> Things are not necessarily safe just because they're natural
Whatever "natural" means. It's not wrong exactly, but I think it distracts from some adjacent, non-fallacious inductive/anthropic reasoning:
> Things that have not harmed your ancestors are less likely to harm you than a novel thing which your ancestors did not come in contact with.
The former (safer) thing is more likely to end up with the label "natural" than the latter, newer thing. So "natural" ends up correlating with "safe" more often than chance would have it.