There are a lot of examples of this in the book The Secret of Our Success (which argues that human cultures have a lot of culturally-evolved knowledge which individuals would be very unlikely to develop in a single generation, and which often provides benefits for reasons that aren't consciously understood by the actual members of the culture, while occasionally including some noise or bad advice).

Many of those are traditions or ritual behaviors that decrease the chance of poisoning, sometimes subtle chronic poisoning rather than obvious acute poisoning.

> It's probably not a bad idea to try to figure out why a tradition is there before you mess around.

Interestingly, I think the rest of your comment supports exactly the opposite message. Traditional food preparation is the way it is for excellent reasons, that's true.

And what's also true is that you have absolutely no hope of determining what those reasons are. You can mess around and see if you get problems. But if you don't do that, you'll never have any idea what's behind the traditions. Investigating the question before messing around would be a gigantic waste of time and effort.

Chesterton's Fence

https://fs.blog/chestertons-fence/