I'd imagine it's also influenced by our stomach acid which plays a pretty substantial part in killing off most of the nasty things that could make us ill, altho

I'd imagine it's also influenced by our stomach acid which plays a pretty substantial part in killing off most of the nasty things that could make us ill, although most of those same nasty things have defensive mechanisms that can help them survive the initial onslaught of the acid (high protein foods seem to provide some refuge [1]). Your comment reminded me of a YouTube channel I find weirdly (perhaps morbidly) fascinating [2]. Once your body is acclimated to eating dubious quality materials, even in modern society, it seems that you're less likely to get sick provided you're still relatively careful (not that I'd recommend it). Steve1989 has gotten sick from his adventures, although surprisingly it was from a more recent Ukranian MRE contaminated with E. coli, and not from some of the more expected sources. It's worth watching a few of his videos if you can stomach it, if not for the surprise at what questionable materials he actually gets down, but for the unusual number and types of things that have survived (he's eaten a cookie from 1951, 61 year old peanut butter, and even Civil War era hardtack). I guess my memory was triggered by your mention of numb lips. As I understand it from the channel above, rancid nuts are particularly bad at causing numbness and swelling. I certainly wouldn't recommend trying anything of the sort unless you were absolutely desperate! Definitely check out his channel. It's gross, I'll warn you, but it's also fascinating. [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC106573/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC106573/ [2] https://www.youtube.com/channel/UC2I6Et1JkidnnbWgJFiMeHA/videos https://www.youtube.com/channel/UC2I6Et1JkidnnbWgJFiMeHA/vid...