I have heard that you can die from eating too hot or too many chili peppers (see here). Is this even theoretically possible? How much peppers would you have to eat to be in any danger?
Theoretically, apparently yes:
But is there a deadly dose of spicy peppers? Researchers at Niigata University School of Medicine in Japan ran tests on mice to find out. After several hefty doses of pure capsaicin, most of the mice died of lung failure. Don't worry, though—you'd have to eat hundreds of thousands of jalapeños in one sitting to get the equivalent dose...
I tracked down the actual paper mentioned.
Another article cites Paul Bosland, professor of horticulture at New Mexico State University and director of the Chile Pepper Institute on the matter:
"Theoretically, one could eat enough really hot chiles to kill you," he says. "A research study in 1980 calculated that three pounds of extreme chilies in powder form — of something like the Bhut Jolokia — eaten all at once could kill a 150-pound person."
Three pounds of powder doesn't really seem like "eating peppers" to me -- this seems like a modification of the ingredients to cause the actives to be absorbed faster and take effect.
So, let's take the hottest pepper, the Bhut Jolokia mentioned above, and try to figure out how much one would have to eat of it.
Here's our data:
- LD50 for capsaicin (active spicy ingredient in peppers) is 47.2 mg/kg in mice
- Bhut Jolokia peppers have 2.06% weight/weight capsaicin content
- Average human body weight: 86.6kg (using heaviest male average from US)
So we need to solve:
47.2mg/kg × 86.6kg = LD50 dosage = 0.0206 × mass of peppers to ingest
This gives us 198,423.3mg ≈ 0.2kg (≈ 1/2 lb) of these peppers one would have to eat. I say that's doable. The open question is whether the LD50 in mice is transferable to humans.
Per @wjl's comment, Wikipedia lists Bhut Jolokia weight at 7-9g per pepper, so we're talking 22-28 peppers to reach the 0.2kg (200g) value.
The World's Hottest Chilli eating contest in Edinburgh this year did end with two of the contestants being rushed to hospital by ambulance - vomiting, agony - not good.
It isn't evidence, however it is a good indicator that you can seriously upset the body even with just a few spoonfuls of hot chilli, so it isn't a great leap of faith...