It tastes so fucking good, though

Explanation: One of the favorite sweeteners of Romans was a concoction called defrutum, which was grape juice boiled down into a sweet syrup. Sounds harmless enough, right?

Well, it was boiled down into syrup in lead vessels. Specifically, lead vessels, because copper and iron alloys left an aftertaste; whereas lead reacted with the wine and made the resulting syrup sweeter.

What's worse, the Romans knew lead was unhealthy, both short and long-term.

But hell, what were the rich supposed to do?! Eat their fancy fruit and ice desserts without additional sweeteners??