects, even if on the surface it seems better. Trans fats are a great example of this. If we had been eating them for 10,000 years, our bodies would have adapted to make them non-harmful.