For today's historical bit of stupidity, we go to Sweden in the 1700's, and King Gustav III. Gustav didn't think much of coffee. It was fairly widely consumed in Europe at that time, but Gustavus thought it to be poison. He set out to prove it.
It just so happened that in a Stockholm, he happened to have two twin brothers condemned to death. The perfect foils for a little experiment. In lieu of being actively executed, Gustav would order one to drink three pots of coffee a day, and the other three pots of tea, as a control. Then they'd simply wait and, under the watch of two doctors, see who died first. Surely, the coffee drinker wouldn't last very long.
So who was the first to die? The head doctor. The prisoners, of course, weren't going anywhere. Soon thereafter, the other doctor died. Still no sign of weakness from the prisoners.
Okay, fine, then. We still have a coffee drinker and a tea drinker. Who dies first?
King Gustav III, that's who. In 1792, he was assassinated at the Royal Opera House. Or at least, he was shot, and died two weeks later from an infected wound.
The two brothers, though, continued to drink, though it's uncertain whether they were at this point ordered to continue or whether they themselves decided to keep it up. Finally, though, one of them did actually die.
At age 83.
It was the tea drinker. (The coffee drinker would last a few years longer; I've seen end ages of 85 and 87.)