All of human history has been much more dangerous in general than the current time, and dangerous food has always been one of the risks, at levels we would currently find shocking and unacceptable. The tradeoff is that starvation and malnutrition have also been serious concerns for all of human history, too. Your grocery store, full of safe and abundant food, is the historical exception, not the norm.

For example, as recently as a century or two ago, milk routinely killed people. https://en.m.wikipedia.org/wiki/Milk_sickness

The problems the UK dealt with in the 1800s sound horrifying. https://edu.rsc.org/feature/the-fight-against-food-adulterat...

And adulturated food in general was a serious problem in the US, in times still within living memory. https://en.m.wikipedia.org/wiki/Early_history_of_food_regula...

In some ways, it still is. A lot of people advocate avoiding processed food entirely, as a way to dodge these sorts of bullets.